Bladder leiomyosarcoma: report of three cases

Leiomyosarcoma of the urinary bladder: a clinicopathological study of 34 cases

Background

Leiomyosarcomas of the urinary bladder (LMS-UB) are rare, usually aggressive neoplasms. Owing to their rarity, only a limited number of cases with clinical follow-up information have been published. There is no current consensus on LMS-UB grading, and it is unknown whether the widely accepted Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) and National Cancer Institute (NCI) grading systems of soft-tissue sarcomas are applicable to LMS-UB.

Methods

The authors studied 34 well-characterised LMS-UB and compared the prognostic power of the FNCLCC and NCI systems with that of one published grading scheme for LMS-UB (Mayo). All available slides from 34 LMS-UB were retrieved and evaluated with regards to degree of differentiation, mitotic rate/10 high-powered fields (HPF), and % necrosis. Cases were graded using published criteria for the FNCLCC, NCI and Mayo schemes. Follow-up information was obtained.

Results

The tumours occurred in 17 females and 17 males, ranging from 31 to 91 years (median 65), and measured 2–12 cm in size. One tumour was well differentiated, 17 tumours were moderately differentiated, and 16 tumours were poorly differentiated. Mitotic rates ranged from 1 to >30/10 HPF (median 12/10 HPF), and tumours showed 0–60% necrosis (median 25%). FNCLCC grades were 1 (3), 2 (12) and 3 (19). NCI grades were 1 (2), 2 (11) and 3 (21). Mayo grades were low (7) and high (27). FNCLCC and NCI grades were identical in 23/34 cases (68%). Four cases were FNCLCC/NCI grade 2 or 3 and Mayo low-grade. Clinical follow-up was available for 25 of 34 patients (74%). Clinical follow-up of ≥12 months was available for 17 of these 25 cases (68%) with a median follow-up duration of 52 months (range 12–120 months). Adverse outcome was seen in nine of these 17 patients (53%). Seven of the eight cases (88%) with a clinical follow-up duration of <12 months died of their disease. Overall, adverse outcome was documented in 16 of 25 (64%) cases. Metastatic disease was seen in 13 of 25 (52%) cases, with the lungs being the most common site of metastasis (62%). Adverse outcome was noted in 15 of 23 (65%) of FNCLCC grade 2 or 3 LMS-UB, as compared with zero of two (0%) FNCLCC grade 1 tumours (p=0.15), in 15 of 23 (65%) NCI grade 2 or 3 LMS-UB, versus zero of two (0%) NCI grade 1 sarcomas (p=0.17) and in 13 of 20 (65%) Mayo high grade LMS-UB, as opposed to two of five (40%) low-grade lesions (all results not statistically significant).

Conclusions

The authors conclude that LMS-UB occurs in older adults of either sex and is characterised by aggressive behaviour, with adverse outcome in >60% of cases. Certain advantages of the FNCLCC system may support its more widespread adoption for future studies.

SMOOTH MUSCLE NEOPLASIA OF THE URINARY BLADDER WALL IN THREE DOGS

Smooth muscle origin neoplasia of the urinary bladder wall is rare in dogs. This report describes the ultrasonographic features of two bladder wall leiomyomas and one bladder wall leiomyosarcoma. All three dogs had a single, smoothly marginated, round, hypo to mixed echogenicity intraluminal mass in the urinary bladder. Based on color Doppler examination of the masses, there was no visible blood flow.

Smooth muscle neoplasms of the urinary bladder: a clinicopathologic comparison of leiomyoma and leiomyosarcoma

We report the clinicopathologic, immunohistochemical, and DNA ploidy findings of 18 leiomyosarcomas of the urinary bladder. In addition, we compare these malignant smooth muscle tumors with 10 cases of urinary bladder leiomyoma. The 14 male and four female patients with leiomyosarcoma ranged in age from 25 to 88 years (mean 64 years). The tumors ranged from 3.0 to 15.0 cm (mean 7.1 cm) in greatest dimension and were moderately to highly cellular, consisting of interlacing fascicles of spindled cells with mild to marked nuclear atypia. Coagulative tumor necrosis was identified in 14 cases (78%), and mitotic activity ranged from 1 to 42 mitotic figures (MF) per 10 high power fields (HPF) (mean 12 MF/10 HPF). Tumors were classified as either high-grade (12 cases) or low-grade (six cases) based on nuclear atypia, mitotic activity, and tumor necrosis. Actin positivity was present in 15 tumors (83%), and desmin immunoreactivity was present in seven tumors (39%). All cases were negative for epithelial markers and S-100. Proliferative activity, as assessed by MIB-1 staining, ranged from 0.1% to 51.4% (median 9.1%). Seven (39%) of the leiomyosarcomas were DNA aneuploid, eight (44%) were tetraploid, and three (17%) were diploid. Five patients underwent radical cystoprostatectomy, one radical cystectomy, seven had partial cystectomy, two underwent pelvic exenteration, and three patients had transurethral resection only. Follow-up information was available on all 18 cases and ranged from 2 to 68 months (mean 22 months). Of the 12 patients with high-grade tumors, six (50%) died of disease from 2 to 20 months (mean 7 months) after diagnosis and three patients (25%) are alive with metastatic tumor. Two of the six patients with low-grade leiomyosarcoma died of tumor, 61 and 68 months after diagnosis. There were five male and five female patients with leiomyoma ranging in age from 22 to 78 years (mean 61 years). The tumors ranged from 0.5 to 4.5 cm (mean 1.6 cm) in greatest dimension, were well circumscribed, and had low cellularity. Mitotic activity, necrosis, and cellular atypia were absent, and the tumors were strongly positive for both actin and desmin. MIB-1 staining ranged from 0% to 3.8% (median 0.8%). Seven (87.5%) of the leiomyomas were DNA diploid or near-diploid and one (12.5%) was DNA aneuploid. Six patients were treated with transurethral resection and four with partial cystectomy. All 10 patients were alive at the last follow-up (mean follow-up 75 months), and no tumor recurred or metastasized. Our study shows that low-grade leiomyosarcomas are capable of malignant behavior, and high-grade leiomyosarcomas appear to behave more aggressively than low-grade tumors. In addition, the diagnosis of urinary bladder leiomyoma should be reserved for noninfiltrative smooth muscle tumors lacking mitotic activity, cytologic atypia, and necrosis.

[Leiomyosarcoma of the urinary bladder]

We report a case of bladder leiomyosarcoma treated at our department. We review the published papers about this entity. We emphasize the low incidence of that pathology and the lack of consensus about treatment.