Minocycline and Black Thyroid

Abstract

THYROID pigmentation was discovered during surgical exploration for nodular thyroid in a patient who had been taking minocycline hydrochloride for six years. Total thyroidectomy was performed. Preoperative thyroid function studies had given results within normal limits. Report of a Case A 37-year-old woman was first seen in September 1980 for asymptomatic palpable thyroid nodule. Results of thyroid function studies—thyroxine level, triiodothyronine resin uptake, and thyroid-binding capacity—were within normal limits. Thyroid uptake scan demonstrated a right-lobe nodule of the same density as the surrounding thyroid. She was given levothyroxine sodium, 0.5 mg/day, with no subsequent change in the mass. The patient was admitted to the Baptist Medical Centers, Birmingham, Ala, in March 1981 for surgical resection. At surgery, the thyroid was noted to be uniformly black and to have a bosselated surface. A portion of the right thyroid was resected and submitted for frozen-section examination. The frozen section was interpreted as