mart-1-antigen and Gastrointestinal-Stromal-Tumors

Topics: Adult; Biomarkers, Tumor; Calmodulin-Binding Proteins; Diagnosis, Differential; Gastrointestinal Neoplasms; Gastrointestinal Stromal Tumors; High-Throughput Nucleotide Sequencing; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Keratins; Male; MART-1 Antigen; Melanoma; Middle Aged; Neoplasm Recurrence, Local; Neuroectodermal Tumors; RNA-Binding Proteins; S100 Proteins; Sarcoma, Ewing; SOXE Transcription Factors; Synaptophysin

We present a case of perivascular epithelioid cell tumor (PEComa), which clinically and histologically mimics a gastrointestinal stromal tumor (GIST).. A 42-year-old woman was found to have a mass in the left flank during her annual medical checkup. Computed tomography examination revealed a submucosal tumor of the descending colon. Surgeons and radiologists suspected that the lesion was a GIST, and left hemicolectomy was performed without biopsy. Microscopic examination showed that the lesion was composed of spindle and epithelioid cells, which were immunohistochemically negative for c-kit and positive for platelet-derived growth factor receptor (PDGFR) α. Initial diagnosis of PDGFRα-positive GIST was made. However, gene analysis did not reveal mutations in PDGFRα. Additional immunohistochemistry showed that tumor cells were positive for human melanin black 45 (HMB45), melanA, and the myogenic marker calponin. A final diagnosis of PEComa was made.. PEComa should be included in the differential diagnosis of PDGFRα-positive spindle cell tumors in the wall of the gastrointestinal tract.

Topics: Adult; Biopsy; Calcium-Binding Proteins; Calponins; Colectomy; Colon, Descending; Colonic Neoplasms; Diagnosis, Differential; Female; Gastrointestinal Stromal Tumors; Humans; Immunohistochemistry; MART-1 Antigen; Microfilament Proteins; Mutation; Perivascular Epithelioid Cell Neoplasms; Positron-Emission Tomography; Proto-Oncogene Proteins c-kit; Receptor, Platelet-Derived Growth Factor alpha; Tomography, X-Ray Computed

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

Topics: Actins; Adolescent; Adult; Aged; Carcinoma, Renal Cell; Desmin; Diagnosis, Differential; Female; Gastrointestinal Stromal Tumors; gp100 Melanoma Antigen; Humans; Immunohistochemistry; Kidney Neoplasms; Leiomyosarcoma; Male; MART-1 Antigen; Melanoma; Melanoma-Specific Antigens; Middle Aged; Perivascular Epithelioid Cell Neoplasms; S100 Proteins; Urinary Bladder Neoplasms; Young Adult

Most gastric gastrointestinal stromal tumors (GISTs) express CD117/c-kit, as do a subset of metastatic melanomas, leading to a diagnostic dilemma in some cases.. To further differentiate GISTs from melanoma, we investigated expression of melanoma markers in GISTs using a well-characterized set of gastric lesions on tissue microarrays.. Tissue microarrays from paraffin-embedded tissue cores from 38 patients were stained with S100 protein, HMB-45, and Melan-A antibodies. All cases had been previously stained with CD117/c-kit and CD34 antibodies. All were reactive with CD117/c-kit, and 88.2% expressed CD34.. S100 protein was focally expressed in 2 (5.3%) of 38 GISTs; these lesions lacked HMB-45 and Melan-A labeling. No tumor labeled with HMB-45, but 4 (10.6%) of 38 cases labeled with Melan-A antibodies. The Melan-A-reactive cases were all S100 negative and CD34 positive. The S100-reactive cases were spindle cell neoplasms, whereas the Melan-A-reactive cases were epithelioid neoplasms (4/9; 44%). An additional 15 standard sections of separate cases of epithelioid GISTs were then labeled with Melan-A, and 5 (33%) of 15 showed at least focal labeling.. Melan-A staining can be encountered in a subset of epithelioid GISTs, a finding that can suggest a differential diagnosis of melanoma. In this series, the Melan-A-reactive cases lacked S100 protein and expressed CD34, both of which would be unlikely in melanoma. As such, a panel approach is best in differentiating epithelioid GISTs from melanoma.

Topics: Adult; Aged; Aged, 80 and over; Antigens, CD34; Antigens, Neoplasm; Biomarkers, Tumor; Diagnosis, Differential; Female; Gastrointestinal Stromal Tumors; Humans; Male; MART-1 Antigen; Melanoma; Melanoma-Specific Antigens; Microarray Analysis; Middle Aged; Neoplasm Proteins; S100 Proteins

Topics: Adult; Antigens, Neoplasm; Gastrointestinal Neoplasms; Gastrointestinal Stromal Tumors; Humans; Male; MART-1 Antigen; Neoplasm Proteins; Osteoclasts; S100 Proteins; Sarcoma, Clear Cell; Soft Tissue Neoplasms