Lymphangioma is a benign (noncancerous) tumor or malformation that occurs due to the abnormal development of the lymphatic system, a part of the immune system that helps fight infection and eliminate waste products. Lymphangiomas are typically composed of dilated lymphatic vessels filled with clear fluid called lymph. These masses can occur in various parts of the body but are most commonly found in the head, neck, and axilla (armpit) regions.

There are three main types of lymphangiomas:

1. Capillary lymphangioma: Also known as "lymphangiectasia" or "lymphangiomatosis," this is the most superficial and least aggressive type, often presenting as small vesicles or blisters on the skin.
2. Cavernous lymphangioma: This type consists of larger, more dilated lymphatic spaces and can involve deeper tissues. It usually appears as a soft, compressible mass beneath the skin.
3. Cystic hygroma: A subtype of cavernous lymphangioma, cystic hygromas are typically found in the neck or axilla regions and present as large, fluid-filled sacs or cysts.

Lymphangiomas can cause various symptoms depending on their size and location, including swelling, pain, infection, difficulty swallowing, or breathing problems if they compress vital structures such as airways or blood vessels. Treatment options may include surgical excision, sclerotherapy (injection of a substance to shrink the lesion), or observation, depending on the individual case and patient's preferences.

Cystic lymphangioma is a benign (noncancerous) tumor that develops in the lymphatic system, which is a part of the immune system. It is typically present at birth or appears in early childhood. The tumor is caused by the abnormal development of lymphatic vessels, resulting in the formation of cystic spaces filled with lymph fluid.

Cystic lymphangioma can occur anywhere in the body but are most commonly found in the head and neck region, particularly in the tongue, mouth, and throat. They may also appear in the armpits or groin. The tumor usually grows slowly and can cause various symptoms depending on its location. For example, a cystic lymphangioma in the throat can cause difficulty breathing, swallowing, or speaking.

Treatment options for cystic lymphangioma include surgical removal of the tumor, sclerotherapy (injection of a solution that causes the cysts to harden and shrink), or observation if the tumor is not causing any symptoms. The choice of treatment depends on various factors, including the size and location of the tumor, as well as the patient's age and overall health.

Picibanil is not a commonly used medical term, and it may be more familiar as the brand name for a specific preparation of Group A Streptococcus OK-432. It is an immunotherapeutic agent that has been used in Japan for the treatment of certain types of cancer, such as nasopharyngeal carcinoma and soft tissue sarcoma.

Group A Streptococcus OK-432 is a weakened form of a bacterium that causes strep throat. When administered, it stimulates the immune system to produce cytokines, which are substances that help regulate the immune response. This can enhance the body's ability to fight off cancer cells and potentially slow or stop tumor growth.

It is important to note that Picibanil/OK-432 is not approved for use in the United States and its effectiveness as a cancer treatment has not been extensively studied outside of Japan.

A Mesenteric Cyst is a rare, benign abdominal mass that forms within the mesentery, which is the fold of membrane that attaches the intestine to the abdominal wall and contains blood vessels, lymphatic vessels, and nerves. These cysts can vary in size from a few centimeters to several inches in diameter. They are typically asymptomatic but can cause symptoms such as abdominal pain, bloating, or a palpable mass, depending on their size and location. The exact cause of mesenteric cysts is not well understood, but they may be congenital or acquired due to trauma, inflammation, or surgery. Treatment usually involves surgical removal of the cyst.

Mediastinal neoplasms refer to abnormal growths or tumors located in the mediastinum, which is the central compartment of the thoracic cavity that lies between the lungs and contains various vital structures such as the heart, esophagus, trachea, blood vessels, lymph nodes, and nerves. Mediastinal neoplasms can be benign (non-cancerous) or malignant (cancerous), and they can arise from any of the tissues or organs within the mediastinum.

Benign mediastinal neoplasms may include thymomas, lipomas, neurofibromas, or teratomas, among others. These tumors are typically slow-growing and rarely spread to other parts of the body. However, they can still cause symptoms or complications by compressing adjacent structures within the mediastinum, such as the airways, blood vessels, or nerves.

Malignant mediastinal neoplasms are cancerous tumors that can invade and destroy surrounding tissues and may spread (metastasize) to other parts of the body. Common types of malignant mediastinal neoplasms include thymic carcinomas, lymphomas, germ cell tumors, and neuroendocrine tumors. These tumors often require aggressive treatment, such as surgery, radiation therapy, and chemotherapy, to control their growth and spread.

