Intramedullary lumbosacral teratoma in a domestic ferret (Mustela putorius furo)

Musculoskeletal and Neurologic Diseases

Ferrets may exhibit neurologic signs as a result of various conditions that may be of nervous or muscular origin. Neurologic examination follows the same principles as in small animal medicine. One of the main defect that may be screened during clinical examination is deafness. Congenital deafness in ferrets is associated with coat color patterns such as white markings and premature graying.In this species, paresis is a common presentation and may reflect a generalized weakness. Spinal disorder, intervertebral disk disease, and neoplasia are among the differential diagnosis. Diagnostic exams usually include advance diagnostic imaging such as CT-scan associated with myelography. Seizure is usually associated with hypoglycemia and insulinoma, but other causes such as hypocalcemia or intracranial disorders have been described. Ferrets are sensitive to various neurotropic infectious disease such as rabies, distemper, aleutian disease, or systemic coronavirus. Finally, muscular disorder such as disseminated idiopathic myofasciitis and myasthenia gravis have been recently described, and potential treatments have been intended.

Neoplasia in Ferrets

Neoplasia is a common cause of disease in domestic ferrets worldwide. The most common neoplasms are islet cell tumors (insulinoma), adrenocortical neoplasms, and lymphoma. The definitive etiology has yet to be defined, but husbandry, genetic predisposition and infectious agents are postulated causes. Definitive diagnosis requires sampling and microscopic analysis of the neoplasm, but initial testing including blood, urine and diagnostic imaging can aid the diagnostic process. Based on the type of tumor and its location, therapeutic options include surgery, chemotherapy and radiation therapy. Numerous chemotherapeutic protocols and drugs have been published for the use in ferrets and a ferret specific formula for calculating body surface area has been established. In addition to the more commonly affected endocrine and hemolymphatic systems, ferrets can also develop tumors in the skin and subcutis, gastrointestinal and reproductive tracts, musculoskeletal, nervous, urinary, respiratory and vascular systems.

Caudal Homeobox Gene-2 Staining Defines Intracranial Mature Teratoma with Differentiation to Colonic Adenocarcinoma

BACKGROUND

Malignant transformation of a mature intracranial teratoma into an adenocarcinoma is an extremely rare event and portends a poor prognosis. The clinical progression, radiographic changes, histopathological findings, and immunohistochemistry findings from these unique cases might provide clues regarding this transformation. Caudal homeobox gene-2 (CDX-2) is a specific and robust marker for colonic adenocarcinomas and can also be used to identify differentiation of mature intracranial teratoma into colonic-type adenocarcinoma. To the best of our knowledge, this is the first case report of the use of this specific marker for an intracranial malignancy.

CASE DESCRIPTION

We present the case of a 55-year-old right-handed Hispanic-American woman with progressive headaches who was found to have a left posterior parietotemporal tumor with intraventricular extension. Surgical debulking was performed, and the pathologic examination revealed a mature teratoma. Despite surgical resection and radiotherapy, the teratoma progressed to a malignant mature intracranial teratoma both radiographically and histologically. Histological analysis of the third specimen revealed a moderately differentiated adenocarcinoma. The tumor cells were positive for CDX-2 and cytokeratin 20 and negative for cytokeratin 7 and thyroid transcription factor-1, consistent with an enteric/colonic-type adenocarcinoma, demonstrating progressive atypia and malignancy.

CONCLUSIONS

Malignant transformation of a mature intracranial teratoma portends a poor prognosis. The exact histopathological diagnosis can facilitate treatment of these patients. CDX-2 is a specific robust marker for identifying differentiation of a mature intracranial teratoma into a colonic adenocarcinoma. This positive staining can also be observed in primary colonic and other adenocarcinomas. To the best of our knowledge, this is the first report of the use of CDX-2 in the diagnosis of an intracranial malignancy. The triangulation of clinical progression, radiographic findings, and histopathological and immunohistochemistry findings provided clues regarding this unique transformation.

Invasive histiocytic sarcoma of the lumbar spine in a ferret (Mustela putorius furo)

This report describes the history, clinical examination and histopathology of a histiocytic sarcoma in a domestic ferret. Clinical signs were acute paraplegia and dysuria. Physical examination revealed a firm, smooth, touch-sensitive mass in and around the lumbar vertebral column. Neurologic examination was consistent with a lesion between spinal cord segments T3 and L3. Magnetic resonance images revealed bone lesions of L2 and L3 combined with compression of the spinal cord due to a homogenous, isointense mass that was diagnosed as a malignant round cell tumour and the ferret was euthanased. Histopathology confirmed the diagnosis of an infiltrative histiocytic sarcoma.

Ferret Oncology: Diseases, Diagnostics, and Therapeutics

Neoplastic disease is common in ferrets. Approximately half of all tumors diagnosed in ferrets are located in the endocrine or hemolymphatic system. Many factors may influence the choice of treatment. Medical management of adrenal tumors has a greater disease-free period compared to adrenalectomy. In ferrets with an insulinoma, no difference is seen in the mean survival time of medically and surgically treated patients. Aside from medical and surgical treatment modalities, chemotherapy and radiation therapy have also been described in ferrets in other types of tumors. The outcome of these treatment modalities is not always favorable.

Congenital abnormalities of the vertebral column in ferrets

Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little information is available on the normal vertebral formula and congenital variants in this species. The purpose of this retrospective study was to describe vertebral formulas and prevalence of congenital vertebral anomalies in a sample of pet ferrets. Radiographs of 172 pet ferrets (96 males and 76 females) were included in this retrospective study. In 143 ferrets (83.14%), five different formulas of the vertebral column were recorded with normal morphology of vertebrae (rib attachment included) but with a variable number of thoracic (Th), lumbar (L), and sacral (S) vertebrae. The number of cervical (C) vertebrae was constant in all examined animals. Observed vertebral formulas were C7/Th14/L6/S3 (51.74%), C7/Th14/L6/S4 (22.10%), C7/Th14/L7/S3 (6.98%), C7/Th15/L6/S3 (1.74%), and C7/Th15/L6/S4 (0.58%). Formula C7/Th14/L6/S4 was significantly more common in males than in females (P < 0.05). Congenital spinal abnormalities were found in 29 ferrets (16.86%), mostly localized in the thoracolumbar and lumbosacral regions. The cervical region was affected in only one case. Transitional vertebrae represented the most common congenital abnormalities (26 ferrets) in the thoracolumbar (13 ferrets) and lumbosacral regions (10 ferrets) or simultaneously in both regions (three ferrets). Other vertebral anomalies included block (two ferrets) and wedge vertebra (one ferret). Spina bifida was not detected. Findings from the current study indicated that vertebral formulas may vary in ferrets and congenital abnormalities are common. This should be taken into consideration for surgical planning.