Clinical diagnosis of late temporal lobe necrosis following radiation therapy for nasopharyngeal carcinoma

Abstract

The entire colonic mucosa of 51 cases of colorectal carcinoma was examined histologically. Mucosal lesions including goblet cell hyperplasia, crypt dilatation, ulceration with regeneration, basal cell hyperplasia, metaplastic lesions, and adenomas were encountered. Goblet cell hyperplasia (80.4%) was most prominent adjacent to the carcinoma (transitional mucosa). Whether this represents a precancerous change is controversial. Crypt dilatation (57%) is considered a nonspecific change due to mucosal injury and indicates obstruction to the outlet of the crypts. Ulceration (6%) is often proximal to the carcinoma and is considered secondary to stasis and ischaemia due to obstruction. Basal cell hyperplasia is particularly prominent at the site of lymphoid follicles. It is suggested that the hyperplasia is a reactive response to the presence of stimuli in the intestinal content. It is observed that metaplastic lesions have their origin from these foci of basal cell hyperplasia. The presence of basal cell hyperplasia in metaplastic polyps (14%) indicates that they are active lesions in the process of formation and growth. The occurrence of metaplastic lesions may provide an indication of an adverse environment and a vulnerable mucosa. Adenomas have their origin from basal cells of colonic crypts. They are present in 47% of colorectal carcinoma. The findings support the view that adenomas are the most common and important precursor lesion associated with colorectal carcinoma in man. No de novo foci of malignant transformation was encountered but this does not exclude the possibility of de novo carcinogenesis of the colorectum.

Pathogenesis of Cognitive Decline Following Therapeutic Irradiation for Head and Neck Tumors

“…CT was found to be less sensitive, but those patients with positive CT manifested characteristic signs of nger-like hypodense areas and cyst-like shadows in the region of the temporal lobe. On the basis of histopathologic studies in these patients, Lee et al (20) suggested that the nger-like hypodense areas represented reactive white matter edema, while the cyst-like changes represented liquefactive necrosis with surrounding gliosis. In their study of a cohort of 60 patients treated for carcinoma of the nasopharynx, Leung et al (8) found a correlation between the volume of temporal lobe included in the high-dose region, the fractionation schemes employed, and the risk of temporal lobe injury.…”

“…H owever, there are only a few reports on brain injury following irradiation for extracranial neoplasms of the head and neck (10,19,20). These patients typically present with memory impairment, headache, seizure or dysphasia and on further evaluation are found to have radiological changes compatible with brain injury.…”

“…Lee et al reported on the largest series of patients developing temporal lobe injury following irradiation for cancer of the nasopharynx (20). M ost of their patients presented with dizziness, impairment of memory, headache and confusion.…”

“…H istopathological con rmation of temporal lobe damage following irradiation for nasopharyngeal carcinoma was reported in 12 patients, 3 cases revealed by biopsy and 9 found at autopsy (20). All showed the characteristic ndings of radiation damage: varying degrees of coagulative necrosis of the brain parenchyma and brohyaline changes in the blood vessels (23).…”

“…The typical features of these changes have been extensively studied. These consist of endothelial damage, hyaline thickening and brinoid necrosis of the vessel wall, presence of thrombosed vessels, and in ltration of abnormal multinucleated macrophage cells, loaded with fat (11,19,20,23). Similar changes have been found in vessels damaged by hypertension.…”