Imperforate hymen mimicking acute appendicitis in an adolescent woman: a rare presentation

Imperforate hymen is a rare congenital malformation of the female genital tract. The condition poses several diagnostic challenges owing to its low incidence and often atypical presentation. Classical symptoms include amenorrhoea and cyclical abdominal pain. Delayed diagnosis leads to potentially irreversible and lifechanging sequelae including infertility, endometriosis and renal failure. A premenarchal 13-year-old girl with a background of chronic constipation presented with symptoms mimicking acute appendicitis. The underlying cause was imperforate hymen and retrograde menstruation. The diagnosis was made during diagnostic laparoscopy. As with this patient, pre-existing symptoms are often troublesome long before the true diagnosis is made. This case report highlights the importance of recognising imperforate hymen as a potential cause of acute abdominal pain in premenarchal adolescent girls. The clinical picture may present as right or left iliac fossa pain. Early identification reduces the risk of adverse complications and avoids unnecessary and potentially harmful interventions.

congenital disorders, surgery, general surgery, paediatric surgery, obstetrics and gynaecology

Imperforate hymen is an unusual but important cause of acute abdominal pain in adolescent girls. This case describes a diagnosis of imperforate hymen mimicking acute appendicitis and illustrates the potential delays that often ensue prior to definitive management. It also highlights the subtle, nonspecific symptoms that are integral to forming an appropriate diagnostic workup. Although a rare occurrence, imperforate hymen is the most common obstructive congenital malformation of the female genital tract.1 It has an estimated incidence of 0.01%–0.05% or 1 in 1000–2000 live female births2; and with the exception of a few familial cases, the vast majority is isolated findings caused by sporadic anomalies.3 4 The adolescent woman ultimately presents with classical symptoms of primary amenorrhoea and cyclical abdominal pain; however, a number of patients also present atypically with chronic constipation,5 recurrent urinary tract infections, acute urinary retention and hydronephrosis with renal failure.6 If left untreated, adverse complications such as secondary endometriosis, adhesions, renal failure and infertility may arise.7 This case demonstrates how a high index of suspicion should be reserved for all premenarcheal adolescent girls presenting with an acute abdomen, especially in patients with suspected appendicitis who are yet to begin menses and give a history of cyclical abdominal pain, urinary symptoms or chronic constipation. Case presentation A premenarchal 13-year-old girl, accompanied by her parents, presented to the paediatric emergency department with a 2-day history of worsening migratory right iliac fossa pain. Her pain was severe and associated with anorexia, nausea and fever. She had a background of chronic constipation, which had recently returned, causing problematic ongoing episodes of cramping lower abdominal pain. She was otherwise fit and well and had an unremarkable birth and developmental history. She had not yet reached menarche, which was appropriate in accordance to her mother’s menarcheal age, and she was not sexually active. The worsening abdominal pain was of gradual onset, nonradiating and constant. Physical examination revealed a mildly distended abdomen, in keeping with the history of chronic constipation, and generalised tenderness localising to the right iliac fossa with a positive Rosving’s sign. There were also clinical signs of right lower quadrant peritonism with guarding and rebound tenderness on deep palpation. She denied any dysuria or urinary frequency. Concluding history and examination ruled out the need for perineal examination. Blood tests revealed raised inflammatory markers with a white cell count of 9.6×109/L and C reactive protein (CRP) of 68.4 mg/L. Urine dipstick was (3+) positive for leucocytes. A clinical diagnosis of acute appendicitis was made, and the patient was booked for a diagnostic laparoscopy and appendicectomy to take place the next day on the emergency list. Intravenous fluids, antibiotics and oral analgesia were administered overnight on the paediatric ward. The patient presented with characteristic symptoms in-keeping with acute appendicitis and continued to have abdominal tenderness despite analgesia. Based on history, clinical examination and raised biochemical markers of infection, diagnostic imaging studies such as abdominal ultrasound and x-ray images were not carried out to avoid delay in definitive management. Diagnostic laparoscopy the following morning revealed the appearance of a macroscopically normal appendix. However, the presence of brown chocolate-like fluid and dense adhesions (figure 1) within the pelvis became immediately apparent. Significant dilatation of the uterus (figure 2) and fallopian tubes with no evidence of rupture was also noted. The Gynaecology Consultant was asked to kindly join the team in theatre to review the situation. Subsequent perineal