Comparison of cytological features of myxopapillary ependymomas on crush preparations

Abstract

Myxopapillary ependymoma (ME) is a rare neoplasm found predominantly in the sacro-coccygeal region in adults and is characterized by its distinct epithelial and stromal components. From 1990 to April 2008, a total of 10 ME cases were recorded at our institution. Six out of 10 cases underwent frozen section examination with concomitant crush preparations, which forms the basis of this study. The clinical and cytologic findings in all six cases were reviewed. There were four males and two females. The age ranges from 15 to 36 years with a mean age of 27 years. The epithelial component of ME is strikingly similar for all six cases showing tumor cells appearing singly or in loose clusters, most with papillary branching. There was also presence of indistinct cell boundaries, tapered cytoplasmic prolongations, wispy/fragile cytoplasm, and uniform oval-to-fusiform shaped nuclei with an evenly distributed chromatin pattern. The stromal component was composed mainly of thick, metachromatic material and adenoid cystic-like areas. One case showed rosette-like structures. These aforementioned characteristics can be utilized to distinguish ME from other primary and metastatic tumors such as meningioma, adenoid cystic carcinoma, chordoma, mucinous adenocarcinoma, chondrosarcoma, and germ cell tumors.

Myxopapillary ependymoma: Lesser known cytomorphologic features

“…Bradly et al . [ 15 ] studied cytological features of MPE's on crush preparations. The cytologic findings in six cases were reviewed.…”

Cytopathologic characteristics and differential diagnostic considerations of osteolytic myxopapillary ependymoma

“…(4) Metastatic papillary adenocarcinoma may mimic the cytomorphology of osteolytic MPE, thus presenting yet another potential pitfall. However, obvious cytological features of nuclear pleomorphism with prominent nucleoli and the absence of glial fibrillary process together with a detailed systemic examination would reliably exclude the possibility of a metastatic papillary tumor . Moreover, MPE may show an unusual morphologic type on smears and closely mimicking adenoid cystic carcinoma .…”

Inguinal lymph nodal metastasis of myxopapillary ependymoma confirmed by fine‐needle aspiration cytology, biopsy, and immunohistochemistry: Case report

“…A diagnostically important group of lesions involving the sacrum, spinal canal, and parasacral soft tissues is characterized by a myxoid or mucinous background in cytologic smears 8–10. This group of myxoid/mucoid neoplasms includes chordoma, ME, metastatic mucinous adenocarcinoma, and extraskeletal myxoid chondrosarcoma 10.…”

“…Despite the similarity of the background substance, each neoplasm within this differential diagnosis has a characteristic composite set of morphologic and immunophenotypic features. Because many of these masses are not easily surgically biopsied, FNA is often used for their diagnosis 7, 8…”