Thyroid Follicular Hyperplasia Associated With Massive Extracellular Mucin Deposition

Abstract

Extensive extracellular mucin deposition is a rare pathological thyroid condition with 6 cases described in literature so far. We report another case of a 67-year-old woman, discussing histopathological features, and review the literature. Our findings showed a diffuse mucin deposition in the stromal compartment of thyroid parenchyma. Histochemical stainings showed positivity for Alcian blue staining, but not for periodic acid–Shiff staining. Our case is peculiar because this mucin deposition was associated with benign nodular hyperplasia, in contrast with the other 6 reports, which described the same stromal alterations associated with benign or malignant thyroid tumors.