It is important to note that mediastinal neoplasms can present with various symptoms depending on their location, size, and type. Some patients may be asymptomatic, while others may experience cough, chest pain, difficulty breathing, hoarseness, or swallowing difficulties. A thorough diagnostic workup, including imaging studies and biopsies, is necessary to confirm the diagnosis and determine the best course of treatment for mediastinal neoplasms.

Intestinal volvulus is a serious medical condition that occurs when a segment of the intestine twists around itself, cutting off its blood supply. This can lead to tissue death and perforation of the intestine if not promptly treated. Intestinal volvulus can occur in any part of the intestine but is most common in the colon, particularly in the sigmoid colon.

Volvulus can be caused by a variety of factors, including congenital abnormalities, adhesions from previous surgeries, and conditions that cause the intestines to become mobile or elongated. Symptoms of intestinal volvulus may include severe abdominal pain, nausea, vomiting, bloating, and constipation. In some cases, a physical examination or imaging tests such as X-rays or CT scans may be used to diagnose the condition.

Treatment for intestinal volvulus typically involves surgery to untwist the intestine and restore blood flow. In some cases, a portion of the intestine may need to be removed if it has been damaged beyond repair. Preventative measures such as avoiding constipation and seeking prompt medical attention for abdominal pain can help reduce the risk of developing intestinal volvulus.

Splenic neoplasms refer to abnormal growths or tumors in the spleen, which can be benign (non-cancerous) or malignant (cancerous). These growths can arise from various cell types present within the spleen, including hematopoietic cells (red and white blood cells, platelets), stromal cells (supporting tissue), or lymphoid cells (part of the immune system).

There are several types of splenic neoplasms:

1. Hematologic malignancies: These are cancers that affect the blood and bone marrow, such as leukemias, lymphomas, and multiple myeloma. They often involve the spleen, causing enlargement (splenomegaly) and neoplastic infiltration of splenic tissue.
2. Primary splenic tumors: These are rare and include benign lesions like hemangiomas, lymphangiomas, and hamartomas, as well as malignant tumors such as angiosarcoma, littoral cell angiosarcoma, and primary splenic lymphoma.
3. Metastatic splenic tumors: These occur when cancer cells from other primary sites spread (metastasize) to the spleen. Common sources of metastasis include lung, breast, colon, and ovarian cancers, as well as melanomas and sarcomas.

Symptoms of splenic neoplasms may vary depending on the type and extent of the disease but often include abdominal pain or discomfort, fatigue, weight loss, and anemia. Diagnosis typically involves imaging studies (such as ultrasound, CT, or MRI scans) and sometimes requires a biopsy for confirmation. Treatment options depend on the type of neoplasm and may include surgery, chemotherapy, radiation therapy, targeted therapy, or immunotherapy.

The mesentery is a continuous fold of the peritoneum, the double-layered serous membrane that lines the abdominal cavity, which attaches the stomach, small intestine, large intestine (colon), and rectum to the posterior wall of the abdomen. It provides blood vessels, nerves, and lymphatic vessels to these organs.

Traditionally, the mesentery was thought to consist of separate and distinct sections along the length of the intestines. However, recent research has shown that the mesentery is a continuous organ, with a single continuous tethering point to the posterior abdominal wall. This new understanding of the anatomy of the mesentery has implications for the study of various gastrointestinal diseases and disorders.

Jejunal neoplasms refer to abnormal growths or tumors in the jejunum, which is the middle section of the small intestine. These neoplasms can be benign (non-cancerous) or malignant (cancerous). Malignant jejunal neoplasms are often aggressive and can spread to other parts of the body, making them potentially life-threatening.

There are several types of jejunal neoplasms, including:

1. Adenocarcinomas: These are cancerous tumors that develop from the glandular cells lining the jejunum. They are the most common type of jejunal neoplasm.
2. Carcinoid tumors: These are slow-growing neuroendocrine tumors that arise from the hormone-producing cells in the jejunum. While they are usually benign, some can become malignant and spread to other parts of the body.
3. Gastrointestinal stromal tumors (GISTs): These are rare tumors that develop from the connective tissue cells in the jejunum. They can be benign or malignant.
4. Lymphomas: These are cancerous tumors that develop from the immune system cells in the jejunum. They are less common than adenocarcinomas but can be aggressive and spread to other parts of the body.
5. Sarcomas: These are rare cancerous tumors that develop from the connective tissue cells in the jejunum. They can be aggressive and spread to other parts of the body.

