Myxopapillary ependymoma: cytomorphologic characteristics and differential diagnosis.

Myxopapillary ependymoma (ME) is a rare tumor with a predilection for sacrococcygeal area of adults. We present the cytomorphology of one such case in a 21-yr-old man, diagnosed by fine-needle aspiration (FNA). The tumor disclosed biphasic morphology with nests and aggregates of epithelioid malignant cells as well as branching cords of myxohyaline material. Most noticeable was the presence of distinct hyaline globules surrounded by neoplastic cells. The differential diagnosis of ME includes chordoma, adenoid cystic carcinoma, mucinous adenocarcinoma, and germ cell tumor. An accurate preoperative diagnosis of ME on FNA can be achieved based on its distinctive cytomorphologic features.