examination revealed a bulging membrane indicative of an imperforate hymen. While the patient remained under general anaesthetic, a collaborative discussion took place between the parents and the General and Gynaecology Consultant Surgeons. The intraoperative findings were explained, and further probing revealed a recent flare up of the patient’s constipation issues that were thought to be cyclical in nature. The parents also noted that recently she would have episodes of “sitting on the toilet for hours in pain”. They gave consent for the Gynaecology Consultant to perform an incision of the hymen and drainage of haematometra (figure 3), which drained 800 mL of viscous old blood from the vaginal introitus. Investigations Blood samples, including full blood count, C- reactive protein, urea and electrolytes were taken. The white cell count (WBC) of 9.6×109/L, CRP of 68.4 mg/L, and urea and electrolytes were within normal limits. Urine analysis showed the presence of leucocytes (3+), with a trace of protein and blood. Vital signs were within normal range and she remained afebrile throughout the admission. A combination of history, examination and laboratory results led to the clinical diagnosis of acute appendicitis. Imaging is reserved for equivocal cases where clinical features are inconclusive and, in this case, we pre-empted an abnormal ultrasound scan. Ultrasound also has a limited sensitivity and specificity for detecting appendicitis, and commonly the appendix is unable to be visualised. Furthermore, although superior, CT scans are impractical in the paediatric population due to the ionising radiation exposure. The ongoing severity of the abdominal pain despite analgesia and raised inflammatory markers resulted in the decision to undergo a diagnostic laparoscopy and appendicectomy without a preoperative scan. In retrospect, prior imaging would not have influenced our clinical decision, since the patient was demonstrating pain secondary to an underlying intra-abdominal pathology that would inevitably have required a diagnostic laparoscopy; regardless of imaging findings. Differential diagnosis The differential diagnosis of acute abdominal pain in premenarchal adolescent women is reasonably broad. Common underlying pathologies can range from gastrointestinal, gynaecological and urological causes. The accurate diagnosis and timely management of important surgical emergencies are imperative in these patients. The patient denied the commencement of menses and was not sexually active. This ruled out several possible gynaecological causes such as ectopic pregnancy, dysmenorrhoea, mittelschmerz and pelvic inflammatory disease. Although ovarian torsion was plausible, it is extremely rare among the paediatric population and generally occurs in menstruating women of childbearing age8; with a reported prevalence of 4.9 per 100 000 women.9 Urine dipstick showed the presence of leucocytes (3+), with a trace of protein and blood, and was negative for pregnancy. She denied dysuria or urinary frequency, and blood tests were indicative of a normal renal function. The clinical findings on abdominal examination were out of proportion to an attributing urinary tract infection. The positive urine dipstick most likely indicated a mildly obstructed renal outflow tract, secondary to a dilated uterus encroaching on ureteric organs. Other possible urological conditions such as renal colic caused by a nephrolithiasis were clinically ruled out due to the nature of the abdominal pain, which was gradual onset, migratory and non-radiating. There were no signs or symptoms suggestive of gastrointestinal obstruction secondary to volvulus, intussusception or adhesions. The patient denied any recent viral infections or coryzal symptoms and was not displaying persistently high temperatures, which would be suggestive of mesenteric adenitis. At initial presentation, the history of chronic constipation was not thought to be a correlation to the acute clinical picture; the red herring being the longstanding history of constipation since childhood. The recent flare of the patient’s constipation, with new cyclical episodes of abdominal pain, was overlooked. Imperforate hymen can lead to chronic constipation as a result of accumulating menstrual blood, causing a localised pressure effect on the rectum. Treatment Initial management included supportive care with 500 mL intravenous Plasma-Lyte 148, ibuprofen, paracetamol, oral morphine for pain control and 4 mg intravenous ondansetron for nausea. The presumptive diagnosed acute appendicitis was treated with 10 mL oral coamoxiclav two times per day. She was kept nil by mouth overnight and underwent a diagnostic laparoscopy the next morning on the emergency list. Intraoperatively, once the underlying diagnosis of imperforate hymen had been established, the General Surgeons performed a washout (figure 4) of the intra-abdominal blood. After a discussion between the surgical consultants and the patient’s parents, consent was obtained to perform a hymenotomy, and the patient was repositioned from supine into the lithotomy position. A 2 cm elliptical incision was made into the hymenal membrane, which