Nature of the perineural space invaded by prostatic carcinoma

Abstract

The concept of perineural lymphatics is widely accepted, particularly in reference to prostatic carcinoma. A study of serial sections of many tissue blocks from 12 prostatic carcinomas revealed involvement of perineurium in only five cases; however, the assumption that these tumor cells are in lymphatics is unlikely because of the absence of an endothelial lining and the involvement of the entire circumference of the nerve by tumor in some instances. Experimental studies were performed to further investigate the perineurium. When India ink was injected into the lymphatics of the prostatic capsule of dogs, none was found in perineural areas either grossly or microscopically. Inoculation of Walker 256 carcinoma directly into the perineurium of femoral nerves of rats resulted in variable spread within the nerve and along tissue spaces in the perineurium, with no evidence of invasion of lymphatics or regional lymph nodes. Electron microscopy of canine and human nerves did not reveal any evidence of lymphatics in the perineurium. Therefore, the authors conclude that spread of malignant tumors along nerves in the prostate and elsewhere is not within performed lymphatics but within tissue planes of least resistance.

Growth and Survival Mechanisms Associated with Perineural Invasion in Prostate Cancer

“…Rodin et al (2) demonstrated that the perineural space was devoid of lymphatic vessels and, in the absence of a biological explanation, concluded that PNI was a purely physical phenomenon. Cancer cells found a pre-established dissemination route of "least resistance" in the perineural space (2).…”

Generation and Impact of Neural Invasion in Pancreatic Cancer

“…along neural lymph vessels(di Mola&di Sebastiano, 2008), which, however, could not be confirmed in later studies. In later studies, investigators suggested that PCa cells grow along the path of least resistance after entering nerves, which was thought to be the perineural space (Rodin et al, 1967;Bockman et al, 1994;di Mola&di Sebastiano, 2008). Indeed, a higher proliferative index and decreased apoptosis in the perineural space could previously be shown for prostate cancer cells invading nerves (Ayala et al, 2004).…”

Histopathological Changes in Surrounding Tissue of the Sciatic Nerve after Spinal Cord Injury in Rats

“…However, there is no anatomical description of the space between the perineurium and the nerve bundle, even though perineural invasion has been identified in carcinoma. This space attracts attention as the perineural space 24,25) . From the results of experimental and clinical studies, it has become generally accepted that the perineural space does not communicate with the lymphatic system 24,25) .…”

“…This space attracts attention as the perineural space 24,25) . From the results of experimental and clinical studies, it has become generally accepted that the perineural space does not communicate with the lymphatic system 24,25) . Although, it is evident that the perineural space exists between the perineurium and nerve bundle of autonomic nerves, research regarding the existence of the perineural space in somatic nerves has not been performed.…”