Introduction: Leiomyomas of bladder is a relatively rare condition. About 0.43% leiomyomas account for all of bladder tumors. Reported about 250 cases of leiomyoma of the bladder have been previously reported in scientific literature currently. The incidence of leiomyoma of the bladder is approximately three times higher in women than in men because they believed on theory of hyperestrogenism cause growth of leiomyomas. Predominantly in young and adult females. Mostly patients presented with nonspecific urinary symptoms or pelvic pain.
We present a case report about pregnant women who presented with abdominal mass in pregnancy and our initial diagnosis was ovarian tumor in pregnancy.
Case Report: A 28 years old presented with lower abdominal discomfort and abdominal mass, which was progressively increasing in size for the past 4 months. She does not have any disturbance in her menstrual cycle, constitutional symptoms or any compressive symptoms such urinary or bowel symptoms.
On general examination, she was a small-framed lady. Per abdomen examination revealed a mass arising suprapubically up to the size of 22 weeks gravid uterus, with hard in consistency, smooth surface, fixed, and no evidence of ascites. Bimanual examination confirmed a hard pelvic mass which was separated from the uterus, the uterus was 6/52 in size and no adnexa or POD mass was appreciated.
Bedside ultrasound revealed a huge mass located anterior to the uterus with mixed solid cystic appearance, measuring 14 x 9.4 cm. The uterus was pushed posteriorly by the mass, and it measured 7.5 cm x 4.4 cm. No adnexal mass noted, ascites or hydronephrosis noted. Ca125 was 141.2 IU, and the other tumour markers were normal.
The initial diagnosis was pedunculate fibroid with a differential diagnosis of solid ovarian tumour. She then underwent CT scan, thorax, abdomen, pelvis and the result was suggestive of large pelvic mass arising from right hemipelvis measuring 9.6 x 13.2 x 14.5 cm, with normal uterus and left ovary. She was counselled for exploratory laparotomy + cystectomy KIV salphingo-oopherectomy with a diagnosis of solid ovarian tumour.
However, when she was admitted for the operation, she was found to be pregnant. Hence the operation was postponed to 14 weeks of gestation. Reassessment prior to operation noted that the mass was increasing in size; 26/52 of gravid uterus.
Intraoperatively, there was a huge solid mass noted arising from the bladder, with lobulated surface, dilated blood vessels, and adhered to the anterior abdominal wall. The uterus was normal, 14/52 size, and was pushed posterolaterally. Both ovaries were normal. The urology team was called in, and proceeded with debulking of bladder tumour and partial cystectomy. Post operatively, she was put on suprapubic catheter and continuous bladder drainage, and both were removed after 2 weeks of surgery.
HPE of the bladder tumour confirmed leiomyoma of the bladder, and the bladder wall tissue revealed fibromuscular tissue mixed with adipose tissue.
Currently, she already 34 week period of amenorrhea, under our antenatal and urology follow up. She was well throughout the pregnancy.
Discussion: The main reason we performed surgery on this patient because of rapidly growing pelvic mass which is highly suspicious of malignancy.
Our preoperative diagnosis was solid ovarian tumour which was most likely germ cell tumour (dysgerminoma or teratoma) which commonly presents in pregnancy. The diagnosis was made based on the clinical and imaging finding (ultrasound and CT scan) but without raised tumour marker level. Intra-operatively, the extra-vesical urinary bladder fibroid was diagnosed.
Bladder leiomyomas can be extra-vesicle, intramural or endo-vesicle. The commonest type, endo-vesicle comprised of 63%, followed by extra-vesicle, 30% of cases and the least common type is the intramural, represent 7% of cases. Most of the bladder leiomyomas asymptomatic except endo-vesicle type which commonly presents with urinary symptoms.
The aetiology of these tumours remains unknown. Some authors proposed that leiomyomas may arise from chromosomal abnormalities, hormonal influences, bladder musculature infection, perivascular inflammation. The female predominance during reproductive age suggests that hormonal influence which similar like uterine fibroid hypothesis (oestrogen dependant).
Bladder leiomyomas may be asymptomatic but usually present with obstructive symptoms (49%), irritative symptoms (38%) and haematuria (11%).
Although Magnetic Resonance Imaging (MRI) able to differentiate mesenchymal tumours from the commoner type, transitional cell tumours and the malignant leiomyosarcoma, but the cystoscopy and biopsy of the lesion still necessary to confirm the histo-pathology prior to exploration.
In this case, our patient had no urinary symptoms, mainly because the mass is extra-vesical type. As a result, MRI and cystoscopy was not performed prior to surgery. Perhaps pre-operative MRI is able to help us with the diagnosis, but the final diagnosis still depends on the intra-operative findings and the histo-pathological examination.
Conclusion: In conclusion, bladder fibroid should be considered as one of the differential diagnosis in pregnant patient who presents with rapid growing solid pelvic mass.
References:
Erdem, H., Yildirim, U., Tekin, A., Kayikci, A., Uzunlar, A. K. & Sahiner, C. (2012). Leiomyoma of the urinary bladder in asymptomatic women. Urology Annals, 4(3), 172-174. doi: 10.4103/0974-7796.102667
Park, J. W., Jeong, B. C., Seo, S. I., Jeon, S. S., Kwon, G. Y. & Lee, H. M. (2010). Leiomyoma of the urinary bladder: a series of nine cases and review of the literature. Urology, 76(6), 1425-1429. doi: 10.1016/j.urology.2010.02.046