Black thyroid adenoma. Clinical, histochemical, and ultrastructural features.
A 22-year-old woman with a "hot" thyroid nodule who was being treated with minocycline for severe acne vulgaris is presented. A partial thyroidectomy specimen revealed a black adenoma. Microscopically, the black pigment was found in the follicular cells and the colloid of the adenoma. The pigment was bleached with potassium permanganate and was Fontana-Masson stain positive. It was negative for iron, periodic acid-Schiff, and acid-fast Ziehl-Neelsen stains. All these feature suggest a melanin-like pigment. However, electron microscopic examination revealed a dense osmophilic material present within the lysosomes of the follicular cells. No melanosomes were present. Twenty-six previously reported cases are reviewed, and the possible mechanisms for the deposition of the pigment in the adenoma and its relation to minocycline degradation products are discussed.
Koren
R
R
Department of Pathology, Hasharon Hospital, Petah Tikva, Israel.
Bernheim
J
J
Schachter
P
P
Schwartz
A
A
Siegal
A
A
Gal
R
R
D000152:Acne Vulgaris / Q000188:drug therapy; D000236:Adenoma / Q000378:metabolism* / Q000473:pathology* / Q000648:ultrastructure; D000328:Adult; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000493:pharmacokinetics; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D008854:Microscopy, Electron; D008911:Minocycline / Q000009:adverse effects / Q000493:pharmacokinetics; D010858:Pigmentation; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000648:ultrastructure
D000900:Anti-Bacterial Agents; D008911:Minocycline