A 72-year-old female presented with weight loss and poor oral intake. Multiple hepatic massesand enlarged lymph nodes (LNs) observed on imaging raised the suspicion of metastatic disease.
Esophagogastroduodenoscopy and colonoscopy were unremarkable. Liver biopsy confirmedthe diagnosis of metastatic small cell neuroendocrine carcinoma, with immunohistochemistry(IHC) findings indicative of the primary tumor being from the lungs (CK [AE1/3]+,TTF-1+, INSM1+, CD45-, Vimentin-). Widespread metastases to the liver, LNs, and boneswere evident on positron emission tomography-computed tomography. The patient underwentfour cycles of chemotherapy with etoposide and cisplatin (EP regimen); however, pneumoniaand anemia complicated the treatment and the patient had to be referred to hospice care. Thiscase highlights the importance of IHC in diagnosing metastatic disease and the challenges ofmanaging extensive metastases in elderly patients with comorbidities.