Esophageal Neoplasms ; metabolism ; pathology ; Female ; Humans ; Melanoma ; metabolism ; pathology ; Melanoma-Specific Antigens ; metabolism ; Middle Aged ; S100 Proteins ; metabolism

Adolescent ; Brain Neoplasms ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Humans ; Melanoma ; metabolism ; pathology ; Melanoma-Specific Antigens ; metabolism ; Neurilemmoma ; metabolism ; pathology ; S100 Proteins ; metabolism ; Vimentin ; metabolism

Adult ; Breast Neoplasms ; secondary ; Diagnosis, Differential ; Female ; Humans ; Melanoma ; metabolism ; pathology ; secondary ; Melanoma-Specific Antigens ; metabolism ; Middle Aged ; S100 Proteins ; metabolism ; Sarcoma, Clear Cell ; pathology ; Skin Neoplasms ; pathology

Aged ; Back ; Carcinoma, Medullary ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Humans ; Melanoma ; metabolism ; pathology ; secondary ; surgery ; Melanoma-Specific Antigens ; metabolism ; S100 Proteins ; metabolism ; Skin Neoplasms ; metabolism ; pathology ; surgery ; Thyroid Neoplasms ; metabolism ; pathology ; secondary ; surgery

OBJECTIVETo investigate the mode of angiogenesis between highly invasive malignant melanoma and poorly invasive malignant melanoma by immunohistochemistry and periodic acid-Schiff stain (PAS) and to discuss whether the tumor cells in highly invasive malignant melanoma carry vasculogenic mimicry through self-metamorphosis, thus acquiring blood supply to sustain their growth.

METHODSThirty cases of highly invasive malignant melanoma and 30 cases of poorly invasive malignant melanoma were retrieved and reprocessed as tissue microarray for further investigations. The tissue microarray sections were then stained with CD34 and PAS; and the positivity rates were compared.

RESULTSThere was a significant difference between CD34 and PAS staining in highly invasive malignant melanoma (P < 0.01). The difference was not statistically significant in poorly invasive malignant melanoma (P > 0.05).

CONCLUSIONVasculogenic mimicry exists in some cases of highly invasive malignant melanoma. It is possible that the tumor cells can acquire blood supply to sustain growth and metastasize via this mechanism.

Antigens, CD34 ; analysis ; Antigens, Neoplasm ; Humans ; Immunohistochemistry ; Keratins ; analysis ; Melanoma ; blood supply ; metabolism ; pathology ; Melanoma-Specific Antigens ; Neoplasm Proteins ; analysis ; Neovascularization, Pathologic ; metabolism ; pathology

Adult ; Diagnosis, Differential ; Humans ; MART-1 Antigen ; metabolism ; Magnetic Resonance Imaging ; Male ; Medulloblastoma ; metabolism ; pathology ; Melanocytes ; pathology ; Melanoma ; diagnosis ; metabolism ; pathology ; surgery ; Melanoma-Specific Antigens ; metabolism ; Meningeal Neoplasms ; diagnosis ; metabolism ; pathology ; surgery ; Neoplasms, Multiple Primary ; diagnosis ; metabolism ; pathology ; surgery ; Neurilemmoma ; metabolism ; pathology ; Nevus of Ota ; diagnosis ; metabolism ; pathology ; surgery ; S100 Proteins ; metabolism ; Skin Neoplasms ; diagnosis ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

Actins ; metabolism ; Adenocarcinoma, Clear Cell ; metabolism ; pathology ; Adult ; Carcinoma, Renal Cell ; metabolism ; pathology ; Desmin ; metabolism ; Diagnosis, Differential ; Endometrial Stromal Tumors ; metabolism ; pathology ; Female ; Follow-Up Studies ; Humans ; Hysterectomy ; Leiomyoma, Epithelioid ; metabolism ; pathology ; Melanoma ; metabolism ; pathology ; Melanoma-Specific Antigens ; metabolism ; Perivascular Epithelioid Cell Neoplasms ; metabolism ; pathology ; surgery ; Receptors, Progesterone ; metabolism ; Uterine Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

OBJECTIVETo study the clinicopathologic features and differential diagnosis of perivascular epithelioid cell tumors (PEComas) occurring in the urinary system.

