Necrobiosis lipoidica with mucin deposition in a patient with autoimmune thyroiditis

Abstract

Dear Editor, Necrobiosis lipoidica (NL) is a relatively rare chronic granulomatous dermatitis of unknown etiology. We describe here a unique case of NL with mucin deposition in a patient with autoimmune thyroiditis.A 53-year-old Japanese man noticed the development of diplopia. Magnetic resonance imaging showed swelling of the extra-orbital muscles, consistent with thyroid-associated orbitopathy. Thyroid function tests showed a normal level of free triiodothyronine (2.74 pg/mL; normal, 2.20-4.40), a decreased level of free thyroxine (0.68 ng/dL; normal, 1.00-1.80), an elevated level of thyroid-stimulating hormone (TSH) (14.

The Intersection of Dermatological Dilemmas and Endocrinological Complexities: Understanding Necrobiosis Lipoidica—A Comprehensive Review

“…In particular cases, there may be lymphocytic aggregates, sometimes with germinal centers, found in the deep dermis or subcutaneous tissue [7]. Another unusual histopathological finding might be the presence of mucin, which has been linked to NL associated with autoimmune thyroiditis [8].…”

Non-Infectious Granulomatous Dermatoses

“…[ 4 ] The necrobiosis appears red on hematoxylin and eosin (red granuloma) because of hyalinization [ Figure 6b ]. [ 36 37 ] Mucin deposition is usually absent, however, some amount of mucin deposition has been reported in rare cases of NBL, making it difficult to differentiate from GA.[ 38 ] Nuclear dust may be present inside the area of necrobiosis and elastic fibers are usually diminished in the center. The necrobiosis often extends into the superficial subcutis and entraps degenerated fat.…”