Cytojournal
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Parathyroid gland and their tumors comprise a small proportion of non-palpable neck masses that are investigated by ultrasound (US) guided fine needle aspiration biopsy. We reviewed our institution's cases of US guided FNAB of parathyroid gland and their lesions to determine the role of cytology for the preoperative diagnosis of parathyroid gland and their lesions. ⋯ US-guided FNAB is a useful test for confirming the diagnosis of not only clinically suspected parathyroid gland and lesions but also for detecting parathyroid glands in unexpected locations such as in thyroid bed or within the thyroid gland. Although there is significant overlap in the cytomorphologic features of cells derived from parathyroid and thyroid gland, the presence of stippled nuclear chromatin, prominent vascular proliferation with attached epithelial cells, and frequent occurrence of single cells/naked nuclei are useful clues that favor parathyroid origin. Distinction of the different parathyroid lesions including hyperplasia, adenoma, and carcinoma cannot be made solely on cytology. Immunostaining for PTH can be performed on destained Pap smears and cell block sections which can be valuable for confirming parathyroid origin of the cells.