mart-1-antigen and Neurofibroma

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

Topics: Adult; Aged; Antigens, CD34; Child, Preschool; Dermatofibrosarcoma; Diagnosis, Differential; Female; Follow-Up Studies; gp100 Melanoma Antigen; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Male; MART-1 Antigen; Melanoma; Melanoma-Specific Antigens; Middle Aged; Neoplasm Recurrence, Local; Neurilemmoma; Neurofibroma; Oncogene Proteins, Fusion; Prognosis; Retrospective Studies; S100 Proteins; Skin Neoplasms; Vimentin

Neurotized melanocytic nevi and neurofibromas are common, benign cutaneous neoplasms. Usually they are histologically distinct from each other; however, neurotized melanocytic nevi and neurofibromas can be clinically and histologically similar.. To determine whether Melan-A (MART-1) immunohistochemical stain is sufficient to differentiate neurotized melanocytic nevi from neurofibromas.. Forty-nine consecutive specimens of melanocytic nevi with neurotization and 49 specimens of neurofibromas were selected. We used antibodies against Melan-A, S100, and neurofilament protein.. All of the melanocytic nevi showed Melan-A staining within the neurotized areas, with most of the areas staining strongly positive, whereas all the neurofibromas were completely absent of Melan-A stain. All of the nevi, including the neurotized areas, stained strongly and diffusely for S100, whereas all the neurofibromas showed a distinctive, sharp, wavy pattern of S100 staining. Neurofilament protein showed scattered staining of both melanocytic nevi and neurofibromas.. Our data indicate that Melan-A immunohistochemical staining is helpful in differentiating neurotized melanocytic nevi from neurofibromas when distinction on histomorphology alone is difficult.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Male; MART-1 Antigen; Middle Aged; Neurofibroma; Nevus, Pigmented; Skin Neoplasms