Mixed medullary and follicular cell thyroid carcinoma in a dog

Abstract

A 12-y-old, castrated male Weimaraner dog was presented for a wellness examination. A 7-cm, firm mass was palpated on the left, ventral, mid-lateral neck. The neck mass was removed surgically and submitted for histopathology. A thyroid carcinoma was diagnosed based on microscopic examination. Immunohistochemistry for chromogranin-A, calcitonin, and thyroglobulin identified dual immunoreactivity of the latter two, and a final diagnosis was of a well-differentiated, compact, mixed medullary and follicular cell thyroid carcinoma. These neoplasms are rare in humans and have not been reported in dogs, to our knowledge.

Sodium iodide symporter immunolabelling as a predictor of clinical iodide uptake in canine thyroid carcinoma: A preliminary study

“…This may represent divergent differentiation within the tumour or an origin from a pluripotent stem cell. 27 The clinical utility of NIS IHC and the ability to predict candidacy for I-131 therapy is specific for follicular thyroid neoplasms, so additional medullary tumours were not included; however, all tumours would need to be assessed in prospective evaluation. The differences in NIS IHC uptake between follicular and medullary thyroid neoplasms in the dog could then be characterised further.…”

“…Interestingly, this tumour did not have membranous NIS labelling, but it did have weak, diffuse cytoplasmic labelling. This may represent divergent differentiation within the tumour or an origin from a pluripotent stem cell 27 . The clinical utility of NIS IHC and the ability to predict candidacy for I‐131 therapy is specific for follicular thyroid neoplasms, so additional medullary tumours were not included; however, all tumours would need to be assessed in prospective evaluation.…”