Spontaneous Malignant Craniopharyngioma in an Albino Rat

Abstract

Craniopharyngioma is a rare neoplasm in the rat, and few cases have been described. These lesions are thought to originate from squamous cell remnants of Rathke's pouch, an evagination of primitive stomatodeum. This neoplasm is usually locally invasive, and neither cranial nor extracranial metastases have been described. A spontaneously occurring malignant, metastasizing craniopharyngioma arising from the neurohypophysis was detected in a 2-year-old male albino rat. The infiltrative growth was observed in the wall of the vessels of the circle of Willis, in the perivascular space of Virchow and Robin, in the submeningeal space near the hypothalamus, through the fissura chorioidea, in the medulla oblongata, and along the optic nerve into the periocular region. Metastases were detected in the thalamus and hippocampus. The diagnosis was made on the basis of microscopic, immunocytochemical and ultrastructural findings.

Morphologic Characterization of Spontaneous Nervous System Tumors in Mice and Rats

“…Medulloblastoma has been described both in rats and (17,19,35,69,70,78) (Table 7). Certain tumorlike lesions, such as lipomas (lipomatous hamartoma) and epidermoid cysts, appear to be more frequent in mice than in rats (3,48 (14,102).…”

The Spectrum of Malignancy in Craniopharyngioma

“…There is, however, one reported example in an albino rat; histologically, it was a squamous cell carcinoma. 44 A meta-analysis of our 3 cases with update of those in the literature indicates a slight predilection for females (male to female ratio, 4:5), recurrences/reoperations numbering 1 to 7 (mean, 3.4), and a mean age with presentation of the malignant transformation of 29 years (range 10 to 63). Eight patients had undergone radiation therapy before the development of carcinoma.…”

Two Cases of Feline Malignant Craniopharyngioma

“…The immunohistochemical and electron microscopic findings, which supported the epithelial origin of the tumor, were also identical to those in other animals. 5,9 The present feline cases were, therefore, diagnosed as craniopharyngioma. Pituitary adenoma/adenocarcinoma, chordoma, meningioma and granular cell tumor were considered as differential diagnoses of the present cases, but all were ruled out by morphologic differences.…”