Shrestha Milan, Yadav Ajay K, Shrestha Ramila, Khadka Dibas, Paudel Mukesh S
Department of Gastroenterology, Bir Hospital, National Academy of Medical Sciences, Kathmandu, NPL.
Cureus. 2025 Jun 22;17(6):e86542. doi: 10.7759/cureus.86542. eCollection 2025 Jun.
Chronic diarrhea is characterized by an increased frequency of loose stools persisting for more than four weeks. Diagnosing chronic diarrhea requires a comprehensive evaluation that includes a detailed medical history, physical examination, and investigations guided by diagnostic clues. Diarrhea is often the presenting symptom of various underlying conditions. Medullary thyroid carcinoma is a rare neuroendocrine tumor derived from the parafollicular C cells of the thyroid gland. It can occur sporadically or be inherited as a part of a syndrome, such as multiple endocrine neoplasia type 2. Chronic diarrhea can be a presenting symptom of medullary thyroid carcinoma and should always be considered in the differential diagnosis, particularly if the patient has a palpable thyroid nodule. This case report describes a 65-year-old woman with a rare metastatic medullary thyroid carcinoma who presented with chronic diarrhea and a palpable thyroid mass. Fine needle aspiration cytology and histopathological examination of the thyroid gland confirmed a diagnosis of medullary thyroid carcinoma. The diagnosis was also supported by increased calcitonin and carcinoembryonic antigen levels, which can be used for prognostication and monitoring response to therapy. She was treated with a tyrosine kinase inhibitor, which substantially alleviated her diarrhea, but she succumbed eventually to metastatic complications.
慢性腹泻的特征是稀便频率增加，持续超过四周。诊断慢性腹泻需要进行全面评估，包括详细的病史、体格检查以及根据诊断线索进行的检查。腹泻常常是各种潜在疾病的表现症状。甲状腺髓样癌是一种罕见的神经内分泌肿瘤，起源于甲状腺的滤泡旁C细胞。它可以散发性发生，也可作为综合征的一部分遗传，如2型多发性内分泌腺瘤病。慢性腹泻可能是甲状腺髓样癌的表现症状，在鉴别诊断中应始终予以考虑，特别是当患者有可触及的甲状腺结节时。本病例报告描述了一名65岁患有罕见转移性甲状腺髓样癌的女性，她表现为慢性腹泻和可触及的甲状腺肿块。甲状腺细针穿刺细胞学检查和组织病理学检查确诊为甲状腺髓样癌。降钙素和癌胚抗原水平升高也支持该诊断，这些指标可用于预后评估和监测治疗反应。她接受了酪氨酸激酶抑制剂治疗，腹泻症状得到显著缓解，但最终因转移性并发症死亡。