Symptoms of jejunal neoplasms may include abdominal pain, bloating, diarrhea, weight loss, and bleeding in the stool. Treatment options depend on the type and stage of the neoplasm but may include surgery, chemotherapy, radiation therapy, or a combination of these approaches.

"Acute abdomen" is a medical term used to describe a sudden and severe abdominal pain that requires immediate medical attention. This condition can be caused by various factors such as inflammation, infection, obstruction, or perforation of the abdominal organs. Common causes of acute abdomen include appendicitis, cholecystitis, diverticulitis, intestinal obstruction, and perforated ulcers.

The symptoms of acute abdomen may include severe and localized or generalized abdominal pain, tenderness, rigidity, rebound tenderness, fever, nausea, vomiting, and loss of appetite. The diagnosis of acute abdomen is usually made based on the patient's history, physical examination, laboratory tests, and imaging studies such as X-rays, ultrasound, or CT scan.

Treatment of acute abdomen depends on the underlying cause and may include antibiotics, intravenous fluids, pain management, and surgery in severe cases. Delayed diagnosis and treatment of acute abdomen can lead to serious complications such as sepsis, peritonitis, and even death.

Klippel-Trenaunay-Weber Syndrome (KTWS) is a rare and complex congenital vascular disorder that affects the development of blood vessels, soft tissues, and bones. It is also known as Klippel-Trenaunay syndrome or KTS.

The medical definition of KTWS includes the following features:
1. Port-wine stain (capillary malformation): A red or purple birthmark caused by an abnormal collection of blood vessels in the skin, often present at birth and usually affecting one limb or part of the body.
2. Venous and lymphatic abnormalities: Varicose veins, dilated veins, or abnormal vein patterns may be present, along with lymphatic malformations that can cause swelling in the affected area.
3. Soft tissue and bone hypertrophy: Overgrowth of soft tissues and bones in the affected limb or region, leading to asymmetry and sometimes functional impairment.
4. Other possible features: May include skin abnormalities, such as increased hair growth or changes in texture; joint deformities; and orthopedic problems, like scoliosis or hip dysplasia.

It is important to note that the severity of KTWS can vary significantly from person to person, ranging from mild symptoms to severe cases with significant functional impairment. The condition is not typically life-threatening but may require ongoing medical management and surveillance to address potential complications, such as infections, bleeding, or deep vein thrombosis.

Kasabach-Merritt syndrome (KMS) is a rare but serious condition characterized by the combination of a large hemangioma or tufted angioma (benign vascular tumors) with severe thrombocytopenia (low platelet count) and consumptive coagulopathy (a disorder of blood clotting).

The syndrome is named after the two physicians who first described it in 1940. It primarily affects infants, with about 70% of cases diagnosed before the age of one month.

In KMS, the hemangioma or tufted angioma grows rapidly and becomes a consumptive coagulopathy due to platelet trapping within the lesion, leading to profound thrombocytopenia. This can result in bleeding complications, which can be life-threatening if not promptly treated.

The treatment of KMS typically involves a combination of medical management (such as corticosteroids, interferon, and vincristine) and surgical intervention to remove the hemangioma or tufted angioma. In some cases, embolization of the lesion may also be considered.

Macroglossia is a medical term that refers to an abnormally large tongue in relation to the size of the oral cavity. It can result from various conditions, including certain genetic disorders (such as Down syndrome and Beckwith-Wiedemann syndrome), hormonal disorders (such as acromegaly), inflammatory diseases (such as amyloidosis), tumors or growths on the tongue, or neurological conditions. Macroglossia can cause difficulties with speaking, swallowing, and breathing, particularly during sleep. Treatment depends on the underlying cause but may include corticosteroids, radiation therapy, surgery, or a combination of these approaches.

Orbital neoplasms refer to abnormal growths or tumors that develop in the orbit, which is the bony cavity that contains the eyeball, muscles, nerves, fat, and blood vessels. These neoplasms can be benign (non-cancerous) or malignant (cancerous), and they can arise from various types of cells within the orbit.

