RESUMO
The formation of structures resembling hair matrices is the least common form of follicular differentiation and only occurs with any frequency in pilomatricoma. Rarely, follicular cysts and both benign and malignant adnexal tumors can show areas of pilomatricoma-like change, or hair matrix differentiation. Examples of focal hair matrix differentiation in a follicular cyst, a cutaneous mixed tumor, and an adnexal carcinoma are presented. Each of these cases also demonstrates the presence of limited differentiation toward structures of the inner root sheath.
Assuntos
Cisto Epidérmico/ultraestrutura , Cisto Folicular/ultraestrutura , Cabelo/ultraestrutura , Neoplasias Cutâneas/ultraestrutura , Adulto , Idoso , Cisto Epidérmico/epidemiologia , Cisto Folicular/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Cutâneas/epidemiologiaRESUMO
A 46-year-old man presented with an unusual angiosarcoma of skin and urinary bladder, clinically suggestive of Kaposi's sarcoma (KS). Histologically, the pattern was that of an anaplastic angiosarcoma with only minimal regions considered characteristic of KS. It is suggested that this rare type of angiosarcoma may be closely related to, if not best classified as, an anaplastic variant of KS. The cutaneous lesions responded to intralesional vinblastine. The association of anaplastic angiosarcoma with homosexual sexual practices should be investigated along with those cases having the classical histologic characteristics of Kaposi's sarcoma.
Assuntos
Hemangiossarcoma/diagnóstico , Homossexualidade , Sarcoma de Kaposi/diagnóstico , Neoplasias Cutâneas/diagnóstico , Diagnóstico Diferencial , Hemangiossarcoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Sarcoma de Kaposi/patologia , Neoplasias Cutâneas/patologia , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/patologiaRESUMO
An unusual case of cavernous hemangioma of the superior mediastinum in a 38-year-old male is presented. Mediastinal hemangiomas occur more often in children and are usually localized in the anterior-superior compartment in all age groups. Slow expansile growth, lack of infiltration of adjacent structures and microscopically mature cellular elements clearly marked the benign nature of the lesion. Vascular mesenchymal tumors in this location must be approached with caution because of the risks of hemorrhage or local infiltration of vital structures. Electron microscopy revealed active endothelial cells, smooth muscle cells, and intercellular matrix components suggestive of smooth muscle cell origin. Computerized tomography delineated the lesion clearly and demonstrated identical densities for the mass and adjacent blood vessels.
