Case Report and Literature Review: Overexpression of HMGA in Concomitant Plurihormonal Tumor and Papillary Thyroid Carcinoma

This study described a case of plurihormonal tumor associated with papillary thyroid carcinoma (PTC) and summarized the treatment approaches for similar cases, while also exploring the underlying pathogenesis. The patient exhibited symptoms indicative of acromegaly, central hyperthyroidism, and hyperprolactinemia. A glucose loading test demonstrated persistently elevated growth hormone (GH) levels, while thyroid function tests revealed inappropriate thyroid stimulating hormone (TSH) secretion. Imaging of the pituitary gland revealed a 26 × 19 mm lesion compressing the optic chiasm. Thyroid ultrasound reveals bilateral Thyroid Imaging Reporting and Data System 4B nodules, with the largest on the right measuring 27 × 20 mm. Fine-needle aspiration cytology (FNAC) revealed the presence of PTC. Three weeks later, the patient underwent pituitary adenomectomy. Immunohistochemistry revealed a plurihormonal tumor positive for TSH, GH, luteinizing hormone (LH), prolactin (PRL), pituitary-specific transcription factor 1 (Pit1), and steroidogenic factor 1 (SF1). A total thyroidectomy followed 10 weeks post-adenomectomy. Immunohistochemical evaluation showed higher nuclear positivity for the high-mobility group AT-hook 1 (HMGA1) and the high-mobility group AT-hook 2 (HMGA2) proteins in neoplastic cells compared to normal tissues. In our search results, only three similar cases were identified, and we summarized the relevant literature search results which raise the possibility that the HMGA2-the Retinoblastoma Protein (pRB)/E2F Transcription Factor 1 (E2F1)-HMGA1 signaling pathway may represent a common pathogenic pathway for PTC and plurihormonal tumor. If a patient simultaneously suffers from PTC and plurihormonal tumor, the determination of the surgical sequence is crucial. In cases of postoperative recurrence, where patients are reluctant to undergo additional surgeries, targeting HMGA is likely to offer a promising approach to prevent the progression of both the pituitary tumors and PTC.