We present 5 uncommon cases: One case of perineal canal in a female; two cases of perineal groove in females, one with normal anus and another with ectopic perineal anus. Two cases of perineal canal in males. The canal is deep in the perineum, runs forward above the root of scrotum, close to the floor of the urethra (which is normal), and opens on the undersurface of the penis. One of them is associated with covered anus incomplete with anocutaneous fistula as well opening on the scrotal raphe. In all 5 cases the perineal canal or gutter opens posteriorly in the ectodermal anal canal, immediately below the line of anal valves. A third look to the origin of these conditions will be discussed versus the 1st and 2nd looks of Stephens and Chatterjee. Embryological and histopathological studies will support our point of view.

The fossa navicularis (FN) is an anatomical variant on the ventral surface of the basilar part of the occipital bone that, to date, has only been investigated in bone specimens. We aim to clarify the structure of the fossa navicularis by gross anatomical, radiological, and histological methods. The FN was found in the occipital bone of the Caucasian male cadaver. There was no bony or histological continuity between the FN and posterior cranial fossa. The histological analysis found that the overlying tissue was composed of loose connective tissue with a mixture of collagen and elastic fibers and a vascular matrix including arteries, veins, and capillaries. There was no evidence of lymphoid, glandular, or notochordal tissues. As no previous studies have performed histological analysis of the FN, this report adds to our knowledge of tissues that are involved in its formation.

Direct insertion of the anterior papillary muscle (DPM) into the mitral valve is uncommon. During the routine dissection of an adult female, a DPM into the mitral valve with abnormal chordae tendinae was observed. This abnormal papillary muscle was measured as 28.0 mm in length from myocardial to insertion, 14.8 mm in width, and 7.0 mm in depth. The embryology, symptoms, associated cardiac diseases, and surgical precautions of this congenital malformation in the heart are reviewed.