History: A 36-year-old woman presents with nauseaand constipation.
病史：36岁女性，恶心，便秘。
Axial unenhancedand contrast-enhanced arterial-, venous-, and delayed-phase images fromabdominal CT are shown below.
轴位CT平扫及增强扫描（动脉期、静脉期、延迟期），如下所示。
Findings
CT demonstrates a6-cm hypoattenuating lesion in the right hepatic dome with peripheral nodularenhancement on early phase images, followed by centripetalenhancement during the later phase.
表现：肝右顶部可见一6cm大小的低密度灶，增强扫描早期外周结节样强化，晚期呈渐进性向心性强化。
Differential diagnosis
- Cavernous hemangioma
- Focal nodular hyperplasia
- Hypervascular metastasis
- Hepatocellular carcinoma
- Hepatic adenoma
- Hepatic abscess
鉴别诊断：
- 海绵状血管瘤
- 局灶性结节性增生
- 富血供转移瘤
- 肝细胞癌
- 肝腺瘤
- 肝脓肿
Diagnosis：Cavernous hemangioma
诊断：海绵状血管瘤
Key points
Cavernous hemangioma
Clinical overview 临床概况
Cavernous hemangiomas are the most common benign hepatic masses.
海绵状血管瘤是最常见的良性肝脏肿物。
Hepatic hemangiomas are generally asymptomatic and incidentally discovered.
肝血管瘤通常无临床症状，偶然发现。
Hepatic hemangiomas are most commonly discovered in women ages 30 to 50.
肝血管瘤最常见于30-50岁女性。
Although typically associated with hepatic adenomas, exogenous estrogen and high-estrogen states (e.g., pregnancy) also have been associated with an increase in the size and number of hemangiomas. These lesions will often regress with reduction of circulating estrogen levels.
和肝腺瘤有一定关联，外源性雌激素高水平状态（例如：怀孕）可能会导致血管瘤体积增大，数量增加，随着雌激素水平的下降，病变也会有所消退。
When patients are symptomatic, right upper quadrant abdominal pain and fullness are the most common complaint.
患者一旦有症状，常表现为右上腹痛、饱胀。
Complications are generally seen in giant hemangiomas (larger than 5 cm) and occur more often than in their smaller counterparts.They include inflammatory changes, intralesional hemorrhage, intraperitoneal hemorrhage, and potential volvulus of a pedunculated lesion.
并发症常见于巨大海绵状血管瘤（大于5cm），包括：炎性改变，病灶内出血，腹腔内出血，带蒂病灶扭转。
CT findings CT表现
Cavernous hemangiomas appear as well-circumscribed, round or lobular, hypoattenuating lesions on unenhanced imaging.
海绵状血管瘤表现为边界清楚，类圆形或分叶状，平扫呈低密度。
With contrast, they generally demonstrate peripheral nodular/discontinuous enhancement and centripetal filling on delayed imaging.
增强扫描通常表现为外周结节样非连续性强化，延迟期渐进性向心性填充。
This appearance is secondary to contrast material entering the multiple vascular channels and slowly filling in the lesion.
这种表现继发于造影剂进入多发血管通路并缓慢充填病灶。
Areas with minimal to no enhancement may be secondary to extensive scar or to cystic cavities filled with serous fluid.
轻度至无强化区域可能继发于大量瘢痕或者充填浆液性液体的囊性空腔。
Central scarring is typically seen in hemangiomas larger than 3 cm and may be the result of ischemia or hemorrhage.
中心瘢痕，最常见于直径大于3cm的血管瘤，可能是缺血或出血的结果。
Giant hemangiomas may also show asymmetric enhancement due to regions of thrombosis.
巨大海绵状血管瘤由于局部血栓形成，可表现为非对称性强化。
Treatment 治疗
Hepatic hemangiomas are generally stable in size. Larger lesions (more than 5 cm) may be followed to exclude a rapid size increase.
肝血管瘤通常大小较稳定，直径大于5cm的病变需要随访除外肿瘤体积迅速增大。
Biopsy carries the risk of potentially fatal hemorrhage and has no role in diagnosis.
诊断不采用穿刺活检，因其有导致潜在致命出血的可能。
In the absence of symptoms, the risks outweigh the potential benefits for invasive management of hepatic hemangiomas. Even when symptomatic, up to 25% of patients will report persistent symptoms after surgical excision. Therefore, a search to exclude other etiologies to explain the patient’s symptoms is important prior to any intervention.
没有症状时，肝血管瘤介入治疗的风险要大于其带来的好处。即使有症状，多达25%的患者在手术切除后症状仍持续出现，因此，排除导致患者症状的其它原因比任何干预更重要。