Zhu Qing-Qing, Niu Zhong-Feng, Yu Fei-Dan, Wu Yan, Wang Guang-Bin
Department of Radiology, Shandong Medical Imaging Research Institute, Cheeloo College of Medicine, Shandong University, Jinan 250021, Shandong Province, China.
Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310000, Zhejiang Province, China.
World J Clin Cases. 2021 Mar 16;9(8):1931-1939. doi: 10.12998/wjcc.v9.i8.1931.
Angiomyolipomas (AMLs), belonging to the family of mesenchymal tumors, are considered benign lesions that occur mostly in the kidney or as a part of tuberous sclerosis. Epithelioid AML (EAML) is a rare type of AML that appears to have malignant potential. Extrarenal AMLs usually occur in the liver according to the retrieved literature reports. There have been only two previous reports of monofocal primary AML of the pancreas; however, no cases of primary monotypic EAML of the pancreas have been reported.
An asymptomatic 59-year-old woman incidentally revealed a tumor during abdominal ultrasound examination. Routine blood tests and physical examination were within normal limits. Abdominal ultrasound revealed a 1.9-cm hypoechogenic mass in the tail of the pancreas, clearly visualized by endoscopic ultrasound. However, contrast-enhanced abdominal computed tomography scans did not demonstrate the lesion. A subsequent gadolinium-enhanced magnetic resonance imaging scan showed that the lesion had some characteristic manifestations. The lesion was initially thought to be a neuroendocrine tumor (asymptomatic PanNET). After surgical resection, histopathology and immunohistochemistry confirmed the diagnosis of EAML. At the 6-mo follow-up, no recurrence, spread, or metastasis was identified on computed tomography or magnetic resonance imaging.
The preoperative diagnosis of pancreatic AML is extremely difficult. Imaging techniques are essential for providing valuable morphological features for differential diagnosis.
血管平滑肌脂肪瘤（AML）属于间叶性肿瘤家族，被认为是良性病变，主要发生于肾脏或作为结节性硬化症的一部分。上皮样AML（EAML）是AML的一种罕见类型，似乎具有恶性潜能。根据检索到的文献报道，肾外AML通常发生于肝脏。此前仅有两篇关于胰腺单灶性原发性AML的报道；然而，尚无胰腺原发性单型EAML的病例报道。
一名59岁无症状女性在腹部超声检查时偶然发现一个肿瘤。常规血液检查和体格检查均在正常范围内。腹部超声显示胰腺尾部有一个1.9厘米的低回声肿块，内镜超声可清晰显示。然而，腹部增强计算机断层扫描未显示该病变。随后的钆增强磁共振成像扫描显示该病变有一些特征性表现。该病变最初被认为是神经内分泌肿瘤（无症状胰腺神经内分泌肿瘤）。手术切除后，组织病理学和免疫组化确诊为EAML。在6个月的随访中，计算机断层扫描或磁共振成像未发现复发、扩散或转移。
胰腺AML的术前诊断极其困难。影像学技术对于提供有价值的形态学特征以进行鉴别诊断至关重要。
