OBJECTIVETo study the pathologic features and immunophenotype of 3 cases of melanotic epithelioid clear cell tumor of kidney.

METHODSMore than 2000 cases of renal tumors were retrospectively reviewed. Three cases of melanotic epithelioid clear cell tumor were identified. Immunohistochemical study was carried out using the paraffin-embedded tissue samples. Electron microscopy was also performed in 1 case.

RESULTSAmongst the 3 cases studied, the male-to-female ratio is 1:2. Histologically, 2 cases showed a clear cell carcinoma-like pattern. Papillary structures covered by clear cells and eosinophilic cells were observed in 1 case. Immunohistochemical study showed that the tumor cells in all cases expressed HMB 45. Two of them were also positive for Melan A. The staining for epithelial markers and S-100 protein was negative. Melanosomes were not identified by ultrastructural examination.

CONCLUSIONSMelanotic epithelioid clear cell tumor is a rarely seen neoplasm of kidney. There are some histologic overlaps with renal cell carcinoma, epithelioid angiomyolipoma and melanoma. Immunohistochemical study is useful in confirming the diagnosis. The tumor represents a morphologic variant of epithelioid angiomyolipoma.

Adolescent ; Adult ; Angiomyolipoma ; metabolism ; pathology ; surgery ; Carcinoma, Renal Cell ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Epithelioid Cells ; metabolism ; pathology ; Female ; Follow-Up Studies ; Humans ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; MART-1 Antigen ; metabolism ; Male ; Melanoma-Specific Antigens ; metabolism ; Retrospective Studies

Adult ; Angiomyolipoma ; metabolism ; pathology ; surgery ; Carcinoma, Renal Cell ; metabolism ; pathology ; Diagnosis, Differential ; Humans ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; MART-1 Antigen ; metabolism ; Male ; Melanoma-Specific Antigens ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo study the clinicopathologic features and differential diagnosis of cutaneous regressing/regressed melanoma.

METHODSHistopathologic evaluation and immunohistochemical study by EnVision method were performed in 8 cases of cutaneous regressing/regressed melanoma. The clinical presentation, treatment and follow-up data were analyzed.

RESULTSThe age of the patients ranged from 40 to 69 years (mean 58 years). The male-to-female ratio was 3: 1. Tumors were located on the back (4 cases), sole of the foot (2 cases), ventral aspect of the toes (1 case), and the forearm (1 case). Clinically, 6 patients presented with progressive black mole of the skin, followed by subsequent focal hypopigmentation, even scarring. Two patients presented with multiple foci of dark-brown pigmentation. Microscopically, 3 cases were completely regressed malignant melanoma. Tumoral melanosis was found in 1 of 3 cases. The other 5 cases were melanoma with severe regression. The extent of regression ranged from 75% to 90%. The Breslow depth of the tumors ranged from 0.5 to 1.0 mm. Immunohistochemically, both metastatic and primary tumor cells were diffusely positive for S-100, HMB45 and Melan A, while melanophages were positive for CD68. Follow-up data were available in 8 patients, ranging from 8 to 27 months. Five patients were alive with no evidence of disease, 1 patient was alive with stable disease and 2 patients died of metastatic melanoma.

CONCLUSIONSCorrelation between clinical presentation and pathologic features is important for diagnosis of cutaneous regressing/regressed melanoma. Thin melanoma with extensive regression ( ≥ 75%) should not been regarded as low metastatic risk and wide excision combined with sentinel lymph node biopsy is recommended.

Adult ; Aged ; Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Back ; pathology ; Female ; Follow-Up Studies ; Foot ; pathology ; Humans ; Lymphatic Metastasis ; MART-1 Antigen ; metabolism ; Male ; Melanoma ; metabolism ; pathology ; surgery ; Melanoma-Specific Antigens ; metabolism ; Melanosis ; pathology ; Middle Aged ; S100 Proteins ; metabolism ; Sentinel Lymph Node Biopsy ; Skin Neoplasms ; metabolism ; pathology ; surgery ; Toes ; pathology ; Treatment Outcome

OBJECTIVETo investigate the clinical pathological features, diagnosis and differential diagnosis of pigmented dermatofibrosarcoma protuberance (PDFSP).

METHODSThe clinical history, histopathological features, immunohistochemical characteristics, treatment and prognosis were analyzed in seven cases of PDFSP. Fluorescence in situ hybridization (FISH) was used to detect the expression of COL1A1/PDGFB fusion gene, and related literature was reviewed.

RESULTSThe median age of the seven patients (4 females, 3 males) was 47 years with the tumors involving mostly the trunk (four cases). Histologically, PDFSP showed a cellular lesion composed of spindle cells arranged in short fascicles that form a distinct storiform pattern, and the pigmented bipolar or multipolar dendritic cells were present with tentacle like processes emanating from a nucleus containing zone. One case showed fibrosarcomatous change. The pigment was tinctorially similar to melanin. The spindle cells were positive for CD34 and vimentin, but negative for HMB45, Melan A, S-100, desmin, CD68 or α-SMA. HMB45, Melan A, S-100 and vimentin were expressed in the melanin containing cells in 4, 4, 5 and 7 cases, respectively. The labeling index of Ki-67 was 1%-8%. Among the 4 cases successfully examined by FISH, 3 showed t(17;22)(q21;q13) which suggested COL1A1/PDGFB fusion gene. Three patients were treated by wide local excision and four were treated by simple surgical excision. Two patients developed recurrences during the follow-up period of 12 to 123 months. Of those treated by wide local excision, none developed recurrence. No patient died in the follow-up period.

