Local amyloidosis of the pineal gland

Abstract

Introduction. The pineal gland is supplied with blood by branches of the posterior choroidal artery, and the blood drains into the great cerebral vein or its tributaries. This gland may undergo local amyloid damage without involving the large hemispheres. Thus, this damage is an independent process not related to Alzheimer’s disease. The aim of the study was to determine the incidence of local amyloidosis in pineal glands of adults and to study a possible connection of amyloidosis with calcification of the gland. Methods. This pathohistological study was performed in 92 suicides and 69 victims of murders and accidents (the comparison group), a total of 37 women and 124 men. The mean age of male and female suicides was 41.0±13.0 and 57.0±15.0 yrs, respectively, and the mean age of men and women in the comparison group was 41.0±13.0 and 54.0±13.0 yrs, respectively. Amyloid lesion and calcinates were detected with Congo red and thioflavin T staining. Severity of the amyloid lesion and the number of calcinates in the pineal gland were scored conventionally. Differences in findings were analyzed using the Kolmogorov-Smirnov test with Lilliefors significance correction. Results. Congo red staining revealed pineal amyloid lesions of varying severity and the presence of calcinates in 48.5% of cases, regardless of the age, gender or the cause of death. The incidence and severity of amyloid lesions and the number of calcinates in the pineal gland did not depend on the age, gender or the cause of death. However, in suicides, the pineal gland weight was significantly increased (154.0±89.0 mg (D 64.0÷298.0, p=0.0143) compared to the weight of pineal glands from victims of accidents and murders (104.0±34.0 mg (D 51.0÷198.0)). This increase depended on the severity of the amyloid process. In the absence of amyloid lesions, there were no differences in pineal gland weights between suicides and non-suicides. Local amyloidosis of the pineal gland is possibly caused by hematogenic flux of bacteria, which also leads to the formation of calcinates. Conclusions. Approximately 50% of the population had asymptomatic, local amyloidosis of the pineal gland. The presence of amyloidosis was not the cause of suicide. In suicides, the wet weight of the pineal gland depended on the severity of amyloid lesion.