Department of Radiology, Etimesgut Sehit Sait Ertürk State Hospital, Ankara, Turkey.
Department of Radiology, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey.
Curr Med Imaging. 2022;18(1):86-90. doi: 10.2174/1573405617666210712122127.
Lipomas are benign fatty tumors made of fat tissue. Bladder lipomas are extremely rare. For this reason, it is necessary to be aware of the imaging features when incidentally detected in imaging.
In the abdominal Computed Tomography (CT) performed as part of the follow-up examination of a 43-year-old patient, who had undergone surgery for adrenal adenoma five years earlier, a 14x9x8 mm smoothly marginated, ovoid-shaped, hypodense mass lesion with a homogeneous internal structure was detected in the anterior bladder wall. The pre-contrast density of the lesion was measured as -105 HU. The magnetic resonance imaging performed one year after the CT examination revealed a 14x9x8 intramural mass in the bladder wall, showing protrusion toward the lumen. The mass was observed to be markedly hypointense on fat-suppressed T1 and T2-weighted images and considered to be consistent with a bladder lipoma.
Bladder lipomas are benign lesions that can vary in clinical presentations but usually cause hematuria. In imaging, bladder lipomas are present as homogeneous lesions containing macroscopic fat. The differential diagnosis of bladder lipomas includes other mesenchymal rare benign tumors that can arise from the submucosal layer of the urinary bladder including leiomyoma, hemangioma, plasmacytoma, fibroma, and neurofibroma. Only the liposarcoma and pelvic lipomatosis could show similar features. The less differentiated liposarcomas tend to present more heterogeneous enhancement, irregular-shaped margins, and infiltrative behaviour. Also, appropriate multiplanar reconstructions may allow the radiologist to determine if it is an extravesical pelvic lipomatosis.
Using CT and MRI, the lesions that are rich in adipose tissue can be distinguished from other lesions, and their diagnosis can be made to a great extent. However, a histopathological examination is required for a definitive diagnosis.
脂肪瘤是由脂肪组织构成的良性脂肪肿瘤。膀胱脂肪瘤极为罕见。因此，当在影像学检查中偶然发现时，有必要了解其影像学特征。
在对一名 43 岁患者进行的腹部计算机断层扫描（CT）检查中，该患者五年前因肾上腺腺瘤接受了手术治疗，在前膀胱壁处检测到一个 14x9x8mm 边界光滑、卵圆形、低密病灶，内部结构均匀。病灶的平扫密度为-105HU。在 CT 检查一年后进行的磁共振成像（MRI）显示，膀胱壁内有一个 14x9x8mm 的壁内肿块，向管腔突出。该肿块在脂肪抑制 T1 和 T2 加权图像上表现为明显低信号，考虑为膀胱脂肪瘤。
膀胱脂肪瘤是良性病变，临床表现多样，但通常会引起血尿。在影像学检查中，膀胱脂肪瘤表现为含有大量脂肪的均匀病灶。膀胱脂肪瘤的鉴别诊断包括其他源自膀胱黏膜下层的罕见良性间叶肿瘤，包括平滑肌瘤、血管瘤、浆细胞瘤、纤维瘤和神经纤维瘤。只有脂肪肉瘤和骨盆脂肪增多症可能表现出类似特征。分化程度较低的脂肪肉瘤往往表现出更不均匀的强化、不规则形状的边缘和浸润性行为。此外，适当的多平面重建可以让放射科医生确定它是否是盆腔脂肪增多症。
使用 CT 和 MRI，可以区分富含脂肪组织的病变与其他病变，并在很大程度上做出诊断。但是，需要进行组织病理学检查以明确诊断。
