Coccygeal body revisited: An immunohistochemical study using donated elderly cadavers

Abstract

To describe the normal anatomy and histology of the adult coccygeal body (CB) and to discuss about the origin and function, using immunohistochemistry, we examined 29 CBs found in 32 elderly donated cadavers without macroscopic pathology in the pelvis. The CB was usually located in or near the anococcygeal ligaments. It was almost always composed of multiple masses or nodules of round glomus cells (smooth muscle actin or SMA++). However, the CB sometimes contained abundant dilated veins with scattered glomus cells. Thus, the CBs varied from the glomus cell nodule-dominant type, through an intermediate morphology with a mixture of nodules and veins, to the vein-dominant type. Each glomus cell mass was surrounded by abundant sympathetic nerves. In all specimens, we found multiple abnormal arteries, each of which carried a glomus-like cell layer around the almost -obliterated vascular lumen; as well as an SMA-negative thick arterial wall containing abundant sympathetic nerves. The ligaments around the CB are known to be under strong mechanical stress from the pelvic floor. We considered abnormal arteries containing the unique internal layer as an intermediate between a normal muscular artery and a glomus cell mass of CB. Under long-termed mechanical stress, a muscular artery seems to lose smooth muscles with increased sympathetic nerve fibers, to compensate for the lack of muscle function. Taken together with fetal morphology (our recent report), some or most of the CBs might not be an arteriovenous shunt but a result of stress-induced acquired transformation of pericytes. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1826-1837, 2017. © 2017 Wiley Periodicals, Inc.

Ganglion cardiacum or juxtaductal body of human fetuses

“…The ganglion cardiacum or juxtaductal body usually contains or is accompanied by a cluster of undifferentiated cells negative for both S100 and SMA. This non-neuronal cluster was similar to the coccygeal body, but the absence of SMA expression differentiated this cluster from the vessel-poor type of the coccygeal body [21]. Thus, these undifferentiated cells were unlikely to be of vascular origin.…”

“…The terms “body” and “mass,” being similar to the coccygeal body, suggest that these ganglia are larger in size than most ganglia and are histologically unique, as they contain many non-ganglionic cells. Non-ganglionic cells are major constituents of the coccygeal body and, because of their vascular origin, are strongly positive for expression of smooth muscle actin (SMA) [21]. This study was designed to describe the morphologies of the ganglion cardiacum or juxtaductal body in human fetuses and to compare these characteristics with those of intracardiac ganglia.…”

A missing distal complex of the external and internal anal sphincters: a macroscopic and histologic study using Japanese and German elderly cadavers

“…Over the last two decades, our group has examined large numbers of histological sections of anal canals in elderly subjects. These have included anterior walls in men [12,34] and women [25,31]; the lateral wall [2,9,16] and the posterior wall [13,15,17,18]. In them, we found no J-shapes EAS in the anterior and posterior anal walls, but aforementioned studies focused on sphincter-related nerves and fascial structures.…”

Fetal cervical zygapophysial joint with special reference to the associated synovial tissue: a histological study using near-term human fetuses

“…Blood in the synovial tributaries of veins likely pushed the joint cavity in the posterior direction. A cross-section of a specific vein in the synovial tissue exhibited an appearance similar to that of arteriovenous anastomosis, which should contain smooth muscles, elastic fibers, arterial branches, and nerves [19][20][21]. However, we did not find elastic fibers or arterial branches around the synovial vein.…”