Gestational trophoblastic disease (GTD), including complete hydatidiform mole, affects approximately 1 per 1000 pregnancies and represents an obstetrical emergency complicated by excessive β-hCG secretion. The structural homology between β-hCG and thyroid-stimulating hormone (TSH) enables cross-reactivity at TSH receptors, stimulating thyroid hormone production. In molar pregnancy, β-hCG levels frequently exceed 100,000 mIU/mL with reduced sialylation, markedly increasing thyrotropic potency. This hormonal overstimulation can precipitate thyroid storm, a life-threatening endocrine emergency with mortality rates of 15-30% if inadequately managed. Early recognition and meticulous preoperative stabilization are essential to prevent this severe complication.

A 21-year-old female with no prior thyroid disease presented with palpitations, tremors, heat intolerance, hypogastric pain, and vaginal bleeding. Physical examination revealed tachycardia (126 bpm), pallor, and scleral icterus. Transrectal ultrasound demonstrated an enlarged uterus with an intrauterine mass exhibiting the characteristic "snowstorm" appearance and bilateral multilocular theca lutein cysts, highly suggestive of molar pregnancy. Laboratory investigations confirmed severe thyrotoxicosis with suppressed TSH (<0.01 mIU/L), markedly elevated free T4 (>20 pg/mL) and free T3 (>5.0 ng/dL), and deranged liver function tests indicating hepatic involvement. Critically, her Burch-Wartofsky Point Scale score of 30 indicated impending thyroid storm, necessitating urgent intervention.

Preoperative stabilization was initiated with propylthiouracil to inhibit thyroid hormone synthesis, propranolol for beta-blockade and sympathetic control, and intravenous dexamethasone to reduce peripheral T4 to T3 conversion. Following successful medical stabilization, the patient underwent uncomplicated suction dilation and curettage. Histopathologic examination confirmed a complete hydatidiform mole. Postoperatively, free T4 levels declined significantly. The patient was transitioned to methimazole maintenance therapy and received prophylactic methotrexate due to persistently elevated β-hCG levels, essential for monitoring potential post-molar gestational trophoblastic neoplasia. She achieved clinical and biochemical euthyroidism during follow-up, with thyrotoxicosis resolving following molar evacuation and β-hCG normalization.

This case underscores the critical importance of routine thyroid function assessment in molar pregnancy patients, particularly those presenting with adrenergic symptoms or high tumor burden. Impending thyroid storm must be anticipated and aggressively managed preoperatively. Preemptive medical stabilization is mandatory before surgical intervention to prevent life-threatening complications. A coordinated multidisciplinary approach involving endocrinology, gynecology, and critical care teams is essential for optimizing patient safety and outcomes in this rare but serious complication of GTD.