Thyroid diffuse lipomatosis: a rare and benign disease

Eva Lau; Paula Freitas; Frederica Goncalves; Joana Pardal; Catarina Eloy; Luis Matos-Lima; Davide Carvalho

doi:10.1530/endoabs.32.P1027

P1027

Prev Next

Section Contents Cite

Endocrine Abstracts (2013) 32 P1027 | DOI: 10.1530/endoabs.32.P1027

ECE2013 Poster Presentations Thyroid (non-cancer) (100 abstracts)

Thyroid diffuse lipomatosis: a rare and benign disease

Eva Lau ^1, , Paula Freitas ^1, , Frederica Gonçalves ^2, , Joana Pardal ⁴ , Catarina Eloy ^4, , Luís Matos-Lima ³ & Davide Carvalho ^1,

Err

Author affiliations

¹Departments of Endocrinology, Diabetes and Metabolism, Centro Hospitalar São João, Oporto, Portugal; ²Faculty of Medicine, Centro Hospitalar São João, Oporto, Portugal; ³Surgery, Centro Hospitalar São João, Oporto, Portugal; ⁴Pathology, Centro Hospitalar São João, Oporto, Portugal; ⁵Institute of Pathology and Immunology Molecular, University of Porto, Oporto, Portugal.

Introduction: Diffuse lipomatosis of the thyroid is a very rare disease, characterized by extensive infiltration of thyroid parenchyma by mature adipose tissue. It is not accompanied by accumulation of amyloid fibrils.

Clinical report: Male, 47 years old, followed in Endocrinology by hypothyroidism, since 13 years old, medicated with levothyroxine, with unremarkable growth and pshicomotor development. In 2002, thyroid echography showed a solid and heterogeneous lesion (6.6×3.3 cm size), suggestive of a lipomatosis formation. Fine needle biopsies were always inconclusive. In 2010, CT and MRI showed the same cervical lipomatosis lesion (15×6, 5×4, 9 cm), occupying the entire thyroid anatomic region and extending till the retropharyngeal space.

Micro biopsy revealed: ‘fibro-fatty tissue surrounding regular thyroid follicles’. Surgical excision of the neck mass showed an extensive infiltration of the thyroid parenchyma by mature adipose tissue without atypia. These morphological findings and the history of subtotal thyroidectomy by thyroid nodule at 3 years of age with identical histological characteristics have allowed the diagnosis of diffuse lipomatosis of the thyroid gland.

Conclusion: The pathophysiology of adipose tissue infiltration in the thyroid gland is not clear. The definitive treatment is surgery and most of the lesions are benign. The prognosis is favourable.