METHODSThe clinicopathologic features of 21 cases of PEComa from September 2002 to September 2010 occurring in the urinary system were retrospectively reviewed. Immunohistochemical study for HMB 45, S-100 protein, smooth muscle actin, desmin, Melan A and Ki-67 was carried out.

RESULTSAmongst the 21 cases studied, there were 5 males and 16 females. The age of patients ranged from 16 to 76 years (median = 51.3 years). Twenty cases occurred in the kidney and 1 in the bladder. The predominant histopathologic subtype of renal PEComas was classic type (10/20), followed by epithelioid type (5/20), smooth muscle type (3/20), inflammatory type (1/20) and sclerosing type (1/20). Immunohistochemical study showed that HMB 45 and smooth muscle actin were positive in 95.2% (20/21) and 80.9% (17/21) cases, respectively. Melan A, desmin and S-100 protein were expressed in 71.4% (15/21), 61.9% (13/21) and 33.3% (7/21) cases, respectively. The mean proliferative index was 1.29% (range = 0 to 5%). HMB 45 and Melan A were expressed in all of the 5 cases of epithelioid PEComas, whereas smooth muscle actin and desmin were only expressed in one of them. There was no significant difference between epithelioid PEComas and non-epithelioid PEComas in the expression of HMB 45, Melan A, smooth muscle actin and desmin. Positive staining for HMB 45 and smooth muscle actin was demonstrated in the case of bladder PEComa.

CONCLUSIONSPEComas of the urinary system predominantly affect the kidney. Epithelioid renal PEComas and bladder PEComa are relatively rare and have unique pathologic features. It is necessary to distinguish PEComas from other malignant tumors. Immunohistochemical study for HMB 45, Melan A and smooth muscle actin is helpful for confirmation of diagnosis.

Actins ; metabolism ; Adolescent ; Adult ; Aged ; Carcinoma, Renal Cell ; metabolism ; pathology ; Desmin ; metabolism ; Diagnosis, Differential ; Female ; Gastrointestinal Stromal Tumors ; metabolism ; pathology ; Humans ; Immunohistochemistry ; Kidney Neoplasms ; metabolism ; pathology ; Leiomyosarcoma ; metabolism ; pathology ; MART-1 Antigen ; metabolism ; Male ; Melanoma ; metabolism ; pathology ; Melanoma-Specific Antigens ; metabolism ; Middle Aged ; Perivascular Epithelioid Cell Neoplasms ; metabolism ; pathology ; S100 Proteins ; metabolism ; Urinary Bladder Neoplasms ; metabolism ; pathology ; Young Adult

Abdominal Neoplasms ; metabolism ; pathology ; Adolescent ; Diagnosis, Differential ; Fibroblasts ; metabolism ; pathology ; Groin ; Histiocytoma, Malignant Fibrous ; metabolism ; pathology ; Humans ; Keratins ; metabolism ; Lymph Nodes ; metabolism ; pathology ; Lymphoma ; metabolism ; pathology ; Male ; Melanoma ; metabolism ; pathology ; Vimentin ; metabolism

Actins ; metabolism ; Angiomyolipoma ; pathology ; Carcinoma, Renal Cell ; pathology ; Diagnosis, Differential ; Epithelioid Cells ; metabolism ; pathology ; Female ; Gastrointestinal Neoplasms ; pathology ; Gastrointestinal Stromal Tumors ; pathology ; Humans ; Kidney Neoplasms ; metabolism ; pathology ; Lung Neoplasms ; pathology ; Lymphangioleiomyomatosis ; pathology ; Male ; Melanoma ; pathology ; Melanoma-Specific Antigens ; metabolism ; Pancreatic Neoplasms ; pathology ; Perivascular Epithelioid Cell Neoplasms ; metabolism ; pathology ; Sarcoma, Clear Cell ; pathology ; Skin Neoplasms ; pathology ; Uterine Neoplasms ; pathology