Elevated procalcitonin levels in primary hepatic neuroendocrine carcinoma: Case report and literature review.

Rationale: Procalcitonin (PCT) has been identified as a tumor biomarker in medullary thyroid carcinoma. Other neuroendocrine carcinomas with elevated PCT levels are relatively rare, and are mainly reported in the lung, digestive tract, and pancreas. No studies in the literature have reported a case of primary hepatic carcinoma complicated with unexpectedly elevated PCT levels. Patient concerns: A 78-year-old man with persistent fatigue and mild fever was complicated with an extremely high PCT level. Radiological examination revealed a single hypodense lesion in the left lobe of the liver with a "rapid enhancement and rapid washout" pattern. Pathological analysis showed a poorly differentiated neuroendocrine carcinoma (grade 3) with multiple genetic mutations. Diagnosis: Primary hepatic neuroendocrine carcinoma. Interventions: The patient received antibiotic therapy and subsequent transcatheter hepatic arterial chemoembolization; a PCT assessment and computed tomography were performed during the follow-up. Outcomes: The PCT level did not decline after antibiotic therapy but greatly declined in response to effective transcatheter hepatic arterial chemoembolization. The patient survived and is still being followed up. Lessons: An extremely elevated PCT level may raise a suspicion of a neuroendocrine carcinoma and plays an indicative role as a biomarker during therapy.