Histoplasmosis mimicking malignant adenopathy during diagnostic thyroid lobectomy.

Abstract

Benign granulomatous disease may mimic malignant disease in the evaluation of mediastinal or pulmonary lesions. However, histoplasmosis as a cause of cervical lymphadenopathy is relatively rare. We report the first case of Histoplasma infection mimicking malignant adenopathy discovered during diagnostic thyroid lobectomy. A 2.5-cm, calcified, right paratracheal lymph node intimately involving the recurrent laryngeal nerve was discovered during lobectomy for a follicular lesion of undetermined significance with a positive NRAS mutation. Although metastatic thyroid cancer was the most probable diagnosis, results of gross inspection of the bisected thyroid nodule suggested a benign process. Partial removal of the node, sparing the nerve, established the diagnosis of Histoplasma capsulatum infection. Histoplasmosis is a rare cause of cervical adenopathy that should be considered in cases in which a discordance arises between the malignant gross appearance of the adenopathy and the benign gross appearance of an associated thyroid nodule.