Paraganglioma: Cytomorphologic features, radiologic and clinical findings in 12 cases.

BACKGROUND: The cytologic diagnosis of paraganglioma can be challenging because of its rarity, wide anatomic distribution, and variable cytomorphological features.

DESIGN: The Johns Hopkins Hospital pathology archives were searched for fine-needle aspiration (FNA) specimens confirmed as paraganglioma on histology (2003-2015).

RESULTS: Twelve specimens from 10 patients (6 males and 4 females) with an age range of 16-81 years (mean = 47) were included. Anatomic location included neck (n = 4), paraspinal (n = 2), retroperitoneum (n = 2), and peripancreatic (n = 2). Cellularity of cytological specimens ranged from scant to hypercellular. The cells were arranged in clusters (n = 7), single cells (n = 6), acini (n = 3), and syncytium (n = 1). Plasmacytoid (n = 5) and spindled cells (n = 6) were often present. Nuclear details included anisonucleosis (n = 8), marked pleomorphism (n = 8), scattered binucleation and/or multinucleation, nuclear knobbing (n = 2), speckled (n = 3), coarse (n = 2), hyperchromatic chromatin (n = 3), nuclear grooves (n = 6), intranuclear pseudoinclusions (n = 2), prominent nucleoli (n = 1), naked nuclei (n = 7), and rare nuclear streaking artifact (n = 2). Cytoplasm was delicate, abundant, and granular (n = 9). Necrosis (n = 1) was rare. Synaptophysin, chromogranin, CD56, and S100 (only in sustentacular cells) were positive in tested cases. Three cases showed loss of Succinate Dehydrogenase Subunit B (SDHB). Two patients developed metachronous lesions at different sites. Three patients developed recurrence at the surgical site. Metastatic paraganglioma to the lymph nodes (n = 2), bone (n = 1), and lung (n = 1) also occurred.

CONCLUSION: An accurate diagnosis of paraganglioma on FNA specimens is crucial for proper treatment. SDH status should be considered for all patients with paraganglioma as it may be important for patients' lifelong follow-up as well as for familial considerations. Paraganglioma is a rare entity with wide age and anatomic distribution and variable cytomorphological features that often overlap with those of malignant neoplasms. Possible aggressive behavior such as recurrence and metastasis to lymph nodes, bone, and lung as well as Succinate Dehydrogenase complex mutations warrant an accurate diagnosis on aspirated material for appropriate clinical management.