For seven to eight months, a 36-year-old woman in India had heavy, drawn-out periods, cramping pain, and something more alarming: pieces of tissue coming out with the blood. When doctors examined her, they found a soft, reddish-brown mass about 5 by 5 centimeters at the opening of her cervix. Once it was removed, the tissue turned out to resemble a mold of the inside of her uterus.
The condition is called membranous dysmenorrhea. Instead of breaking into small pieces during a period, the uterine lining detaches and comes out in a single piece, known as an endometrial or decidual cast. Obstetricians at Dr. D. Y. Patil Medical College, Hospital and Research Centre in Pimpri, Pune, described the case in the September 2026 issue of the Journal of Clinical and Diagnostic Research.
What makes the report unusual is not just the cast itself. The patient had taken none of the hormonal medications doctors usually suspect when this happens.
A Cast Without Birth Control or Progesterone
Membranous dysmenorrhea is often linked to hormone use, especially progesterone-containing products. Cleveland Clinic notes that some research shows decidual casts may be related to hormonal contraceptives containing progesterone, as well as to ectopic pregnancy.
This patient did not fit that profile. According to the report, she had not used birth control pills or contraceptive injections, emergency contraception, fertility treatment, or herbal remedies. A hormone panel covering thyroid-stimulating hormone, prolactin, FSH, LH, and progesterone came back normal.
Her history did include one notable event. Before the bleeding and tissue began, she had gone about six months without a period. She had one child, delivered by cesarean section, and no other known medical conditions.
The authors, Dr. Swapnali Sansare and Dr. Aneesha Nallapati, wrote that the case shows “the condition can occur even in the absence of hormonal therapy,” noting that “spontaneous occurrences, as seen in the present case, are uncommon.”
Ruling Out Miscarriage and Other Look-Alikes
Passing a large piece of tissue can easily be mistaken for something more serious. The doctors had to rule out retained tissue from a pregnancy, an endometrial polyp, a submucosal fibroid growing into the uterine cavity, and the thickened lining that can form during an ectopic pregnancy.
A negative pregnancy test was a key first step. Ectopic pregnancy, in which a pregnancy develops outside the uterus, may be life-threatening, so clinicians need to exclude it before settling on a benign explanation.
A pelvic ultrasound showed a normal-sized uterus with no focal lesions and healthy ovaries. Her endometrium, the uterine lining, measured 18 millimeters thick, and there was mild free fluid behind the uterus.
The deciding evidence came from the lab. Under the microscope, the tissue showed pre-decidualized endometrial tissue with dilated, congested blood vessels and no signs of pregnancy tissue. That pattern matched membranous dysmenorrhea rather than a miscarriage or a growth.
The authors explain the pain of the condition as the result of a single intact cast being forced through a cervix that has not dilated. In this case, removing the cast with forceps brought immediate relief.
A Poorly Understood Condition With Few Proven Treatments
No one knows exactly why the lining sometimes comes out whole. The report lists hormonal imbalance leading to incomplete breakdown of the endometrium as one proposed explanation, but the authors describe the condition as having an unclear pathophysiology. It has been reported in women between the ages of 20 and 40.
Treatment is just as uncertain. “There is a lack of scientific evidence supporting the treatment modalities proposed for this condition,” the authors wrote. Their patient received monthly injections of leuprolide acetate for three months, along with pain medication.
Leuprolide is a gonadotropin-releasing hormone agonist that lowers certain hormone levels and is used for conditions such as endometriosis and anemia caused by fibroids. The doctors used it to temporarily suppress the uterine lining. She had no new episodes over three consecutive menstrual cycles of follow-up.
That outcome is encouraging but limited. This is a single case report with short follow-up, so it cannot show that leuprolide prevents recurrence or would help other patients. It also cannot explain why this woman developed the condition without any hormone exposure.
Rare, Frightening and Usually Not Dangerous
For anyone who passes a decidual cast, the experience can be startling. Cleveland Clinic describes the tissue as shaped like the uterine cavity, usually red or pink and fleshy. Symptoms can include severe cramps, pelvic pain, bleeding, nausea, and dizziness, and they typically ease once the tissue passes.
The condition is generally not considered a sign of a serious problem. Cleveland Clinic states that it has not been known to cause infertility and that there are typically no long-term complications, while emphasizing that pregnancy, including ectopic pregnancy, must be ruled out.
The Pune case adds to a small body of medical literature and makes a practical point for clinicians: hormone use is a common association, but its absence does not rule out the diagnosis.
Anyone who passes a large piece of tissue, has unusual vaginal bleeding or develops pelvic pain that feels different from usual cramps should speak with a clinician. Saving the tissue or photographing it can help doctors identify what it is.
Key Questions Answered
What is a decidual or endometrial cast?
It is the uterine lining shed in one intact piece instead of breaking apart during a period. The tissue is often shaped like the uterus. The medical name for the condition is membranous dysmenorrhea.
What was unusual about this case?
The condition is often linked to hormone use, especially progesterone-containing products. This 36-year-old patient had used no hormonal contraception, fertility drugs or herbal remedies, and her hormone tests were normal.
How did doctors confirm the diagnosis?
They ruled out pregnancy with a negative test, used ultrasound to exclude polyps, fibroids and other lesions, and examined the tissue under a microscope. It showed pre-decidualized endometrial tissue consistent with membranous dysmenorrhea.
Is passing a decidual cast dangerous?
It is usually not considered a sign of a serious problem and has not been known to cause infertility, according to Cleveland Clinic. Because miscarriage and ectopic pregnancy can cause similar symptoms, a medical evaluation is important.
How was the patient treated?
Doctors removed the cast with forceps, which relieved her pain right away. She then received three monthly leuprolide injections plus pain medication and had no recurrence over three cycles, though one case cannot prove the treatment works.
Published by Medicaldaily.com
