"Mesenchymal tumor" or "decidual-like reaction"?
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For more than 40 yr, an unusual urinary bladder lesion has been known to occur in certain strains of mice, but no consensus has been obtained regarding its etiology, pathogenesis, biology, or classification. The lesion was first assumed to be epithelial and non-neoplastic, then it was called a smooth muscle cell tumor or leiomyosarcoma because of ultrastructural characteristics for smooth muscle cells. Later, the nonspecific term "mesenchymal tumor" was introduced due to histomorphologic differences from all smooth muscle tumors known. Recently, a proposal was made to name it "decidual-like reaction" because of the histomorphologic similarity to the rare spontaneous decidual reaction in the uterus of aging mice. Both lesions are characterized by spindle and large pleomorphic epithelioid cells with large bizarre nuclei; these characteristics mimic anaplasia of malignant tumors and led pathologists to assume a neoplastic nature. The decidual hypothesis is supported by the regular presence of nuclear progesterone receptors, the occasional occurrence of eosinophilic cytoplasmic granules, the rare finding of cells morphologically resembling granulated metrial gland cells (all also observed in the uterine decidual reaction), and the reproducibility through long-term feeding of combinations of estrogens and progestogens. It appears that the new decidual hypothesis can explain many detailed facets of the lesion, with the exception of the reported smooth muscle cell characteristics. The controversy of "mesenchymal tumor versus decidual-like reaction" should be resolved soon, not only as a scientific issue, but also because of consequences for risk assessment. (+info)
Retinol esterification activity contributes to retinol transport in stellate cells.
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The mechanisms of retinol transport and accumulation in hepatic stellate cells (HSC) remain to be elucidated. Our previous studies suggested that retinol esterification activity, particularly lecithin:retinol acyltransferase (LRAT) activity, in liver retinoid metabolism is important to elucidate the relationship between retinol uptake by HSC and the esterification of retinol. In the present study, using a human HSC-like cell line, LI90, we demonstrated that retinol esterification activity of LI90 cells is similar to that of primary cultures of rat HSC and higher than that of a human hepatoma cell line. Further, since progesterone or diphospho-lauroyl-phosphatidylcholine increased retinol esterification activity of LI90 cells, it is likely that LRAT contributes to retinol esterification in LI90. We examined retinol esterification in LI90 cells and clearance of retinol from culture medium. The percentages of both retinol and esterified retinol in LI90 cells increased in a manner dependent on retinol concentration in medium, whereas that of retinol in medium decreased. The percentages of esterified and unesterified retinol in LI90 cells and of retinol in medium were linearly dependent on the logarithm of the initial concentration of retinol in the medium. These results suggest that retinol esterification activity contributes to retinol uptake by HSC and maintenance of non-toxic retinol levels in plasma. (+info)
Oesophageal mesenchymal tumours: clinicopathological features and absence of Epstein-Barr virus.
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BACKGROUND: Recent studies have suggested that the Epstein-Barr virus (EBV) is associated with smooth muscle tumours (leiomyoma and leiomyosarcoma) in patients with human immunodeficiency virus and in organ transplant recipients. Leiomyoma is the most common mensenchymal tumour found in the oesophagus. AIM: To report a single institution experience on oesophageal mesenchymal tumours and to determine whether EBV is associated with these tumours. METHODS: 40 sporadic oesophageal mesenchymal tumours were studied and their diagnosis confirmed on pathological review and immunohistochemical studies. Formalin fixed, paraffin was embedded tissues from these tumours were analysed for EBV using in situ hybridisation for two messenger RNA (mRNA) probes, EBER and BamH1 W. RESULTS: The oesophageal mesenchymal tumours comprised 36 leiomyomas, two undifferentiated stromal tumours, and two gastrointestinal autonomic nerve tumours (GANTs). Median age of the patients with leiomyoma (26 men, 10 women) was 62 years (range 30 to 85) and 81% of them had an asymptomatic lesion. The median longitudinal size was 1.2 cm. Multiple leiomyomas were seen in 11% of the patients and calcification was noted in one tumour. Coexisting squamous cell carcinoma was found in one third of cases. The stromal tumours were small, asymptomatic, and located in the lower third of the oesophagus, while the GANTs were large, symptomatic, and found in the upper third of the oesophagus. EBV mRNAs were not detected in all these tumours. CONCLUSIONS: The clinicopathological features of oesophageal leiomyoma, undifferentiated stromal tumour, and GANT were different. Some oesophageal leiomyomas were associated with oesophageal squamous cell carcinomas. EBV is not associated with sporadic oesophageal mesenchymal tumours. (+info)
Outcome in patients with adrenal incidentaloma selected for surgery: an analysis of 88 cases investigated in a single clinical center.
