Loose cell clusters with vascular coats: Zellballen pattern of paraganglioma on cytology
We describe a case of a 42-year-old woman presenting with fever on and off since 1 year and neck swelling of 5 months duration. Ultrasonography (USG) showed a well-defined heterogeneous highly vascular lesion in right cervical region. Thyroid, parotid, submandibular gland and neck vessels were normal. Clinical impression was lymph node metastasis or a carotid body tumor. Clinical examination revealed a solitary 3 cm × 2 cm non-mobile non-tender mass present at the right angle of mandible. FNAC was bloody and Pap stained smears revealed cells in clusters, microacinar and rosette like formations as well as singly. The cells were monomorphic, round to plasmacytoid with round to oval nuclei and a moderate amount of pale granular cytoplasm. There was evidence of mild anisonucleosis. Many of the cells showed stippled nuclear chromatin. There were in addition, few large loose clusters of cells enveloped by vascular channels on all sides. The cells within these clusters were arranged in curved rows. These cells showed same cytomorphologic features as surrounding cells [Figure and ]. There was no evidence of necrosis or mucin in the smears.\nIn view of monomorphic cells with the absence of necrosis and mucin, metastatic adenocarcinoma was ruled out. Metastasis of medullary carcinoma of the thyroid was considered on cytomorphology, but was ruled out on the basis of a normal thyroid on USG and absence of specific cytologic features. Hence a cytological diagnosis of carotid body paraganglioma was offered. After 2 weeks, the patient underwent surgical excision with due precautions. Histopathological examination confirmed the diagnosis of a benign carotid body paraganglioma [].