Concurrent mammary gland hyperplasia and adrenocortical carcinoma in a domestic ferret
Natan Mor, DVM, PhD; Charles W. Qualls, Jr., DVM, PhD; John P. Hoover, MS, DVM
A 5-year-old white castrated domestic ferret (Mustela putorius furo) was examined at the teaching hospital at Oklahoma State University because of alopecia over the back of 3 months’ du- ration. The abdomen was larger than normal and there were 2 bilateral, large lobulated caudal mammary masses. A similar mass had been previ- ously removed and diagnosed as mammary gland hyperplasia on histologic examination.ª Physical examination revealed no other abnormalities. Its intake of pelleted ferret food and water was normal. It had never been vaccinated.
A CBC and serum chemical values were normal. The urine (voided specimen) had a low specific gravity (1.013), and the ferret had marked pyuria. Abdominal radiography revealed loss of serosal detail with moderate peritoneal effusion. The fer- ret was anesthetized with isoflurane, and explor- atory surgery was performed. A smooth, firm, ap- proximately 4 × 3 × 3-cm mass was found at the cranial aspect of the right kidney. The mass involved the right adrenal gland, aorta, and caudal vena cava. An incisional biopsy was done. The nodular mammary masses (right 1 × 1 × 1 cm and left 3 X 1.5 X 1 cm) were excised.
Histologically, the mammary masses consisted of multilobular hyperplastic nodules of mammary glands. The nodules were composed of ducts with hyperplastic epithelial lining cells and scant stro- mal connective tissue (Fig 1). Many ducts con- tained proteinaceous material. The abdominal mass was composed of nests of well-differentiated po- lygonal cells with round to oval nuclei and prom- inent nucleoli and were separated by thin bands of fibrovascular connective tissue (Fig 2). Electron microscopy revealed the cells to be similar to the cells of the zona fasciculata or reticularis of the ad- renal gland. On the basis of the large size and gross infiltrative character of the tumor, it was classified as an adrenocortical carcinoma.
From the Departments of Veterinary Pathology (Mor, Qualls) and Veterinary Medicine and Surgery (Hoover), College of Vet- erinary Medicine, Oklahoma State University, Stillwater, OK 74078.
ªEly RW, Oklahoma Animal Disease Diagnostic Laboratory, Stillwater, Okla: Personal communication, 1991.
The proliferation of mammary ductular tissue is a normal physiologic feature of early pregnancy and represents a response of the mammary tissue to progesterone. It has been suggested that there might be an association between mammary hyper- trophy and hyperprogesteronism in cats.1 More- over, a neutered cat receiving progesterone for treatment of dermatitis and eosinophilic granulo- mas developed hyperplasia of the mammary gland.2 Hinton et al3 have reported 9 cases of mammary hypertrophy associated with pregnancy or with oral progesterone treatment in cats. Although these limited studies support the hypothesis that proges- terone is involved in the development of mammary hyperplasia, the exact pathogenesis remains un- clear. In the neutered ferret of this report, mam- mary gland hyperplasia was concurrent with an adrenocortical carcinoma. Adrenocortical neo- plasms in ferrets have been reported to be associ- ated with hyperadrenocorticism.4,5 In rare cases, these neoplasms may be associated with feminiza- tion.6 It is conceivable that, in this ferret, hyper- plasia of the mammary gland was associated with stimulation by endogenous hormones from the ad-
renal gland mass and the recent alopecia and der- matitis in this ferret may have been related to hy- peradrenocorticism. Alopecia has been associated with hyperadrenocorticism secondary to adreno- cortical tumors in ferrets.7 The ferret died 1 week after surgery and was not available for necropsy.
1. Allen HL. Feline mammary hypertrophy. Vet Pathol 1973;10:501-508.
2. Dorn SA, Legendre MA, McGavin DM. Mammary hy- perplasia in a male cat receiving progesterone. J Am Vet Med Assoc 1983;182:621-622.
3. Hinton M, Gaskell CJ. Non-neoplastic mammary hy- pertrophy in the cat associated either with pregnancy or with oral progesterone therapy. Vet Rec 1977;100:277-280.
4. Fox JG, Goad MEP, Garibaldi BA, et al. Hyperadreno- corticism in a ferret. J Am Vet Med Assoc 1987;191:343-344.
5. Paradis M, Bonneau HN, Morin M, et al. Hyperadreno- corticism in association with an adrenocortical adenoma in a pet ferret. Can Vet J 1989;30:60-62.
6. DeLellis AR. Endocrine system. In: Cotran SR, Kumar V, Robbins LS, eds. Robbins’ pathologic basis of disease. 4th ed. Philadelphia: WB Saunders Co, 1989;1260.
7. Kuper DS, Bauck L. Hyperadrenocorticism in a ferret: diagnosis (using ultrasound) and treatment. J Small Exotic Anim Med 1991;1:66-68.
Book Review: Cytology and Hematology of the Horse
Cowell and Tyler, editors and contributing authors of this text, are to be com- mended for producing a con- cise but comprehensive source of information that is ex- tremely useful to equine prac- titioners and veterinary stu- dents with an interest in equine medicine. The text is organized according to body systems and includes an intro- ductory chapter with detailed discussion of sample collec- tion, handling, preparation of smears, and staining methods. The introduction also provides a good review of the terms used in describing cytologic observations. Although much of the information in some chapters is applicable across species, indeed some of the photomicrographs are those
used in Cytology and Hematol- ogy of the Dog and Cat, most of the chapters deal almost exclu- sively with equine issues. Sub- headings and a good index allow rapid location of infor- mation on specific topics. Al- gorithms are provided through- out the text and are helpful in showing the logical sequence of cytologic diagnosis. All chapters are liberally illus- trated with schematic drawings and photographs of gross and microscopic appearance of samples and of collection and analytic procedures.
The book has some flaws that detract slightly from the overall excellent quality. Some of the photomicrographs are of poor color quality, and others should have been of higher original magnification to show
clearly the items of interest. A number of the figure captions contain minor errors, and some captions have been switched. Good reference lists follow each chapter, but some citations contain errors.
The book is modestly priced, considering the num- ber of color plates, and is well worth the purchase price to anyone who applies cytologic techniques to the diagnosis of disease in horses .- Cytology and Hematology of the Horse. Edited by Rick Cowell and Ron- ald Tyler. 242 pages; illustrated. American Veterinary Publica- tions Inc, 5782 Thornwood Dr, Goleta, CA 93117. 1992. Price 6.00 shipping .- JULIA BLUE