Orbital neoplasms can cause a variety of symptoms depending on their size, location, and rate of growth. Common symptoms include protrusion or displacement of the eyeball, double vision, limited eye movement, pain, swelling, and numbness in the face. In some cases, orbital neoplasms may not cause any noticeable symptoms, especially if they are small and slow-growing.

There are many different types of orbital neoplasms, including:

1. Optic nerve glioma: a rare tumor that arises from the optic nerve's supportive tissue.
2. Orbital meningioma: a tumor that originates from the membranes covering the brain and extends into the orbit.
3. Lacrimal gland tumors: benign or malignant growths that develop in the lacrimal gland, which produces tears.
4. Orbital lymphangioma: a non-cancerous tumor that arises from the lymphatic vessels in the orbit.
5. Rhabdomyosarcoma: a malignant tumor that develops from the skeletal muscle cells in the orbit.
6. Metastatic tumors: cancerous growths that spread to the orbit from other parts of the body, such as the breast, lung, or prostate.

The diagnosis and treatment of orbital neoplasms depend on several factors, including the type, size, location, and extent of the tumor. Imaging tests, such as CT scans and MRI, are often used to visualize the tumor and determine its extent. A biopsy may also be performed to confirm the diagnosis and determine the tumor's type and grade. Treatment options include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

"Intralesional injection" is a medical term that refers to the administration of a medication directly into a lesion or skin abnormality, such as a tumor, cyst, or blister. This technique is used to deliver the medication directly to the site of action, allowing for higher local concentrations and potentially reducing systemic side effects. Common examples include the injection of corticosteroids into inflamed tissues to reduce swelling and pain, or the injection of chemotherapeutic agents directly into tumors to shrink them.

Hemangioendothelioma is a rare type of vascular tumor, which means it arises from the endothelial cells that line the blood vessels. It can occur in various parts of the body, but it most commonly involves the soft tissues and bones. Hemangioendotheliomas are often classified as borderline malignant tumors because they can behave either indolently (like a benign tumor) or aggressively (like a malignant tumor), depending on their specific type and location.

There are several subtypes of hemangioendothelioma, including:

1. Epithelioid hemangioendothelioma: This subtype typically affects young adults and can involve various organs, such as the liver, lungs, or soft tissues. It tends to have a more indolent course but can metastasize in some cases.
2. Kaposiform hemangioendothelioma: This is an aggressive subtype that usually occurs in infants and children. It often involves the skin and soft tissues, causing local invasion and consumptive coagulopathy (Kasabach-Merritt phenomenon).
3. Retiform hemangioendothelioma: A rare and low-grade malignant tumor that typically affects the skin and subcutaneous tissue of adults. It has a favorable prognosis with a low risk of metastasis.
4. Papillary intralymphatic angioendothelioma (PILA): This is a rare, slow-growing tumor that usually occurs in the head and neck region of children and young adults. It has an excellent prognosis with no reported cases of metastasis or recurrence after complete surgical resection.

Treatment for hemangioendotheliomas typically involves surgical excision when possible. Other treatment options, such as radiation therapy, chemotherapy, or targeted therapies, may be considered depending on the tumor's location, size, and behavior. Regular follow-up is essential to monitor for potential recurrence or metastasis.

Incidental findings are diagnoses or conditions that are discovered unintentionally while evaluating a patient for a different condition or symptom. These findings are not related to the primary reason for the medical examination, investigation, or procedure. They can occur in various contexts such as radiology studies, laboratory tests, or physical examinations.

Incidental findings can sometimes lead to further evaluation and management, depending on their nature and potential clinical significance. However, they also pose challenges related to communication, informed consent, and potential patient anxiety or harm. Therefore, it is essential to have clear guidelines for managing incidental findings in clinical practice.

Genital neoplasms in males refer to abnormal growths or tumors that develop in the male reproductive organs. These can be benign (non-cancerous) or malignant (cancerous).