subsequently drained 800 mL of thick brown altered blood. The peripheral hymenal remnants were then oversewn with 2/0 vicryl rapide to avoid postoperative reclosure and bleeding. After the intraperitoneal wash out was complete, an intra-abdominal Robinson drain was left in situ. The patient was then returned to the paediatric ward for observation and further administration of antibiotics and analgesia was done. Outcome and follow-up Postoperatively, the patient required paracetamol, ibuprofen and oral morphine for pain control. Intravenous doses of cefuroxime and metronidazole were given for 3 days. The intra-abdominal Robinson drain produced 150 mL of haemoserous fluid and was removed 2 days later. She was eventually discharged home 3 days after the procedure, with a 5-day course of oral coamoxiclav. Two days after discharge, the patient underwent an outpatient pelvic ultrasound to exclude renal, pelvic or other vaginal anomalies. The scan was reported as normal with no observed abdominopelvic abnormalities. An outpatient MRI scan carried out 3 weeks later also demonstrated normal anatomy. The patient was followed up in the gynaecology outpatient department 8 weeks later, where the imaging findings were relayed. After further discussion about the condition and the events that had occurred, the patient was informed that she should not expect any difficulties in the future, but her general practitioner could make a referral if there were any problems. Physical examination revealed adequate hymen patency. Overall, she had a satisfactory outcome and was discharged from the outpatient gynaecology clinic. She has experienced normal menstruation since the procedure and reported no further other issues. The gynaecology team recommended that in the event of dysmenorrhoea or pelvic pain in the future, she should have a low threshold for commencing the contraceptive pill, as this may be suggestive of endometriosis.

Development of the female genital tract begins at 3 weeks of embryogenesis and comprises a complex series of stepwise events, involving cellular differentiation, migration, fusion and canalisation. Failure to achieve these processes results in congenital anomalies of the hymen and vagina. The consequential structural disruption interferes with normal vaginal function and leads to potential complications and adverse long-term sequelae.10 The hymenal membrane is formed by fusion of the paramesonephric ducts and urogenital sinus.11 The membrane acts as an occlusive septum at the level of the vaginal introitus, and after degeneration of the central epithelial cells, the hymen usually perforates before birth. However, imperforate hymen persists when the remnant of tissue fails to rupture, allowing the progressive accumulation of uterine and vaginal secretions.3 Although a rare malformation of low incidence, imperforate hymen is the most common obstructive lesion of the female genital tract. It is an important and often overlooked gynaecological anomaly that can cause an acute abdomen in premenarchal adolescent girls.12 The condition is typically asymptomatic until menarche, when patients present between 13 and 15 years of age with vague or atypical symptomatology. At the commencement of menses, amassing blood and mucus collect within the vagina, uterus and eventually fallopian tubes with each successive cycle. This results in haematocolpos, haematometra and haematosalpinx, respectively; collectively known as haematometrocolpos.13 Although some familial cases have been reported, the condition is considered a sporadic malformation of unknown cause, with no proven aetiological genetic markers or mutations.12 Imperforate, microperforate, septate and cribriform hymens are some of the anatomical variants described in the literature. The severity of presenting symptoms pertains to the degree of hymenal obstruction, which may be partial (incomplete fenestration) or complete.10 The condition may be identified at various stages, including infancy, adolescence and adulthood. Clinical presentations vary according to each age group and pattern of anatomical variance. It is possible to detect imperforate hymen on prenatal scans or during the neonatal period when a bulging introitus noted.12 If the diagnosis is not made in the newborn, the mucus is reabsorbed, and the child remains clinically quiescent until menarche.10 Where there is incomplete fenestration of the hymenal opening; however, cases will often go undetected until adulthood. Adult patients are typically investigated by the gynaecology and fertility services due to failure to achieve coitus, dyspareunia, malodorous vaginal discharge, tubo-ovarian abscess formation or infertility.10 Imperforate hymen becomes a surgical emergency when patients present with sepsis secondary to infected obstructed blood or marked distension of the female genital tract. This may result in acute urinary retention or reproductive organ rupture and peritonitis.10 Definitive management involves surgical repair under general anaesthesia. An elliptical incisions into the hymen is carried out, followed by evacuation of obstructed contents. Extrahymenal tissue is then sutured to prevent