Superficial CD34-Positive Fibroblastic Tumor

Superficial CD34-positive fibroblastic tumor (SCPFT) is a recently described entity that, despite significant pleomorphism, carries a good prognosis. We briefly describe this tumor and its principal differential diagnoses. Recognition of SCPFTs, including the clinical context in which they arise, is important to avoid confusion with other pleomorphic soft tissue tumors, particularly neoplasms in the group of pleomorphic sarcomas, which are typically aggressive tumors that could lead to unnecessary overtreatment.

Superficial CD34-positive fibroblastic tumor in the forearm of a middle-aged patient: A newly described, rare soft-tissue tumor

Superficial CD34-positive fibroblastic tumor is a recently described soft-tissue tumor entity. A 48 year-old-male presented with a gradually increasing soft-tissue mass in his right forearm of 2 years' duration, along with multiple subcutaneous soft-tissue nodular lesions, and reminiscent of lipomas over his body. He underwent a wide excision of his forearm mass. Microscopic sections showed a circumscribed tumor in the dermis and subcutaneous fat, composed of spindle cells, inflammatory cells, including lymphocytes, plasma cells, and eosinophils, along with interspersed markedly pleomorphic giant cells containing moderate-to-abundant "glassy" cytoplasm, vesicular nuclei, exhibiting prominent nucleoli, and intranuclear pseudoinclusions. There were no significant mitotic figures, areas of hemorrhage, necrosis, or pigment histiocytes. By immunohistochemistry, the tumor cells were diffusely positive for CD34 while negative for cytokeratin (CK), pan CK (AE1/AE3), S100 protein, CD30, and CD31. MIB1/Ki-67 was low and highlighted 4%-5% tumor nuclei. Diagnosis of superficial CD34-positive fibroblastic tumor was offered. Sections from the various resection margins were free of tumor. Postresection, the patient is alive with no evidence of disease for the past 8 months. This constitutes as one of the first case reports of this rare tumor entity from our country. Its diagnostic and treatment implications are discussed herewith.

Superficial CD34-positive fibroblastic tumor: A new case from Japan

A 48-year-old Japanese woman presented with a painless, slow-growing, brown nodule of 15 mm in diameter on the left thigh. She noticed the nodule a few years before the first presentation to our hospital. She underwent total resection of the nodule. On histopathological examination, a relatively well-defined tumor with infiltrative growth was located in the dermis and extended into the subcutis. The tumor was composed of spindle to polygonal cells with pleomorphic nuclei arranged in a sheet-like or fascicular pattern. Tumor cells with granular cytoplasm were also scattered. Immunohistochemical examination revealed that the tumor cells were strongly positive for CD34. The fusion transcripts of the collagen type 1 alpha 1 platelet-derived growth factor beta chain were not detected. After excluding other fibroblastic tumors through histopathological and immunohistochemical examinations, a diagnosis of superficial CD34-positive fibroblastic tumor (SCPFT) was made. SCPFT is a recently proposed fibroblastic tumor that is characterized by striking pleomorphism, granular cytoplasm, low mitotic rate and diffuse CD34 expression. Only two reports with 20 cases have been reported so far. The present case is the first that corresponds to SCPFT in Japan.