General term for the abnormal appearance of histiocytes in the blood. Based on the pathological features of the cells involved rather than on clinical findings, the histiocytic diseases are subdivided into three groups: HISTIOCYTOSIS, LANGERHANS CELL; HISTIOCYTOSIS, NON-LANGERHANS-CELL; and HISTIOCYTIC DISORDERS, MALIGNANT.

Distinctive neoplastic disorders of histiocytes. Included are malignant neoplasms of MACROPHAGES and DENDRITIC CELLS.

Malignant neoplasms composed of MACROPHAGES or DENDRITIC CELLS. Most histiocytic sarcomas present as localized tumor masses without a leukemic phase. Though the biological behavior of these neoplasms resemble lymphomas, their cell lineage is histiocytic not lymphoid.

A rare form of non-Langerhans-cell histiocytosis (HISTIOCYTOSIS, NON-LANGERHANS-CELL) with onset in middle age. The systemic disease is characterized by infiltration of lipid-laden macrophages, multinucleated giant cells, an inflammatory infiltrate of lymphocytes and histiocytes in the bone marrow, and a generalized sclerosis of the long bones.

A major affective disorder marked by severe mood swings (manic or major depressive episodes) and a tendency to remission and recurrence.

Psychiatric illness or diseases manifested by breakdowns in the adaptational process expressed primarily as abnormalities of thought, feeling, and behavior producing either distress or impairment of function.

Persistent and disabling ANXIETY.

Those disorders that have a disturbance in mood as their predominant feature.

Categorical classification of MENTAL DISORDERS based on criteria sets with defining features. It is produced by the American Psychiatric Association. (DSM-IV, page xxii)

Marked depression appearing in the involution period and characterized by hallucinations, delusions, paranoia, and agitation.