case_images: PMC6029189_01
case_images: A 56-year-old man with a mucinous adenocarcinoma in the appendix (Case 2).(a) A coronal computed tomography scan of the appendix shows cystic dilatation of the appendix (arrow, A) and irregular wall thickening. (b) Axial sonography of the appendix also shows cystic dilatation of the appendix and irregular wall thickening (arrow, B). (c) A low-power microphotograph shows a cystic, dilated appendix with abundant intraluminal mucin (H and E, x10). (d) The appendiceal lumen is lined by a mixture of high-grade, pseudostratified, columnar, neoplastic epithelium and low-grade, mucinous epithelium (H and E, x40)
case_images: JMU-26-52-g001.jpg
case_images: PMC6029189_01_JMU-26-52-g001.jpg
case_images: F1
case_images: Two mucinous cystadenocarcinomas had markedly enlarged inner luminal diameters (mean, 23 mm; range, 15-31 mm) and irregular, thick walls (5.5 mm; 5-6 mm) [Figure 1].
case_images: A 79-year-old man with a nonmucinous adenocarcinoma in the appendix (Case 4). (a) An axial sonography shows an irregular, hypoechoic mass (arrow) at the appendiceal base and cecum. Loss of the wall layer pattern is also noted. (b) On gross examination, adenocarcinoma (arrow) was detected at the appendiceal base. (c) A low-power microphotograph showes tumor cells infiltrating the mucosa, submucosa, muscularis, and serosa layers and periappendiceal tissue (H and E stain, x100). B, appendix base; C, cecum; L, lumen; M, muscle; m, mucosa; S, serosa; sm, submucosa; P, periappendiceal tissue
case_images: JMU-26-52-g002.jpg
case_images: PMC6029189_01_JMU-26-52-g002.jpg
case_images: F2
case_images: On the other hand, five nonmucinous carcinomas (4 adenocarcinomas and a signet-ring cell carcinoma) had relatively small inner luminal diameters (6.6 mm +- 4.5 mm, 2-15 mm) and prominent thick walls (6.2 mm +- 2.3 mm, 3-10 mm) [Figure 2].