[412] Cytopathology of Exra-Cranial Meningiomas: Study Involving 11 Ectopic and Metastatic Meningiomas

Rebecca Ocque, Walid E Khalbuss, Sara E Monaco, Pamela Michelow, Liron Pantanowitz. UPMC, Pittsburgh, PA; University of the Witwatersrand, National Health Laboratory Service, Johannesburg, South Africa

Background: Although rare outside of the cranium, meningiomas can be seen throughout the body either as ectopic or metastatic tumors. The cytomorphology of these neoplasms is not well documented. The rarity of such lesions and the fact they may exhibit morphological characteristics that overlap with other tumors poses a significant diagnostic challenge. The aim of this study is to characterize the cytomorphology of ectopic and metastatic meningiomas with histologic correlation in 11 cases.
Design: A retrospective analysis of 8 primary ectopic and 3 metastatic meningiomas with cytologic preparations [5 fine needle aspirations (FNA) and 4 intraoperative smears/touch preparations] were collected from our laboratory information system or collaborators (2 FNA cases) and correlated with available surgical resection specimens. Data regarding clinical findings, cytomorphology, histologic features and immunostaining (IHC) were recorded and analyzed.
Results: Patients were on average 50 years of age (range 30-71) with a male:female ratio of 1:3. Two of the 3 patients with metastases had a previous diagnosis (2/4; 50%). Metastases were diagnosed in the lung (2/3; 67%) and liver (1/3; 33%). Primary ectopic meningiomas were located in the sinuses and ear (4/8; 50%), orbit (2/8; 25%), and neck (2/8; 25%). The 4 cases associated with on-site evaluation were deferred (2 favored meningioma, 1 epithelioid neoplasm, and 1 atypical). Cytomorphologic features characteristic of meningiomas included clusters of spindled cells arranged in whorls (4 cases), intranuclear inclusions (5 cases), nuclear grooves (5 cases) and psammomatous calcification (3 cases). Unusual cytomorphologic features included epithelioid cell predominance (2 cases), abundant inflammation (2 cases), small cell change (1 case), papillary (1 case) and pseudoacinar growth (1 case). Metastatic tumors all had nuclear atypia (3/3; 100%) and mitoses (1 case) or necrosis (1 case). In 6 cases where IHC was performed, positive stains included EMA (100%), vimentin (100%) and pankeratin (33%); and all tumors were S-100 negative. High-grade features were seen in surgical resections of all metastases (one grade 2, two grade 3) and one ectopic meningioma (grade 2).
Conclusions: Metastatic and primary ectopic meningiomas can be encountered in cytologic specimens. Such tumors should be included in the differential when characteristic cytomorphologic features of meningiomas are seen. Cytopathologists should be aware that these lesions could be mistaken for other tumors.
Category: Cytopathology

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 89, Wednesday Afternoon


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