Neurological paraneoplastic syndrome caused by small cell lung cancer: a case report.

Paraneoplastic syndrome (PNS) is a term used to describe pathological changes in organ function among patients with malignancy that does not metastasize. Clinical manifestations affect nerve, digestive, hematopoietic, endocrine, bone, joint, and urinary function. Here we present the case of a 59-year-old male with PNS as the initial symptom of SCLC. PNS symptoms manifested as repeated attacks after surgery and chemotherapy. The severity of the patient's symptoms has rarely been reported. The tumor type involved most frequently is small-cell lung cancer (SCLC). Symptoms caused by PNS typically manifest earlier than those caused by the tumor. Immunohistochemical staining was positive for Syn, CgA, CD56, TTF-1, CK (AE1/AE3), Hu antibodies, and Ki67 (90%). Treatment remains challenging. A case of severe Neurological PNS caused by early small cell carcinoma was reported. Although the patient accepted surgery and postoperative radiotherapy and chemotherapy, symptoms persist. In this case report, treatment with pregabalin and antidepressant agents improved the patient's numbness. Currently, the patient has been followed-up for >3 years without any signs of recurrence and PNS. This case may inform future treatment of patients with PNS.