Cyto-Architectural Complexity of Dyshormonogenic Goitre can Closely Mimic a Thyroid Follicular Malignancy: A Case Report and Review of the Literature to Avoid Diagnostic Pitfall

A 13-year-old male child presented in the OPD with a midline 5x4cm thyroid swelling of 2 years duration with the chief complaint of difficulty in breathing. He also had growth and mental retardation since 3 years of age. His thyroid profile records revealed a severe degree of hypothyroidism and he was on thyroxine supplement since then. He underwent a right hemithyroidectomy for the right-sided nodular goitre causing on-and-off dyspnea. The gross specimen measured 5x4x3cm, which on cut section showed partially encapsulated multi-nodular solid areas. Microscopy yielded marked architectural complexity and prominent cellular and nuclear pleomorphism that mimicked a thyroid malignancy; for eg., a poorly differentiated papillary or follicular carcinoma. However, a thorough assessment of a range of histo-morphological features in the context of clinical history clinched the diagnosis of dyshormonogenetic goitre. One year postoperatively the patient is doing well on Thyroxine supplement. This case report reviews the literature about this rare benign entity of dyshormonogenetic goitre which closely mimics thyroid malignancy, notably a follicular malignancy on microscopy owing to its cytoarchitectural complexity and nuclear atypia. Hence, knowledge of its clinical presentation, gross and diverse microscopic features is extremely important to avoid misdiagnosis and thereby clinical management.