Malignant genital neoplasms are often referred to as genital cancers. The most common types of male genital cancers include:

1. Penile Cancer: This occurs when cancer cells form in the tissues of the penis.
2. Testicular Cancer: This forms in the testicles (testes), which are located inside the scrotum.
3. Prostate Cancer: This is a common cancer in men, forming in the prostate gland, which is part of the male reproductive system that helps make semen.
4. Scrotal Cancer: This is a rare form of cancer that forms in the skin or tissue of the scrotum.
5. Penile Intraepithelial Neoplasia (PeIN): This is not cancer, but it is considered a pre-cancerous condition of the penis.

Early detection and treatment of genital neoplasms can significantly improve the prognosis. Regular self-examinations and medical check-ups are recommended, especially for individuals with risk factors such as smoking, HIV infection, or a family history of these cancers.

Retroperitoneal neoplasms refer to abnormal growths or tumors that develop in the retroperitoneal space. This is the area located behind the peritoneum, which is the membrane that lines the abdominal cavity and covers the abdominal organs. The retroperitoneal space contains several vital structures such as the kidneys, adrenal glands, pancreas, aorta, and lymphatic vessels.

Retroperitoneal neoplasms can be benign or malignant (cancerous). Malignant retroperitoneal neoplasms are often aggressive and can invade surrounding tissues and organs, leading to various complications. Common types of retroperitoneal neoplasms include lymphomas, sarcomas, and metastatic tumors from other primary sites. Symptoms may vary depending on the size and location of the tumor but can include abdominal or back pain, weight loss, and swelling in the legs. Diagnosis typically involves imaging studies such as CT scans or MRI, followed by a biopsy to determine the type and grade of the tumor. Treatment options may include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

Vulvar neoplasms refer to abnormal growths or tumors in the vulvar region, which is the exterior female genital area including the mons pubis, labia majora, labia minora, clitoris, and the vaginal vestibule. These neoplasms can be benign (non-cancerous) or malignant (cancerous).

Benign vulvar neoplasms may include conditions such as vulvar cysts, fibromas, lipomas, or condylomas (genital warts). They are typically slow-growing and less likely to spread or invade surrounding tissues.

Malignant vulvar neoplasms, on the other hand, are cancers that can invade nearby tissues and potentially metastasize (spread) to distant parts of the body. The most common types of malignant vulvar neoplasms are squamous cell carcinoma, vulvar melanoma, and adenocarcinoma.

Early detection and treatment of vulvar neoplasms are essential for improving prognosis and reducing the risk of complications or recurrence. Regular gynecological examinations, self-examinations, and prompt attention to any unusual symptoms or changes in the vulvar area can help ensure timely diagnosis and management.

Peritoneal neoplasms refer to tumors or cancerous growths that develop in the peritoneum, which is the thin, transparent membrane that lines the inner wall of the abdomen and covers the organs within it. These neoplasms can be benign (non-cancerous) or malignant (cancerous). Malignant peritoneal neoplasms are often associated with advanced stages of gastrointestinal, ovarian, or uterine cancers and can spread (metastasize) to other parts of the abdomen.

Peritoneal neoplasms can cause various symptoms such as abdominal pain, bloating, nausea, vomiting, loss of appetite, and weight loss. Diagnosis typically involves imaging tests like CT scans or MRIs, followed by a biopsy to confirm the presence of cancerous cells. Treatment options may include surgery, chemotherapy, radiation therapy, or a combination of these approaches, depending on the type, stage, and location of the neoplasm.

X-ray computed tomography (CT or CAT scan) is a medical imaging method that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of the body. These cross-sectional images can then be used to display detailed internal views of organs, bones, and soft tissues in the body.

The term "computed tomography" is used instead of "CT scan" or "CAT scan" because the machines take a series of X-ray measurements from different angles around the body and then use a computer to process these data to create detailed images of internal structures within the body.

CT scanning is a noninvasive, painless medical test that helps physicians diagnose and treat medical conditions. CT imaging provides detailed information about many types of tissue including lung, bone, soft tissue and blood vessels. CT examinations can be performed on every part of the body for a variety of reasons including diagnosis, surgical planning, and monitoring of therapeutic responses.

In computed tomography (CT), an X-ray source and detector rotate around the patient, measuring the X-ray attenuation at many different angles. A computer uses this data to construct a cross-sectional image by the process of reconstruction. This technique is called "tomography". The term "computed" refers to the use of a computer to reconstruct the images.

