RESUMO
The coccygeal body is one of the least studied and most mysterious structures of the human body. The insufficient investigation of its morphology has provoked a lot of controversy, especially in relation to its function. It has been assumed to act as a gland similar to the carotid body, or as a part of chromaffin system, or even as a large variant of arteriovenous anastomotic glomus body [glomus coccygcus]. So, this study aimed to throw more light on its early [fetal] morphology that would enable a better understanding of its function. The specimens included 16 postmortem male fetuses [abortions] ranged between 16 weeks and full term. The coccyx with the pericoccygeal soft tissue were dissected [in block], divided into two symmetrical halves and processed for paraffin and semithin sections. The present examination showed a constant [anatomical] presence of the epithelioid cell clusters characteristic of the coccygeal body in all the examined ages. Two patterns of clusters could be distinguished: A more encountered capsulated cluster [coccygeal body] and a less encountered perivaseular clusters or cuffs that could be better termed [glonius coccygeus]. The clusters were mainly found precoccygcal, less commonly at the tip, or rarely posicoccygeal; accordingly, the term [pericoccygcal body] could be proposed. Special stains revealed the contractile nature of the epihelioid cells; while, no chromallin granules or nerve fibers could be detected. It was concluded that it could be assumed that there are two types of coccygeal bodies that might possess different functions. Moreover, pathologists should be aware of this normally present [anatomical] structure and not to be mistaken with the glomus tumor of coccyx