Proximal-type epithelioid sarcoma of pharynx: A case report with immunohistochemical study

Epithelioid sarcoma (ES) usually occurs in extremities. ES shows characteristic granulomatous morphologies, and its prognosis is not so poor. Proximal-type ES (PT-ES) is a variant of ES, and is characterized by central locations, severe atypical features, and poor prognosis. Both ES and PT-ES histologically show epithelial and sarcomatous patterns, and immunohistochemically express both vimentin and cytokeratins. A 77-year-old man presented with sore throat. The laryngoscope revealed a large polypoid tumor (4 × 3 × 4 cm) in upper pharynx, and a large biopsy was taken. The biopsy showed malignant epithelioid and spindle tumor cells. There were no apparent transitions between normal epithelial cells and tumor cells. The tumor consisted of malignant epithelioid and spindle cells with marked anaplasia. The tumor showed marked infiltrative features and lymphovascular permiations. Mitotic figures, atypical mitosis, and necrotic areas were present. No apparent features of sarcomas were seen. No rhabdoid cells were seen. Immunohistochemically, the malignant cells were positive for vimentin (3 +, diffuse), CK AE1/3 (1 +, focal), CK CAM5.2 (1 +, diffuse), CK8 (1 +, focal), CK18 (1 +, focal), CD20 (1 +, focal), p53 (3 +, 84%), Ki-67 (labeling = 94%), CD68 (2 +, only focal), and anti-trypsin (2 +, only focal). They were negative for CK34BE12, CK5, CK6, CK7, CK14, CK19, CD99, CEA, CA19-9, CA125, EMA, S100 protein, NCAM, NSE, synaptophysin, chromogranin, α-smooth muscle actin, smooth muscle actin, desmin, CD34, CD31, CD45, D2-40, factor-VIII-related antigen, HMB-45, Melan-A, myoglobin, MDM2, CDK4, KIT, and PDGFRA. The author diagnosed this pharyngeal tumor as PT-ES, but the author cannot completely exclude the possibility of sarcomatoid carcinoma. The prognosis of patient was poor; the patient died of carcinomatosis 2 years after the manifestation.