Spontaneous Tumor Lysis Syndrome Secondary to Small-CellNeuroendocrine Carcinoma of Unknown Origin: A Rare CaseReport and Literature Review

Spontaneous tumor lysis syndrome (STLS), in the absence of prior chemo or radiation therapy, is rare with solid tumors. Here, wepresent a case of STLS secondary to a small-cell neuroendocrine tumor of unknown origin in a 66-year-old female patient whopresented with abdominal discomfort. Computed tomography (CT) abdomen showed a large tumor mass with peritonealmetastasis, and she developed renal failure from STLS, resulting in the need for hemodialysis. Due to the progressivedeterioration and the comorbidities, she opted for comfort care. Timely recognition and intervention of STLS is critical. Furtherstudies evaluating STLS in solid tumor patients are recommended.