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OBJECTIVE: The study was designed to evaluate the clinical, endocrinological and radiological parameters used to investigate adrenal incidentalomas and select patients for surgery. DESIGN AND METHODS: An analysis of 88 consecutive patients with adrenal incidentaloma selected for surgery and investigated in a single clinical center was performed. RESULTS: Mean (+/-s.d.) age of the patients was 53+/-14 years. Fourteen (16%) of the adrenal incidentalomas were malignant tumors (2 adrenocortical carcinomas, 3 metastases, 4 adenocarcinomas, 4 sarcomas and 1 mesenchymoma), 10 (11%) were pheochromocytomas, 32 (36%) were non-secretory benign adrenal adenomas and the remaining were benign adrenal (n = 8; 9%) or extra-adrenal (n = 24; 27%) masses. Endocrinological investigations revealed 1 Conn adenoma, 4 tumors responsible for Cushing's syndrome or silent hypercortisolism and 1 androgen secreting tumor. Abnormalities of endocrine evaluations were observed in the 2 malignant adrenocortical carcinomas. Elevated 24-h urinary metanephrine levels were observed in the 9 pheochromocytomas tested. Complications of surgery occurred in 14% of the cases. Regardless of the endocrine status, parameters associated with malignant tumors were: older age (mean age of patients harboring malignant tumors vs patients with benign incidentalomas: 62+/-17 years vs 52+/-13 years, P = 0.005), weight loss (39% vs 7%, P = 0. 005), and mass diameter greater than 60mm (69% vs 15%, P < 0.001). By multiple logistic regression analysis malignant tumors were associated with increased age, diameter greater than 60mm and bilateral masses. CONCLUSION: This study points to a high rate of pheochromocytomas and malignant tumors in patients selected for surgery. This high rate differs from some previous reports and might be explained by the criteria used to select patients for surgery. Among these two groups of tumors, careful systematic endocrinological investigations allow the detection of altered secretion in the vast majority - if not all - malignant tumors of adrenal origin and pheochromocytomas. Only 5% of the incidentalomas below 30 mm selected for surgery in this study were malignant, in keeping with the use of this criteria as an important parameter to select patients with normal hormonal investigations for careful follow-up. (+info)
Cartilage and bone containing benign mesenchymoma of the thigh and popliteal fossa.
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We report a case of a large cartilage and bone containing mesenchymoma of the thigh and popliteal fossa in a 56-year-old man. Mesenchymomas are rare tumors with a histologically benign pattern. They may be associated with morbidity as a result of local infiltrative growth. (+info)
Gastrointestinal stromal tumors of the small intestine that expressed c-kit protein.
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We report two patients with gastrointestinal stromal tumors (GISTs) of the small intestine that expressed c-kit protein (CD117). One was a 68-year-old woman with epigastralgia and vomiting. A submucosal tumor of the upper jejunum was detected, and partial resection was carried out. The histology revealed a GIST negative for CD34 but positive for CD117. The other was a 42-year-old woman with progressive anemia, melena and lower abdominal pain. Intussusception was detected, and a partial resection was carried out. A submucosal tumor of the lower jejunum was noted. The histology revealed a GIST positive for both CD34 and CD117. (+info)
The histopathological differential diagnosis of gastrointestinal stromal tumours.
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Gastrointestinal stromal tumours (GISTs), initially presumed to be of "true" smooth muscle origin, encompass a heterogeneous, and as yet incompletely understood, group of mesenchymal tumours with respect to their origin, cellular differentiation, and prognosis. Cellular morphology ranges from predominantly spindle shaped to epithelioid in character, whereas differentiation pathways, as determined primarily by immunohistochemistry and ultrastructure, can vary from indeterminate to myoid and/or neural. Recent work has indicated that the interstitial cells of Cajal, a complex cellular network postulated to act as pacemaker cells of the gastrointestinal tract, which exhibit both myoid and neural features, could be candidates for tumour histogenesis. This would provide a plausible and attractive explanation for the variable differentiation pathways identified in the GIST category to date. Nevertheless, the occasional but undisputed location of GISTs outside the gastrointestinal tract (omentum, peritoneum, and retroperitoneum) might mitigate against such an origin, and their histogenesis remains open to debate. The c-kit proto-oncogene, encoding a growth factor receptor with tyrosine kinase activity, has been postulated to play an important role in tumorigenesis because "gain of function" mutations in this gene, localised to chromosome 4q11-21, are being increasingly identified in hereditary and sporadic cases. Monoclonal and polyclonal antibodies directed at the c-kit gene product expressed on the cell surface (CD117/c-kit) appear to be increasingly helpful in resolving the histopathological differential diagnosis between GISTs and true gastrointestinal smooth muscle neoplasms, schwannomas, and other far less frequently occurring mesenchymal tumours at this site. Although tumours with a clinically benign course appear to be more common than their malignant counterparts, no specific histological criteria have as yet been identified to enable an unambiguous prediction of biological behaviour. Increasing tumour size and mitotic activity favour aggressive tumour behaviour, whereas the prognostic value of germline and somatic mutations within the c-kit proto-oncogene remains to be elucidated further. It is the aim of this synopsis to highlight the relevant fundamental and diagnostic developments with respect to this complex group of neoplasms. (+info)
What we could do now: molecular pathology of gynaecological cancer.
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Gynaecological tumours exemplify many of the molecular paradigms of carcinogenesis. The clinical value of many of the molecular abnormalities present is now being tested and it is likely that the identification of at least some of these will become routine in the near future. This may help to refine diagnosis and guide treatment-for example, therapeutic vaccination for human papillomavirus related disease. (+info)