阑尾黏液囊肿1例MR影像表现

History: A 30-year-old pregnant woman presents to her primary care physician with abdominal pain. She underwent a pelvic ultrasound scan, which revealed a complex right adnexal structure, and an MRI scan was recommended.

病史:30岁孕妇,腹部疼痛就诊。行盆腔超声扫描发现复杂的右附件结构,进一步行MRI扫描。

Images are shown below. In order: sagittal ultrasound image of the right flank, coronal T2-weighted half-Fourier acquisition single-shot turbo spin-echo (HASTE) images, axial T2-weighted HASTE image, and an axial T1-weighted volumetric interpolated breath-hold examination (VIBE) fat-saturated image.

图像如下所示,分别为:右下腹矢状超声图像,冠状/轴位T2WI HASTE,轴位T1WI VIBE脂肪抑制。

【病例】阑尾黏液囊肿1例MR影像表现

【病例】阑尾黏液囊肿1例MR影像表现

【病例】阑尾黏液囊肿1例MR影像表现

【病例】阑尾黏液囊肿1例MR影像表现

【病例】阑尾黏液囊肿1例MR影像表现

【病例】阑尾黏液囊肿1例MR影像表现

【病例】阑尾黏液囊肿1例MR影像表现

Findings

Abdominal MRI demonstrates a tubular cystic structure adjacent to the cecum in the right lower quadrant of the abdomen measuring 24 x 30 x 95 mm. No wall thickening or nodularity is visualized. No surrounding edema or fluid is noted.

影像表现:

腹部MRI示右下腹一管状囊性结构,大小约24 x 30 x 95 mm,邻近盲肠,囊壁无明显增厚,未见壁结节,无周围水肿或积液。

Differential diagnosis

  • Appendiceal mucocele
  • Acute appendicitis (abscess)
  • Appendiceal tumors
  • Cecal carcinoma
  • Ovarian cystic mass
  • Cystic fibrosis

鉴别诊断:

  • 阑尾黏液囊肿
  • 急性阑尾炎(脓肿)
  • 阑尾肿瘤
  • 盲肠癌
  • 卵巢囊性肿物
  • 囊性纤维化

Diagnosis: Appendiceal mucocele

最后诊断:阑尾黏液囊肿

WHAT IS THE UPPER LIMITS OF NORMAL FOR APPENDICEAL DIAMETER?

6 mm (the correct answer)

阑尾直径的正常上限为:6mm。

Discussion

Appendiceal mucocele

阑尾黏液囊肿

Pathophysiology

Appendiceal mucoceles are caused by abnormal accumulation of mucin in the appendix, resulting in dilatation. They can be caused by benign processes such as luminal obstruction, mucosal hyperplasia, appendiceal carcinoid, or mucin-secreting epithelial tumors.

病理生理学

阑尾粘液肿是由粘液在阑尾内异常积聚引起的,导致扩张。可能由良性过程引起,如腔内阻塞,粘膜增生,阑尾类癌或粘液分泌型上皮肿瘤。

Epidemiology

At appendectomy, the reported prevalence of appendiceal mucoceles is 0.2% to 0.3%. They tend to be present in middle-aged adults. They can be associated with colonic adenocarcinoma or cystic fibrosis.

流行病学

在阑尾切除术中,阑尾粘液脓肿的发生率为0.2%至0.3%,多发生于中年人,可能与结肠腺癌或囊性纤维化有关。

Clinical presentation

Most patients are asymptomatic. Occasionally, patients will present with tender right lower quadrant pain or a palpable mass. If appendiceal mucoceles rupture and the underlying cause is neoplastic, patients can end up with pseudomyxoma peritonei. The appendiceal mucocele can also be the lead point for an ileocolic intussusception.

临床表现

大多数患者无症状。偶尔会出现右下腹痛或触及肿块。如果阑尾黏液囊肿破裂并且其根本原因是肿瘤,则患者可能最终表现为腹膜假性黏液瘤。阑尾粘液囊肿也可导致回肠-结肠套叠

【病例】阑尾黏液囊肿1例MR影像表现

Imaging features

  • Barium enema: If a barium enema is performed in the setting of an appendiceal mucocele there can be nonfilling or partial filling of the appendix.
  • Ultrasound: Appendiceal mucoceles are typically cystic masses with variable internal echogenicity. An onion sign, or sonographic layering within a cystic mass, is a highly sensitive feature.
  • CT: Simple mucoceles appear as well-defined, low-density cystic masses in the right lower quadrant. There can be curvilinear calcifications within the wall. Mucinous cystadenomas are indistinguishable from simple mucoceles by CT.
  • MRI: Appendiceal mucoceles are oval or spherical pericecal masses that are hypointense on T1-weighted imaging and bright on T2-weighted imaging.

影像表现:

  • 钡灌肠:如果在有阑尾黏液囊肿的情况下进行钡剂灌肠,则可能会出现阑尾未充盈或部分充盈。
  • 超声:阑尾黏液囊肿通常是具有可变内部回声的囊性肿块。洋葱征或囊性肿块内的声像图分层是一种高度敏感的特征。
  • CT:单纯黏液囊肿在右下腹表现为界限清楚的低密度的囊性肿块囊壁可见曲线样钙化。CT上粘液性囊腺瘤与单侧黏液囊肿不易区分。
  • MRI:阑尾黏液囊肿为椭圆形或球形的盲肠周围肿物,在T1WI上呈低信号,在T2WI上呈明亮高信号。

Treatment

The treatment of appendiceal mucoceles is surgical resection, usually a right hemicolectomy.

治疗:阑尾黏液囊肿的治疗方法是手术切除,通常行右半结肠切除术。

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