Immunohistochemical Evaluation of a Malignant Intestinal Carcinoid in a Dog

Abstract

An intestinal carcinoid with multiple metastases was identified in a 5-year-old male Shih Tzu with a clinical history of anemia, fatigue, anorexia, vomiting, intermittent diarrhea, intestinal bleeding, and progressive emaciation. There was a yellowish-white mass 15 mm in diameter in the anterior jejunum and white nodules consistent with metastases in many organs. Histopathologically, the mass consisted of neoplastic cells arranged in lobules, trabeculae, or closely interdigitating islands of cells. Neoplastic cells were generally polygonal with round hyperchromatic nuclei, modest amounts of eosinophilic cytoplasm, and eosinophilic cytoplasmic granules. Mitoses were common. Rosette formations of tumor cells were apparent in metastatic tumors. Immunohistochemically, tumor cells stained positive for cytokeratin 13, synaptophysin, protein gene product 9.5, neuron-specific enolase, chromogranin A, calcitonin gene-related peptide, serotonin (5-HT), and Leu-7. Serum 5-HT concentrations for this dog were increased 10-fold compared with those of normal dogs. All findings were consistent with a diagnosis of a malignant intestinal carcinoid.

Management of non‐lymphomatous small intestinal tumours in dogs and cats

“…Intestinal carcinoid neoplasia can follow an aggressive course (Patnaik and others 1980, Sako and others 2003). …”

A Neuroendocrine Carcinoma of Undetermined Origin in a Dog

“…In humans, NE tumors (so-called carcinoids) have been found in a wide range of organs, the gastrointestinal and pulmonary tracts being the most common sites 1 – 3 . In domestic animals, NE tumors have occasionally been reported in the intestine, liver, bile duct, lungs, gall bladder, esophagus, skin and nasal cavity 4 – 13 . NE tumors usually have histopathological features forming sheets, nests or cords of small to medium-sized cells separated by delicate fibrovascular stroma to give an endocrine-type pocketing.…”

“…NE tumors usually have histopathological features forming sheets, nests or cords of small to medium-sized cells separated by delicate fibrovascular stroma to give an endocrine-type pocketing. More extensive destruction and invasion are rarely found 3 , 13 . Both immunohistochemical examination with antibody specific for neuropeptides and electron microscopical examination are useful for the differential diagnosis of these neoplasms in human patients and animals 14 …”

A Feline Case of Hepatic Neuroendocrine Carcinoma with Gastrin Immunoreactivity

“…In dogs and cats, the case reports concerning these tumors have been limited. Previously, neuroendocrine carcinomas were found in several organs including the intestines [6, 10, 13], skin [4, 7], nasal cavity [11], bile duct [5], gallbladder [5] and liver [2, 5, 8, 9]. Moreover, hepatic neuroendocrine carcinomas have been very rare in the cats.…”