CT has become an important tool in medical imaging and diagnosis, allowing radiologists and other physicians to view detailed internal images of the body. It can help identify many different medical conditions including cancer, heart disease, lung nodules, liver tumors, and internal injuries from trauma. CT is also commonly used for guiding biopsies and other minimally invasive procedures.

In summary, X-ray computed tomography (CT or CAT scan) is a medical imaging technique that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional images of the body. It provides detailed internal views of organs, bones, and soft tissues in the body, allowing physicians to diagnose and treat medical conditions.

A ranula is a type of mucocele, which is a mucus-containing cyst that forms in the mouth. Specifically, a ranula is a mucocele that develops in the floor of the mouth, usually as a result of a blocked salivary gland duct. It appears as a smooth, dome-shaped swelling that is bluish or transparent in color. Ranulas can cause discomfort, particularly when speaking, eating, or swallowing, and they may interfere with normal oral function if they become large enough. Treatment typically involves surgical removal of the cyst, along with any affected salivary gland tissue.

Lymphatic abnormalities refer to conditions or defects that affect the lymphatic system, which is a part of the immune and circulatory systems. The lymphatic system includes a network of vessels, tissues, and organs that help rid the body of waste and toxins, fight infections, and maintain fluid balance.

Lymphatic abnormalities can occur due to genetic mutations, infections, inflammation, or cancer. These abnormalities may affect various components of the lymphatic system, including:

1. Lymph vessels: Abnormalities in lymph vessels can lead to a buildup of lymph fluid in certain parts of the body, causing swelling known as lymphedema.
2. Lymph nodes: Enlarged or abnormally shaped lymph nodes (lymphadenopathy) may indicate an infection, inflammation, or cancer.
3. Spleen: An enlarged spleen (splenomegaly) can be a sign of various conditions, such as infections, blood disorders, or cancer.
4. Thymus: Abnormalities in the thymus gland, which is part of the immune system, can lead to immunodeficiency disorders.
5. Tonsils and adenoids: Enlarged tonsils and adenoids can cause breathing and swallowing difficulties, especially in children.
6. Aggregated lymphatic tissue: Abnormalities in aggregated lymphatic tissue, such as Peyer's patches in the small intestine or the appendix, can increase the risk of infections and autoimmune disorders.

Lymphatic abnormalities can present with various symptoms, including swelling, pain, recurrent infections, and fatigue. Treatment depends on the underlying cause and may involve medications, surgery, or lifestyle changes.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

The lymphatic system is a complex network of organs, tissues, vessels, and cells that work together to defend the body against infectious diseases and also play a crucial role in the immune system. It is made up of:

1. Lymphoid Organs: These include the spleen, thymus, lymph nodes, tonsils, adenoids, and Peyer's patches (in the intestines). They produce and mature immune cells.

2. Lymphatic Vessels: These are thin tubes that carry clear fluid called lymph towards the heart.

3. Lymph: This is a clear-to-white fluid that contains white blood cells, mainly lymphocytes, which help fight infections.

4. Other tissues and cells: These include bone marrow where immune cells are produced, and lymphocytes (T cells and B cells) which are types of white blood cells that help protect the body from infection and disease.

The primary function of the lymphatic system is to transport lymph throughout the body, collecting waste products, bacteria, viruses, and other foreign substances from the tissues, and filtering them out through the lymph nodes. The lymphatic system also helps in the absorption of fats and fat-soluble vitamins from food in the digestive tract.

A subdural effusion is an abnormal accumulation of fluid in the potential space between the dura mater (the outermost layer of the meninges that covers the brain and spinal cord) and the arachnoid membrane (one of the three layers of the meninges that surround the brain and spinal cord) in the subdural space.

Subdural effusions can occur due to various reasons, including head trauma, infection, or complications from neurosurgical procedures. The fluid accumulation may result from bleeding (subdural hematoma), inflammation, or increased cerebrospinal fluid pressure. Depending on the underlying cause and the amount of fluid accumulated, subdural effusions can cause various symptoms, such as headaches, altered mental status, or neurological deficits.

Subdural effusions are often asymptomatic and may resolve independently; however, in some cases, medical intervention might be necessary to alleviate the pressure on the brain or address the underlying condition. Imaging techniques like computed tomography (CT) or magnetic resonance imaging (MRI) scans are typically used to diagnose and monitor subdural effusions.