The present study was conducted on six healthy early neonatal and six prepubertal buffalo calves to study the location, gross morphology, histomorphology and histochemistry of lymphoglandular complexes in proximal colon. In very proximal part of colon of buffalo calves, an irregular oval mucosal lymphoid patch was found grossly as a proximal colon (PC) patch. Histologically, in proximal colon patch of early neonates (3-4 weeks), an extensive invasion of mucosal glands was observed towards lymphoid nodules that were present in submucosa. The structure as a whole thus formed a complex known as lymphoglandular complex (LGC). Large number of such complexes i.e., LGCs were observed in submucosa of proximal colon at this age. At some places, invasion of mucosal glands into lymphoid tissue was restricted to superficial layer of complexes, with the lymphoglandular complexes opening directly into the lumen but some were deep seated. However, by the age of 6 months in buffalo calves i.e., prepubertal period, LGCs were reduced and were present in single layer within the submucosa of the proximal colon. Moreover, some of LGCs were completely encapsulated by their own lamina muscularis mucosae. But some of the complexes still had their mucosal openings into lumen while others had lost their connection with tunica mucosa. Histochemically, the glands that were observed within LGCs contained mucosubstances, glycogen, mucopolysaccharides, and mucin. However, lipids were present around the lymphocytes observed towards the periphery of these LGCs.
KEY WORDS: Proximal colon; Lymphoglandular complex; Histomorphology; Histochemistry; Buffalo calves.