Diagnosing a cribriform papillary thyroid cancer in a patient with familial adenomatous polyposis
Do Cao Christine, El Ouahabi Hanan, Berdelou Amandine, Leuteurtre Emmanuelle, Carnaille Bruno, Beron Amandine & Wemeau Jean Louis
Papillary thyroid carcinoma (PTC) is the most common malignancy originating from the thyroid gland. Although occurring predominantly as a sporadic disease, it may be associated with rare inherited circumstances such as familial adenomatous polyposis (FAP) FAP is an autosomal dominantly inherited cancer predisposition syndrome characterized by the progressive development of colorectal carcinoma. Most of available data report accompanying thyroid carcinoma in no more than 12% of FAP patients. Ninety-five percent of these cases are papillary thyroid carcinoma, most of them corresponding to an unusual subtype, called cribriform histotype.
We describe the case of a 30-year-female presenting with a thyroid mass. She reported a familial history of adenomatous polyposis, had undergone a total colectomy at the age of 14. Physical examination revealed an asymetric goiter containing several palpable nodules in the right lobe. Ultrasound demonstrated six nodules in the right lobe and three smaller nodules in the left lobe, Enlarged lymph nodes were also seen within both submandibular triangles. Aspiration cytology under sonographic guidance performed in the right dominant nodule strongly suggested diagnosis of PTC. Computed tomography scan confirmed the presence of multiple thyroid nodules. TSH level, serum calcitonin and carcinoembryonic antigen measurements were within normal limits. Total thyroidectomy with a central compartment neck node dissection was performed and the patient was later referred for radio metabolic treatment as malignancy was confirmed.
The pathology report actually gave the diagnosis of multifocal cribriform morular variant of PTC with immunohistochemical staining for the presence of estrogen and progesteron receptors. On genetic analysis, germline mutation was identified at codon 637 of the APC gene.
Special attention has to be devoted to cervical examination in patients with FAP as cribriform papillary thyroid cancer can develop early in young adults. It can be notably suspected in presence of multiple thyroid nodules sharing the same ultrasound features.