Papillary Carcinoma of Thyroid Developing in a Dyshormonogenetic Goitre: a Report of Two Cases in One Family

Dyshormonogenetic goitre is a rare condition frequently managed conservatively. Its association with malignancy has rarely been documented. We report three siblings with dyshormonogenetic goitre born to parents of consanguineous marriage. The eldest sibling had symptoms of hypothyroidism at 3 months of age; the second had a goitre at birth, while the youngest was screen detected to have hypothyroidism at birth. All three siblings were euthyroid on supplementation with levothyroxine. All of them developed an asymptomatic goitre which gradually increased in size over a decade. Though ultrasound and FNAC of the thyroid did not reveal a malignant lesion, all three underwent total thyroidectomy in view of the large size of the goitre. Histopathology revealed a well-differentiated thyroid carcinoma in two of the siblings - one with a macro follicular variant of papillary carcinoma while the other a micropapillary carcinoma. The sibling with the macro carcinoma underwent a(131)I whole-body scan following thyroidectomy which was negative for metastatic disease. All three siblings are doing well on follow-up. Although a benign condition, the possibility of development of an associated well-differentiated thyroid carcinoma should be kept in mind while evaluating these patients.