postoperative bleeding or adhesional reclosure and recurrence.10 Abdominal pain is the most common presenting report;14 however, patients often demonstrate a range of clinical manifestations involving multiple organ systems, including primary amenorrhoea with normal secondary sexual characteristics, chronic constipation, back pain, recurrent urinary tract infections, voiding dysfunction,5 renal failure with hydronephrosis15 and acute urinary retention,7 abdominal mass or fever.2 Delayed diagnosis results in protracted and troublesome symptoms, which may eventuate serious life-changing complications with significant morbidity, such as infertility, endometriosis and kidney disease.7 A recent systematic review by Lee and colleagues found that 93.3% of patients had a delayed diagnosis of imperforate hymen. The authors went on to describe abdominal pain as the most common presenting symptom (54.2%), followed by urinary retention (20%), abnormal menstruation (14%), dysuria (9.7%) and urinary frequency (5.1%).3 Alternatively, imperforate hymen may be an incidental finding, identified on routine examination or imaging studies for other clinical reasons. Posner and Spandorfer described a bimodal distribution of age of diagnosis, in which they found that 57% of girls were not diagnosed until over 8 years of age. Of the 43% diagnosed in the younger age category, 90% of cases were incidental findings, whereas 100% of girls in the older population presented with nonspecific abdominal or urinary symptoms.16 A retrospective observation study carried out by Lazanyi and Grover in 2019 highlighted the diagnostic challenges associated with imperforate hymen. Over an 18-year period, they identified 27 cases at a tertiary paediatric hospital. The mean age of presentation was 12 years, and 80% of these patients presented numerous times (up to five times per year) before the diagnosis was reached.14 Another study by Lui and colleagues also found the mean age of presentation to be 12 years, with 86% of cases initially presenting to the emergency department with lower abdominal pain (60%), acute urinary retention (53%) and constipation (20%). The authors went on to report that longer hospital stays were observed for the delayed diagnosis group (mean length of stay 4.2 days) compared with the group diagnosed in the emergency department at initial presentation (mean length of stay 1.9 days).17 Amponsah-Manu et al present a case of imperforate hymen with leaking intraperitoneal haematosalpinx. The 12-year old premenarchal patient presented with migratory right iliac fossa pain, which was initially misdiagnosed as acute appendicitis.13 Similarly, Sengupta and colleagues describe a 11-year-old girl with a 2-day history of right iliac fossa pain and elevated CRP.18 In both cases, like many others, inspection of external genitalia was not considered, and preoperative imaging studies were not performed. Both patients proceeded to have an appendicectomy before the underlying cause of imperforate hymen was identified during laparoscopy. This scenario is not unique, as evidenced by Nazir et al in a case series where 3 out of 18 patients presenting with abdominal pain secondary to imperforate hymen underwent a laparoscopic appendicectomy. Furthermore, in another report, a McBurney laparotomy was carried out on an 11-year-old adolescent girl with suspected appendicitis until the intraoperative findings revealed a normal appendix and haemoperitoneum secondary to imperforate hymen.19 Diagnosis of imperforate hymen can be made on pelvic examination when the intact hymenal membrane is visualised as a bulging mass at the vaginal introitus.10 However, this assessment it is not typically carried out in the absence of obvious gynaecological history and is, therefore, infrequently performed as part of the routine clinical workup in adolescent girls with acute abdominal pathology. One case report details a patient with suspected acute appendicitis who refused pelvic examination and was subsequently booked for an appendicectomy. However, the operation was not performed after a preoperative transabdominal ultrasound scan revealed an echogenic mass with vaginal dilatation.20 There are several supporting citations where patients with undiagnosed imperforate hymens presenting with right iliac fossa pain and raised inflammatory markers are booked for laparoscopic appendicectomies. However, in these case reports, the use of preoperative ultrasound imaging, to identify the underlying imperforate hymen, prevented unnecessary intra-abdominal surgery.16 20 We present a rare case of imperforate hymen mimicking acute appendicitis, secondary to retrograde menstruation in a premenarchal adolescent girl. This report highlights that although an uncommon congenital anomaly, when present, imperforate hymen poses considerable diagnostic uncertainty and is an important cause of acute abdominal pain. A review of the literature identified several case reports and studies demonstrating the difficulty in identifying imperforate hymen, and the numerous patients whose diagnoses were missed or delayed. The general consensus calls for an improvement in medical education on the natural history of imperforate hymen and the commonly associated symptoms; an incorporation of external genitalia inspection on clinical examination and the undertaking of preoperative ultrasound imaging for this specific cohort of patients. For all adolescent women presenting with acute abdominal pain, therefore, a systematic approach must be used, with consideration to underlying abnormalities of reproductive organ development and function. Furthermore, imperforate hymen should always be suspected when there is a discrepancy between Tanner stage (stage IV or V) and menarcheal status.21

