Phoebe's autopsy pictures
Phoebe's histopathlogy report
Diagnosis Pancreatic Endocrine Tumour - “Insulinoma” and Probable Lymphoma
Prognosis Not Applicable
Sections from necropsy samples of multiple tissues from a 6-year-old, neutered female Ferret, were examined microscopically.
LIVER (with GALL BLADDER): 1 sample received; 1 section examined.
The sinusoids and vasculature generally are mildly congested - probably terminal hypostatic congestion. There is patchy, very mild, lipid hepatocytic vacuolation, considered within acceptable normal limits, and there is also a single small focus of hepatocytic nodular hyperplasia - also not unusual in a ferret of this age and of minimal pathological significance. Otherwise the section is unremarkable.
KIDNEY: 2 samples received; 2 sections examined.
Single substantial areas of interstitial fibrosis, accompanied by moderate inflammation and associated with variable tubular and glomerular atrophy, are present in both kidneys, with several smaller areas also present in each. One contains a large cyst in the cortico-medullary region, partly lined by cuboidal epithelium and probably of tubular origin.
SPLEEN: 1 sample received; 1 section examined.
The red pulp is congested and includes a fair amount of extramedullary haemopoiesis, but the latter is within normal limits for a ferret. The lymphoid component (white pulp) is prominent and is populated predominantly by medium-sized, intermediately differentiated lymphocytes; with little evidence of maturation to small lymphocytes.
LUNG: 2 samples received; 2 sections examined.
These are both markedly congested and somewhat collapsed in appearance, though both were still floating in the fixative. Primary bronchi in both sections contain a large amount of mucus, in which neutrophils and large foamy macrophages are moderately numerous. Neutrophils are also present in slightly higher than normal numbers generally throughout the pulmonary parenchyma, but there is no evidence of significant alveolar effusions. No pathogens are seen.
HEART: 1 sample received; 1 section examined.
Apart from patchy, mild myocardial fibrosis, a common incidental finding at this age, this is histologically largely unremarkable.
STOMACH: 1 sample received; 1 section examined.
The sample is from the pyloric region. The surface epithelium is well-differentiated and intact; i.e. there is no overt evidence of ulceration, but the lamina propria is expanded by a fairly heavy, more or less diffuse infiltrate of mixed inflammatory cells. No Helicobacter organisms were seen in the surface mucus or in gland necks, and no other obvious pathogens were seen.
SMALL INTESTINE: 1 sample received; 1 section examined.
There is widespread villous fusion, distorting the mucosal architecture somewhat, and numbers of proprial leucocytes appear considerably increased. The mucosal vasculature is congested. No obvious pathogens are seen.
LARGE INTESTINE: 1 sample received; 1 section examined.
There is patchy erosion of the surface epithelium and proprial leucocyte numbers are fairly high, considered slightly increased above normal. Large numbers of bacteria are present in the lumen, but these may well just be the normal faecal flora.
PANCREAS: 2 samples received (one attached to intestine); 2 sections examined.
One of the sections is histologically largely unremarkable, but the other contains a single, large (histologically speaking) nodule of islet tissue, composed of reasonable well-differentiated islet cells, arrange in nests or variably anastomosing cords, mostly 2 or 3 cells thick, separated and surrounded by congested fibrovascular stroma. There is minimal atypia, negligible mitotic activity and no evidence of infiltrative behaviour.
ADRENAL GLAND: 1 sample received; 1 section examined.
Erupting through the capsule of the gland is a fairly substantial area of cortical hyperplasia, composed of a mixture of cells resembling those of the normal zonae fasciculata and reticularis. There is no appreciable atypia and no obvious increase in mitotic activity and although the capsule has been breached, the growth pattern is not aggressively infiltrative.
LYMPH NODES: 3 samples received (attached to stomach and intestine samples); 3 sections examined.
These nodes are all considerably larger than expected, partly due to marked dilation of the sinuses, a common finding in the mesenteric nodes of ferrets with enteritis, but a definite cause of which has not been established as fas as I am aware. In addition, in all three nodes there is a loss of the usually clear distinction between cortex and medulla, cortical follicles are absent or small and distinct, and the lymphocyte population is rather monomorphous, consisting of medium-sized lymphocytes rather than normal-looking small, mature lymphocytes. Mitoses are not particularly frequent (0 - 2 per 40x objective field). Lymphocytes are infiltrating from two of these nodes into adjacent adipose tissue.
1. Pancreas - Islet cell tumour (aka insulinoma).
2. Lymph nodes and spleen - Probable lymphoma.
3. Adrenal gland - Cortical hyperplasia; moderate.
4. GI Tract - Gastroenteritis; moderately severe.
5. Kidneys - Chronic interstitial nephritis; moderate.
6. Lungs - Bronchopneumonia; mild.
DISCUSSION: This Ferret was suffering from a variety of pathological processes in various organs.
According to most sources, pancreatic islet cell tumours are the commonest neoplasms of ferrets. They arise mostly from the beta cells and secrete insulin, hence their popular name of “insulinoma”. Clinical signs are referable to hypoglycaemia.
The changes in the spleen and lymph nodes are typical of early lymphoma, although the possibility of advanced, atypical lymphoid hyperplasia is not ruled out completely. Malignant lymphoma (lymphosarcoma) vies with insulinoma as the commonest neoplasm of the domestic ferret and it is not particularly uncommon for the two to occur concurrently.
Proliferations of the adrenal cortex (hyperplasia, adenoma and carcinoma) are extremely common in the ferret, particularly neutered individuals.
There is also evidence of moderately severe gastroenteritis, moderate chronic interstitial nephritis and mild bronchopneumonia in this ferret, but specific causes of these were not identified in the sections examined and the appearances are not specific for any particular aetiology.