Histiocytosis X involving thyroid gland: a case report.

Diffuse histiocytosis X involving thyroid gland is rare. A 10-year-old boy with progressively enlarged neck mass, skin rash over scalp and face, splinter hemorrhage, otitis externa, episodes of pneumothorax and abnormal liver function was hospitalized. Thyroid scan showed a nonfunctioning mass in the right lobe of the thyroid and needle aspiration biopsy suspected histiocytosis X. Right thyroid lobectomy was performed and revealed histiocytosis X in light and electron microscopic examinations.