Most bladder tumors are epithelial and particularly urothelial, non-urothelial neoplasms occur very rarely in the bladder and usually present a diagnostic challenge. In the present study, to the best of our knowledge, UBH is mostly congenital malformation of capillaries and blood vessels, non-urothelial neoplasms are extremely rarely reported clinically, accounting for only 0.6% of all urinary bladder tumors[3–4].
Although it can occur in all age groups, the most often age group is under 30. In the review of literature most of the bladder hemangioma are solitary (66%), varying from few millimeters to 10 cm in diameter with a predilection for the dome, posterior wall, and trigone of the bladder and so it has increased the diagnostic challenge of intramural tumors of the bladder[5]. Multiple bladder hemangiomas occasionally coexist with cutaneous hemangioma, varicose veins, or are associated with one of two conditions: Sturge-Weber syndrome and Klippel-Trenaunay-Weber syndrome, predisposing to their development. For this reason, systemic evaluation in these patients is highly recommended[6–7].
UBH are mostly congenital benign tumor formations of angiogenesis. Nevertheless, several studies have confirmed increased risks of developing soft tissue tumors in relation to radiation therapy for cancer[8–9]. The predominant clinical symptom of UBH is painless recurrent, isolated gross macroscopic hematuria with or without irritative urinary symptoms and abdominal pain[10]. However,hypovolemic shock can be present in cases with massive hemorrhage. Hydroureteronephrosis can occur as a result of ureteric obstruction by the mass, and a hematoma can obscure the mass in the bladder when there is massive bleeding[11].
Here, we took a thorough English literature review focusing on UBH published up to January 2019 and identified overall 16 cases published from 2010 to 2019 were obtained after strict selection (Table 1)[5–6, 9, 12–22]. Included our two cases, they occurred in a wide range of ages from 2 to 85 years (mean 27.8), with median age 18 years, and the male to female ratio was 0.8 with no gender predominance. It was typical with respect to size with lesions ranging from 1.0 cm to 7.0 cm in diameter, although the characteristic of multiplicity was not usual. In our two cases, systemic evaluation of our patients was grossly normal, with no cutaneous hemangioma or palpable scrotal varicocele.
Table 1
Literature review of the reported cases of Clinico-pathologic Characteristics of hemangioma in the bladder
Ref/year | Case No. | Sex/ Age (y) | Clinical Manifestation | Site | Tumor Size | Pathologic examination | Treatment | Follow-up (mo) |
Kato et al, 4/2000[12] | 1 | F/8 | Gross hematuria, Klippel Trenaunay syndrome | the apex of the bladder | 4 cm | NA | Nd:YAG Laser | NED(10) |
Pratap et al, 8/2007[13] | 2 | M/5 | gross hematuria accompanied by lower abdominal pain | the dome and the posterolateral bladder wall | 5 cm | cavernous hemangiolymphangioma | Partial cystectomy | NED(8) |
Tavora et al, 8/2008[5] | 3 | F/19 | hematuria alone | not mentioned | 1.1 cm | cavernous hemangioma | biopsy | LFU |
4 | M/67 | hematuria combined with pain | not mentioned | 3.2 cm | capillary hemangioma | biopsy | NED(24) |
5 | F/85 | asymptomatic | not mentioned | 2.4 cm | capillary hemangioma | biopsy | NED(4) |
Antonio et al, 6/2010[14] | 6 | F/7 | mild hematuria with clots | supratrigonal lateral and posterior bladder wall | numerous hemangiomas | NA | eletrocautery | NED(6) |
Ashley et al, 10/2010[15] | 7 | F/3 | gross Hematuria | posterior and left lateral bladder wall | 4 cm | Cavernous hemangioma-lymphangioma | Cystoscopic illuminated partial cystectomy | NA |
Takemoto et al, 10/2011[16] | 8 | M/4 | gross hematuria | anterior wall, dome, and right lateral bladder wall | covered about 60% of the bladder | NA | Nd : YAG/ holmium : YAG laser | NED(24) |
Mager et al, 10/2014[17] | 9 | M/46 | disabling lower urinary tract symptoms | Prostate, the seminal vesicle, and the bladder neck | not mentioned | NA | interventional superselective coiling of the arterial feeder | NED(6) |
Jibhkate et al,1/2015[18] | 10 | M/3 | gross hematuria accompanied by lower abdominal pain | the dome of the bladder | 7 cm | Cavernous hemangioma | Partial cystectomy | NED(12) |
Kim et al, 7/2015[6] | 11 | M/4 | intermittent and recurrent painless gross hematuria | the bladder dome and along the lateral aspects | 1.3 cm | Cavernous hemangioma | coagulated with a Holmium laser | NA |
Lahyani et al, 10/2015[19] | 12 | M/60 | macroscopic haematuria | the dome of the bladder | not mentioned | Cavernous hemangioma | partial cystectomy and augmentation cystoplasty | NA |
Lu et al, 2/2016[20] | 13 | M/46 | asymptomatic | the right bladderwall | 1.4 cm | intramural Anastomosing hemangioma | Partial cystectomy | NA |
De et al, 7/2017[21] | 14 | M/2 | persistent gross hematuria | the dome of the bladder | not mentioned | Cavernous hemangioma | Partial cystectomy | NA |
Hu et al, 11/2018[9] | 15 | F/49 | painless hematuria | the superior posterior wall | 1 cm | cavernous hemangioma | transurethral tumor resection | NED(18) |
