Ectasias of the subcapsular sinus in lymph nodes of athymic and euthymic rats: a relation to immunodeficiency

G. Sainte-Marie, F.S. Peng and G. Guay

Department of Anatomy, Universite de Montreal, Montreal, Quebec, Canada

Offprint requests to: Dr. Guy Sainte-Marie, Department of Anatomy, University of Montreal, C.P. 6128 Suoc A, Montreal (Quebec), Canada

Summary. This paper describes a morphologically unusual feature occurring in lymph nodes of some aged euthymic animals but mostly athymic animals. It initially consists of small alveole-like excrescences of the cortical wall of the subcapsular sinus. With dilatation, an excrescence becomes an ectasia which expands into the cortex. Observations suggest that ectasias enlarge under the influence of an increased pressure of the afferent lymph of a node. Such condition conceivably results from a greater lymph formation due to inflamation of the drained tissue site, combined with an impairment to the flow of lymph from the subcapsular sinus into medullary sinuses. A probable relation of ectasia formation to immunodeficiency is discussed. This formation results in the atrophy of the affected lymphoid cell populations of a node which likely contributes to aggravate the deficiency of the immune system. Histol Histopathol 12, 637-643 (1997)

Key words: Lymph node, Sinusal ectasia, Immunodeficiency, Aging, Athymic rat

DOI: 10.14670/HH-12.637