Well‐differentiated hepatic carcinoid in a dog: Long‐term survival following partial hepatectomy

Abstract

An 11-year-old, female, spayed Shetland sheepdog was referred for a 48-hour onset of lethargy, inappetence, pigmenturia and intra-abdominal mass of unknown origin. Laboratory sampling identified regenerative anaemia, hyperbilirubinemia, hypercholesterolemia and elevated alanine transaminase and alkaline phosphatase. Bilirubinuria and haematuria were noted on urinalysis. Thoracic radiographs were unremarkable. Ultrasonographic examination identified free abdominal fluid and a heterogeneous mass associated with a medial liver lobe. Haemoabdomen was confirmed, and partial hepatectomy was performed. Histopathology identified neoplastic cells arranged in nests and rosettes. On immunohistochemistry, neoplastic cells were positive for neuron-specific enolase and synaptophysin and negative for S100, chromogranin A and cytokeratin. Transmission electron microscopy revealed small round electrodense granules consistent with neuroendocrine granules. A final diagnosis of hepatic carcinoid was made. The dog received no adjuvant treatment. Re-staging with conventional imaging was performed every 3 months. No local recurrence or metastatic disease was identified within a 21-month follow-up period.