Does Percutaneous Thyroid Laser Ablation Induce Mixed Papillary and Medullary Thyroid Carcinoma ?

Abstract

Mixed medullary-papillary carcinomas are very rare and still not listed in the WHO classification (1988). The rarity of the co-existence of medullary and papillary carcinoma suggests that these cases represent mere coincidence. Some studies have shown that radiation exposure has induced neoplasia in the two cell types in rats. But we still have limited information about the carcinogenetic effect of laser ablation on the thyroid gland. This report describes the first case of thyroid carcinoma that demonstrated both medullary carcinoma and papillary components in the thyroid, which might occur due to percutaneous thyroid laser ablation.

Cytologic features of a case of mixed medullary and follicular cell‐derived thyroid carcinoma with review of the literature

“…At presentation, calcitonin, carcinoembryonic antigen (CEA), and TG levels can be elevated 2,7 . Ultrasonographic features are suggestive of but not specific for malignancy 2,8 . Surgical specimens reveal a usually solitary, firm, white, unencapsulated nodule with an average size of approximately 3 cm (range: 0.4‐5.5 cm) 2 …”

“…Immunohistochemistry demonstrates reactivity for “C‐cell markers” (calcitonin and CEA) and neuroendocrine markers in the MTC component and TG in the follicular cell‐derived component 2,7,8,11 . TTF‐1 is expressed by both 2 .…”

“…Two theories on the histogenesis of MMFTC attempt to address the simultaneous presence of two distinct carcinomas. The stem cell theory holds that the two cell populations are derived from neoplastically transformed uncommitted stem cells capable of differentiating into independent cell populations 8 . Alternatively, the hostage histogenic theory suggests that a developing neoplasia may encircle normal thyroid tissue, triggering oncogenesis 10 .…”