Teaching Case

31-year-old woman, 21 weeks pregnant, with history of recurrent urinary tract infection.

Repeat ultrasound at our institution showed the foetus in vertex position, with the placenta located anteriorly along the fundus, a few centimetres away from the bladder (Figure 1). A soft-tissue mass measuring 4.5 x 1.9 x 5.3 cm was seen within the bladder lumen, continuous with and arising from the posterior bladder wall (Figure 2). Colour Doppler revealed flow within this mass (Figure 3).

Further evaluation with MRI redemonstrated the bladder mass, which was hypointense on
T2-weighted images (Figure 4) and isointense to the bladder wall on T1-weighted images (Figure 5). The mass appeared to be invading the roof of the bladder, with suspected extension through the full thickness of the bladder wall into the perivesical fat. However, there was a very thin fat plane separating this mass from the myometrium of the uterus. Staging with pelvic MRI, abdominal ultrasound, and chest X-ray was negative for metastatic disease.

A. In the developed world, the most common type of bladder cancer is transitional cell carcinoma, accounting for over 90% of cases [1]. The risk of squamous cell carcinoma is increased with chronic bladder irritation (as from recurrent urinary tract infections or indwelling catheters) and Schistosoma haematobium infection. To the best of our knowledge, only two other cases of nonbilharzial (i.e. not related to schistosomiasis) squamous cell carcinoma of the bladder during pregnancy have been described in the English language literature [2, 3].
B. The most common clinical finding of bladder cancer is painless haematuria, either
gross or microscopic. 70% of women present with haematuria, which may be mistaken for
urolithiasis or vaginal bleeding in pregnancy [1]. Irritative urinary symptoms are the next most common presentation; these may also occur in normal pregnancies and confounding conditions such as urinary infection [1, 4]. More advanced disease may present with symptoms of pelvic or flank pain, ureteral or lymphatic obstruction, or metastases to the regional lymph nodes, liver, lungs or bones [1].
C. Ultrasound is useful in screening and evaluation of bladder malignancy in pregnancy, as there is no radiation risk to the fetus. Lesions greater than 2 cm can be reliably visualized [2]. Cystoscopy is the main investigation for characterizing bladder lesions; it is generally well tolerated during pregnancy [1]. MRI is used to stage the extent of disease and assess for abdominal and pelvic metastases [5]. In pregnancy, a modified metastatic workup includes chest radiography and a bone scan [1].
D. Low-risk cancers are treated by transurethral resection at any gestational age [6] and followed by cystoscopy. Prognosis is generally good. Intermediate- and high-risk cancers are treated by complete resection, to be followed by repeat resection and intravesical chemotherapy or immunotherapy after delivery, which may be planned sooner with high-risk cancers [7, 8].
Invasive bladder cancer (T2-T4) carries a poorer prognosis. Management is individualized as few such cases are reported in the literature, but includes termination for first and second trimester pregnancies, and Caesarean section with radical cystectomy and urinary diversion after fetal viability at around 28 weeks of gestation for more advanced pregnancies [6]. In our case, the patient also received adjuvant chemotherapy and radiation.
E. In conclusion, although bladder cancer in pregnancy is uncommon, it is important to examine the bladder on prenatal ultrasound to screen for evidence of malignancy, as symptoms may overlap with those of conditions common in normal pregnancy, and a high index of suspicion helps achieve a prompt diagnosis. Delay in treatment directly correlates with a poorer prognosis [5].