Tumor fibroblástico inguinal superficial positivo para CD34: reporte de un caso y revisión de la literatura / Inguinal superficial cd34-positive fibroblastic tumor: case report and literature review

El tumor fibroblástico superficial de tejidos blandos positivo para antígeno CD34 (CD34) es un tumor raro, de baja frecuencia, que se caracteriza histológicamente por un marcado pleomorfismo, baja actividad mitótica, e inmunoreactividad difusa para CD34. Puede tener un comportamiento similar al de un tumor mesenquimal de malignidad intermedia. Existen sólo 52 casos publicados en la literatura. Se presenta el caso de una paciente de 31 años con una masa en tejidos blandos en región inguinal izquierda, de crecimiento progresivo, de varios meses de evolución dolorosa. La masa fue biopsiada y, con la sospecha de un tumor fibroblástico superficial positivo para CD34, fue posteriormente tratada con una resección ampliada de la lesión y con cobertura del defecto en la piel con un colgajo local de avance de V-Y, con una evolución satisfactoria en su seguimiento postquirúrgico. El reporte de patología confirmó la sospecha diagnóstica de un tumor con reactividad fuerte para CD34, con proteína P53 en 60% a 70%, antígeno Ki67 menor al 15%, sin pérdida de proteína nuclear INI-1, y negatividad para CD31, CD163, AE1AE3, CAM5.2, EMA, CD30, receptores de progestágenos, proteína S100, y desmina, con bordes negativos.

Superficial CD34 (CD34) antigen positive fibroblastic soft-tissue tumor is a rare, lowfrequency tumor, characterized histologically by marked pleomorphism, low mitotic activity, and diffuse immunoreactivity for CD34. It may behave like a mesenchymal tumor of intermediate malignancy. There are only 52 cases published in the literature. We present the case of a 31-year-old patient with a long progressive and painful growth of a soft-tissue lesion in the left inguinal region. The mass was biopsied and, with the suspicion of a superficial CD34-positive fibroblast tumor, it was subsequently treated with an enlarged resection of the lesion and covering the skin defect with a local V-Y advancement flap, with a satisfactory evolution in the postoperative follow-up. The pathology report confirmed the diagnostic suspicion of a tumor with strong reactivity for CD34, with P53 protein in 60% to 70%, Ki67 antigen in less than 15%, without loss of INI-1, and with negativity for CD31, CD163, AE1AE3, CAM5.2, EMA, CD30, progestin receptors, S100 protein and desmin, with negative borders.

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.