Cytomorphologic spectrum in paraganglioma.

Objective: To study the detailed cytologic features of paragangliomas (PGs) and delineate features helpful in predicting behavior.
Study Design: We performed retrospective analysis of 12 cases cytologically suggested as PG over a period of 10 years. Smears were reviewed for cellularity, pattern, shape, cytoplasm, nuclear features and background. Cytologic diagnosis was correlated with clinicoradiologic features, histologic features and immunocytochemistry.
Results: Patient age ranged from 12 to 65 years, with male preponderance; they presented with a mass lesion. Sites involved were head and neck (5), retroperitoneum (5) and mediastinum (2). Smears were cellular; cells were round to oval, plasmacytoid and spindled and seen as scattered, in clusters, acinar and perivascular pattern. The most consistent feature was presence of pink granules. Pleomorphism was present in all but 1 case and less prominent in tumors with metastasis. Mitoses were more frequently seen in malignant cases.
Conclusion: Cytologic features of PG are diverse. Although there are certain main features, they are not diagnostic unless combined with data on site, histology and ancillary studies. Presence of granules, mild pleomorphism, frequent mitoses and necrosis needs careful evaluation for malignancy potential and warrants close follow-up.