Papillary carcinoma in amyloid goitre

Amyloid goitre is a rare lesion characterized by a diffuse and bilateral en largement of the thyroid gland due to amyloid deposition. It is uncommon th at a massive and widespread amount of adipose tissue deposition is found wi thin these lesions and only in exceptional cases a differentiated carcinoma can develop. We describe the third example of thyroid carcinoma, arising i n a 74-year old female who had also massive adipose thyroidal metaplasia, w ithin amyloid goitre. The Congo red stain confirmed the diagnosis of amyloi d goitre. Immunohistochemistry showed reactivity with MoAb against amyloid fibril protein A. The patient suffered from renal failure of undetermined a etiology for three years, but neither systemic amyloidosis nor risk factors for its development were found. It is important to correctly diagnose amyloid goitre both to rule out the p resence of a differentiated thyroidal carcinoma and to search for amyloid i nfiltration in other organs in view of an early appropriate therapy.