Syu et al, 1/2019[22] | 16 | M/17 | painless gross hematuria | the superior anterior wall | 3.5 cm | cavernous hemangioma | en bloc resection of the urachus and bladder tumor with opened surgery | NED(24) |
This report | 17 | F/44 | painless gross hematuria | the superior anterior wal | 5 cm | cavernous hemangioma | open radical cystectomy | NED(36) |
18 | F/31 | asymptomatic | the right anterior wall | 6.9 cm | cavernous lymphangioma and hemangioma | laparoscopic partial cystectomy | NED(12) |
NED, no evidence of disease; NA, not available; Nd : YAG, neodymium: yttrium-aluminium-garnet; LFU, lost to follow-up. |
Clinically, imaging tests, such as ultrasonography, pelvic arteriography, computed tomography scan, and magnetic resonance imaging, are useful in defining the extent and location of a hemangioma[2]. The cystoscopic features of a bluish, sessile mass with gross hematuria are highly suggestive of hemangioma. The endoscopic differential diagnostic considerations for pigmented raised lesions include endometriosis, melanoma, and sarcoma. Accurate diagnosis requires confirmation by biopsy[23].
Since it is not commonly seen bladder hemangiomas in the genitourinary tract, it is important for pathologists and clinicians to carefully differentiate it from malignant non-urothelial neoplasms, as they have vital different prognostic features as well as therapeutic strategies[20]. Clinical and radiological examinations are not enough for an accurate diagnosis. Careful histopathological and immunohistochemical studies are required to establish the correct diagnosis. Histologically, bladder hemangiomas can be classified into cavernous, capillary, and arteriovenous types, and nearly 80% were cavernous type, while much less frequent are capillary or arteriovenous types[23]. Bladder hemangiomas are histologically similar to hemangiomas found at other sites and are composed of numerous proliferative capillaries mixed with thin-walled, dilated blood-filled vessels lined with flattened endothelium. The vessels are sometimes thickened by adventitial fibrosis. The histologic depth of a bladder hemangioma may be within the submucosa layer or even extend to the muscular layer or perivesical tissues[5]. Malignant vascular tumor, such as angiosarcoma, is highly aggressive potential with the characterizations of infiltrative growth, clear cytological atypia, high cellularity and poor prognosis. On the contrary, bladder hemangiomas are typically characterized by proliferated of vessel walls with distinct borders and spreading between the normal vasculature, and which lack distinct endothelial atypia or multilayering and with favorable prognosis[23]. The differential diagnosis of a polypoid bladder mass detected in children with painless gross hematuria includes not only hemangioma but also rhabdomyosarcoma, other vascular tumors, inflammatory pseudotumor, leiomyoma, neurofibromatosis, pheochromocytoma, transitional cell papilloma, transitional cell carcinoma, and pseudo tumoral cystitis[25–26].
The treatment options for UBH are varied for individuals with favorable follow-ups. The treatment of patients with a UBH is controversial, and the factors include the size, location and depth of penetration[22]. For small lesions and asymptomatic hemangiomas, surveillance is sufficient. The treatment is only necessary when the lesions threaten the organ function or the patient´s performance status, such as hematuria resulting in anemia, and suspicion of some malignant lesion. Optional treatment strategies include observation, transurethral resection, electrocoagulation, radiation, systemic steroid administration, injection of a sclerosing agent, interferon-a-2 therapy, YAG-laser therapy, and partial cystectomy or complete cystectomy[5, 12, 22]. Transurethral endoscopic surgery resection has become the gold standard for the treatment of small bladder cavernous hemangioma. The risk of uncontrollable bleeding is insignificant when the lesion is small (≤ 3 cm), and follow-ups show favorable outcomes[2, 18]. Biopsy and fulguration do not create significant bleeding and can adequately treat small lesions. Neodymium: yttrium aluminum garnet (Nd : YAG) laser irradiation has become another effective and less invasive treatment option, and it allows complete coagulation of the whole bladder Thickness[16].In cases of > 3 cm masses or multiple tumors or those that extend deep into the bladder, however, a transurethral biopsy or resection of bladder hemangioma is contraindicated because of the iceberg nature of this tumor and the significant possibility of excessive hemorrhage, open resection of the lesion or partial cystectomy are effective[5, 11]. Whereas, A partial cystectomy may reduce storage function, a partial cystectomy and bladder augmentation can preserve storage function, but this treatment may worsen voiding function[19].
Although UBH has a benign course, Postoperative follow-up is mandatory for detecting tumor recurrence or residual disease, such as ultrasonography, CT, and even flexible cystoscopy could be arranged to detect the recurrence[18–19].