Uterus cavernous hemangioma is a rare disease with a wide range of differential diagnosis including arteriovenous (AV) malformation, angiomyoma, and hemangioendothelioma (
1). Also, there is a case report which suggests similarities of imaging between cavernous hemangioma and degenerated myoma (
3). This entity sometimes presents as a uterine mass and sometimes involves myometrium diffusely. Although other studies have reported cases of uterine and cervical cavernous hemangioma, the data about the imaging finding and role of imaging in preoperative diagnosis is still unclear. Due to its rarity, a high clinical suspicion is needed to think about the disease before pathologic findings.
As usual, it is believed that cavernous hemangioma in other parts of the body including the liver, intracranial, and intraosseous are isointense or hypointense on T1 weighted and isointense to hyperintense on T2 weighted MRI depending on the amount of venous stasis in the lesion. They have high signal intensity after contrast enhancement (
4-
6). Obviously, calcification, hemorrhage and necrosis can alter the signals.
Almost always ultrasound is the first modality of imaging in gynecological problems. Careful examination during ultrasound may show a thickened uterine wall with hypoechoic space. Color Doppler imaging usually demonstrates low-velocity flow, or no obvious flow within these spaces. These sonographic features have been specifically described by three case reports with diffuse cavernous hemangioma of the myometrium during pregnancy (
7-
9).
Kobayashi et al. described CT findings of uterine cavernous hemangioma in a 19-year-old woman as a 10 cm mass with numerous small calcifications (
3). They found that in T2 weighted images, high-signal intensity with focal areas of low-signal intensity could be seen, which in contrast medium on T1 showed poor enhancement (
3). In another study, Lee et al. described a case of cervical cavernous hemangioma mimicking degenerated fibroma. In contrast to the study conducted by Kobayashi et al. (
3), there was no specific imaging characteristic for cavernous hemangioma due to multiple calcifications and massive hemorrhages within the mass. Non-enhanced CT only helped to detect the small size of calcifications. Hemorrhage could be seen as hyperintensity on T1 and hypointensity on T2 weighted images. Whereas, the heterogeneous high-signal intensities on T1 and T2 weighted images were interpreted as extensive necrosis. Sagittal T2 weighted images showed a beak-like mass arising from the anterior wall of the uterus (
10). Probable characteristic findings in these three cases were calcification, necrosis, and hemorrhage, which can be seen in degenerated myoma and leiomyosarcoma that put these two entities in the differential diagnosis of cavernous hemangioma.
Our case presented as diffuse enlargement of most of the myometrium that extended to the serosa and resulted in the lobulated border of uterine contour with high T2 signal and significant enhancement similar to the myometrium. Because of the pathology report of AIS in the resected cervical polyp, these MRI features were first misdiagnosed as cervical cancer with myometrial and para-uterine invasion. However, regarding normal hysteroscopic and physical exam, no hypoechoic space in the ultrasound exam (which is typical for hemangioma), and a normal cervical stroma and parametrium in MRI, the second radiologist’s opinion was a diffuse myometrial pathology as sarcoma. Although the features were not typical, based on only mild restriction of the lesion in DWI and the mentioned feature, low-grade sarcoma was proposed.
Leiomyosarcoma, as the most common uterine sarcoma, may present as a massive mass with rapid enlargement and an irregular border. The mass shows high to intermediate signal intensity on T2-weighted images, with hyperintense hemorrhagic changes on T1-weighted fat-suppressed images. On DWI, uterine leiomyosarcoma shows restricted diffusion (unlike our case) (
11). Nodular borders, hemorrhage, “T2 dark” areas, and central unenhanced areas are suggested as a differentiating feature of leiomyosarcoma from atypical leiomyomas (
12).
MRI features of degenerated leiomyoma depend on the degree of hyaline degeneration, myxoid portions, calcification, fatty, cystic, or hemorrhagic components of the tumor. Calcified or hyaline degeneration shows hypointensity on T1- and T2-weighted images. On the other hand, myxoid and cystic degeneration shows high signal intensity on T2-weighted images with minimal and no enhancement, respectively. Red degenerative leiomyomas have heterogeneous hyperintensity on T1- and T2- weighted images (
11).
In conclusion, we reported a case of uterine cavernous hemangioma with no typical imaging feature of this pathology that has ever been reported and was misdiagnosed as low-grade sarcoma. The present case highlights additional imaging features of this pathology that should be kept in mind as diffuse involvement of uterine myometrium with a lobulated border of uterine contour, an edematous signal in MRI, without endometrial involvement and mild restriction in DWI. Although the case did not have any hypoechoic areas in the ultrasound exam, multiple scattered linear low signal strands in the lesion in MRI could be a feature of diffuse cavernous hemangioma. More numbers of cases are needed to evaluate the specificity of this finding in future research.