Yes, you read that right! There are a few rare cases of endometriosis that have been found in men. I read an article the other day that addressed this issue, and I was shocked! Before I wrote this blog, however, I wanted to verify that this is actually true. Well, it is. It’s rare, but it has happened.
A study published in 1985 by Martin and Hauck¹ looked at an 83-year-old man who had an endometrioma on his lower abdominal wall. The researchers reference several other cases that have been reported in the literature. The theory for the development of endometriosis-like tissue in the male at that time was that it developed from remnants of the prostatic utricle, or remnants of the uterus. They discuss how female remnants may be present as some men may be genetically mosaic – that is, they may have some female cells (46,XX) along with the normal male cells (46,XY). However, they point out that in this case, the 83-year-old man had only 46,XY cells (a normal male karyotype). The researchers go on to say that this man was thought to have prostate cancer but was later found to have adenocarcinoma. He had been placed on 25 mg. TACE which he took for ten years. It is extremely interesting to note that TACE, also known as chlorotrianisene, is a type of estrogen. It has since been discontinued from use.
A more recent study done in 2014 by Jabr and Venk² addresses a case of abdominal pain in a 52-year-old man with a history of cirrhosis and hepatitis C. He had two previous surgeries for an inguinal hernia within a two-year period. He presented to the emergency room with excruciating pain in his right lower abdomen and pelvis. A mass was found attached to the urinary bladder, and it extended into the inguinal canal. The mass was removed and tested, and it was found to be positive for both estrogen and progesterone receptors. The findings were consistent with endometriosis. The researchers note that cirrhosis is known to be associated with high estradiol levels.
Jabr and Venk go on to discuss several other previous studies. Endometrial-like tissue was discovered in two men with prostate cancer, both of which had been treated with estrogen for several years. The researchers also point out that another man was diagnosed with endometriosis after inguinal hernia surgery. They hypothesize that inguinal surgery coupled with high estrogen levels may increase the risk of development of endometriosis in the male. They also state induction appears to be a likely pathway for the development of endometriosis. Induction is the formation of endometriotic-like tissue as the result of unknown factors, endogenous or exogenous, inducing change in undifferentiated mesenchymal or embryonic cells.
Most people think of endometriosis as a disorder that affects women only; however, it has been seen in men. It is important to note this as it may give us much-needed information as to what factors play a role in the development of this disorder. According to these few studies, it appears that estrogen (estradiol) may play a pivotal role in the development of endometriosis and adenomyosis. I hope that more studies in men are forthcoming.
¹Martin, JD Jr., and Hauck, H.E. (1985). Endometriosis in the male. Am Surg, 51(7):426-30. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/4014886
²Jabr, F.I., and Mani, V. (2014). An unusual case of abdominal pain in a male patient: Endometriosis. Avicenna Journal of Medicine, 4(4):99-101. doi:10.4103/2231-0770.140660