ABSTRACT Electrolyte disturbances are frequent in advanced cancers, with hypercalcemia being well recognized. In contrast, hypocalcemia is uncommon and rarely described in anaplastic thyroid carcinoma (ATC) without prior surgery. A 75‐year‐old woman with diabetes presented with breathlessness, stridor, and cough. Examination revealed a hard thyroid mass with tracheostomy, and imaging confirmed metastatic ATC. Owing to her frailty and advanced disease, curative or systemic therapies were not possible, and palliative radiotherapy was deferred. During admission, she developed persistent symptomatic hypocalcemia (corrected calcium 3.9–5.8 mg/dL), compounded by hypomagnesemia and vitamin D deficiency. Despite intravenous calcium, magnesium, and vitamin D supplementation, only partial response was achieved, and she experienced recurrent carpopedal spasms. Supportive measures—including oxygen therapy, corticosteroids, opioids, and tracheostomy care—were prioritized alongside repeated family discussions. Her care remained focused on comfort until she died on the eighteenth hospital day. This case illustrates how metabolic disturbances such as refractory hypocalcemia can worsen suffering in ATC. This case highlights the importance of routine electrolyte monitoring and early recognition of complex metabolic disturbances, including hypocalcemia, in patients with advanced anaplastic thyroid carcinoma to optimize supportive care and prevent life‐threatening complications.
Jasmin et al. (Mon,) studied this question.