Fortunately, the patient in this case report had a satisfactory outcome with no lasting complications. The presence of blood and adhesions in the intraabdominal cavity demonstrated that retrograde menstruation had taken place. The blood acted as a peritoneal irritant, manifesting as ‘migratory’ right iliac fossa pain and mimicking acute appendicitis. Future cases should consider that menarche generally occurs 2–2.5 years after breast budding. In a 13-year-old premenarchal patient presenting with the aforementioned clinical picture, a detailed sexual development history with tanner staging may have signposted the correct diagnosis. Furthermore, while genital examination was not indicated in this case, it is surprising that a palpable uterus was not detected on abdominal examination. This may be attributable to the fact that the patient presented with a background of chronic constipation associated with abdominal bloating and pain. The accumulated intrauterine blood was washed out intraoperatively to manage the peritoneal irritation and abdominal pain and reduce the risk of postoperative infection. The hypothesis that retrograde menstruation plays a key role in the pathogenesis of endometriosis was first described by Sampson.22 The patient may, therefore, be at an increased risk of developing endometriosis in the future. However, the intra-abdominal washout (figure 4) and adhesiolysis (figure 1) performed during the diagnostic laparoscopy are expected to reduce the prospect of future endometriosis progression. This case report demonstrates the complex and variable nature of symptomology associated with imperforate hymen in premenarchal adolescent women. Its relatively low incidence and nonspecific or atypical symptomology pose several diagnostic challenges that can lead to misdiagnosis at initial presentation. It may indeed even mimic acute appendicitis. Review of the literature delivered several case reports and retrospective observational studies relaying the frequency of atypical presentations, missed diagnoses and erroneous interventions; however, only a small number of those describe the rare clinical presentation of imperforate hymen mimicking acute appendicitis. This report intends to improve the education and awareness of the various symptomologies of imperforate hymen and to reduce the risk of unnecessary investigations, diagnostic delay and potentially harmful interventions: factors which are likely to result in poor patient outcomes, significant patient morbidity and protracted hospital stays worsening the financial burden to healthcare systems. Learning points. Despite imperforate hymen being a rare and difficult-to-diagnose congenital malformation, it is an important cause of acute abdominal pain in premenarchal adolescent girls. In unique cases, imperforate hymen may mimic acute appendicitis and delay diagnosis. During abdominal examination, clinicians must examine carefully for a palpable uterus. Surgeons should have a high index of suspicion in patients with abdominal bloating, delayed menses or asynchronous Tanner stages and consider imperforate hymen in their differential diagnosis. While genital examination may not be indicated clinicians must consider taking a detailed sexual development history, which may indicate an alternative diagnosis and facilitate more specific imaging and surgical intervention. In particular, a background of cyclical abdominal pain, urinary symptoms or chronic constipation should be explored, and examination of external genitalia, as well as routine abdominal ultrasound should be carried out as part of a full assessment. Early diagnosis is essential to prevent potentially irreversible complications and lifechanging sequelae. Footnotes Collaborators: Mr Tom Setchell Consultant Obstetrician and Gynaecologist Contributors: VRR: second surgeon and writer of the manuscript. MI: primary surgeon and reviewer of the manuscript. SP: primary caregiver, general surgery consultant, and reviewer of the manuscript. TS: primary caregiver, obstetrics and gynaecology consultant. GP: corresponded with the patient to obtain consent and patient perspective. All authors reviewed and amended the manuscript draft. The supervising author SP supported the authors and approved the final manuscript for submission. Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors. Competing interests: None declared. Patient consent for publication: Parental/guardian consent obtained. Provenance and peer review: Not commissioned; externally peer reviewed.

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