CONCLUSIONSPDFSP is a rare pigmented variant of DFSP and an intermediate grade malignant tumor. The orgin of the tumor cells is still controversial. Surgical pathologists and dermatopathologists need to be aware of the prototypical histological appearance of PDFSP as there is a risk of misdiagonsing it as either pigmented tumors associated with neurocutaneous syndromes or a highly malignant melanocytic neoplasm.

Adult ; Aged ; Antigens, CD34 ; metabolism ; Child, Preschool ; Dermatofibrosarcoma ; diagnosis ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Immunohistochemistry ; In Situ Hybridization, Fluorescence ; MART-1 Antigen ; metabolism ; Male ; Melanoma ; metabolism ; pathology ; Melanoma-Specific Antigens ; metabolism ; Middle Aged ; Neoplasm Recurrence, Local ; Neurilemmoma ; metabolism ; pathology ; Neurofibroma ; metabolism ; pathology ; Oncogene Proteins, Fusion ; metabolism ; Prognosis ; Retrospective Studies ; S100 Proteins ; metabolism ; Skin Neoplasms ; diagnosis ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

Adolescent ; Carcinoma, Renal Cell ; metabolism ; pathology ; Desmin ; metabolism ; Diagnosis, Differential ; Humans ; Leg ; MART-1 Antigen ; metabolism ; Male ; Melanoma ; metabolism ; pathology ; Melanoma-Specific Antigens ; metabolism ; Perivascular Epithelioid Cell Neoplasms ; metabolism ; pathology ; surgery ; Sarcoma, Clear Cell ; metabolism ; pathology ; Skin Neoplasms ; metabolism ; pathology ; surgery

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

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

OBJECTIVETo study the clinicopathologic features, immunophenotype and genetic changes of perivascular epithelioid cell neoplasms (PEComa).

METHODSA total of 25 cases of PEComa located in various anatomic sites were selected for immunohistochemical staining (SP or EnVision method). TFE3 fluorescence in-situ hybridization was also performed to determine the TFE3 gene status.

RESULTSThe age of patient ranged from 21 to 61 years (mean = 43 years). The male-to-female ratio was 1: 1.3. Histologically, 22 cases represented conventional angiomyolipomas, composed of a mixture of adipose tissue, spindle element, epithelioid smooth muscle cells and abnormal thick-walled blood vessels in various proportions. Three cases involving lung, soft tissue and broad ligament had subtle but distinctive morphologic features. Nested or sheet-like architecture with epithelioid or spindle cells was observed. Immunohistochemical study showed that HMB 45, melan A, smooth muscle actin and cathepsin K were expressed in 80% (20/25), 88% (22/25), 88% (22/25) and 100% (25/25) of PEComa, respectively. Within positive cases, the average proportion of positive tumor cells was 36%, 41%, 35% and 90% respectively for HMB 45, melan A, smooth muscle actin and cathepsin K. TFE3 was negative in all of the 22 renal and hepatic PEComa studied, while it was positive in the 3 cases of extra-hepatorenal PEComa. None of the 25 cases exhibited evidence of TFE3 gene fusion or amplification.

CONCLUSIONSExtra-hepatorenal PEComa have distinctive morphologic features and are associated with TFE3 overexpression. Cathepsin K immunostaining demonstrates high sensitivity and specificity in PEComa, better than other commonly employed immunomarkers. This marker is thus useful in diagnosis of PEComa and distinction with other neoplasms.

Actins ; metabolism ; Adult ; Angiomyolipoma ; metabolism ; pathology ; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors ; genetics ; metabolism ; Cathepsin K ; metabolism ; Female ; Humans ; Immunohistochemistry ; Kidney Neoplasms ; metabolism ; pathology ; Liver Neoplasms ; metabolism ; pathology ; MART-1 Antigen ; metabolism ; Male ; Melanoma-Specific Antigens ; metabolism ; Middle Aged ; Perivascular Epithelioid Cell Neoplasms ; metabolism ; pathology ; Young Adult

OBJECTIVETo study the clinicopathologic features, immunophenotype, histological diagnosis and prognosis of hepatic epithelioid angiomyolipoma.

METHODSClinical data of 25 cases of hepatic epithelioid angiomyolipoma were collected along with follow-up study of the patients. The pathological features were documented and immunohistochemical study of various markers was performed with an emphasis on diagnosis and differential diagnosis.

RESULTSHepatic epithelioid angiomyolipoma was more commonly found in young women without characteristic clinical symptoms. Its morphological features were characterized by marked cytological atypia, relatively rare mitotic figures; radial distribution of tumor cells around the thin-walled blood vessels or muscular vessels; and the presence of common multinucleated giant cells and large ganglion-like tumor cells. The tumor cells expressed both melanoma cell markers (HMB45, MART-1) and smooth muscle cell markers (SMA). Tumor cells expressed various other markers including ER 16% (4/25), PR 32% (8/25), TFE3 24% (6/25) and p53 60% (15/25).

CONCLUSIONSHepatic epithelioid angiomyolipoma has variable morphological features and characteristic immunohistochemical phenotype. The differential diagnoses include a variety of tumors. The biological behavior of the tumor tends to be benign.

Age Factors ; Angiomyolipoma ; genetics ; immunology ; metabolism ; pathology ; Biomarkers, Tumor ; metabolism ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Gastrointestinal Neoplasms ; Giant Cells ; pathology ; Humans ; Immunohistochemistry ; Immunophenotyping ; Liver Neoplasms ; genetics ; immunology ; metabolism ; pathology ; MART-1 Antigen ; metabolism ; Melanoma-Specific Antigens ; metabolism ; Muscle, Smooth ; metabolism ; Prognosis

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