Sonographic findings of malignant appendix tumors in seven cases

Abstract

We report the sonographic features of confirmed malignant appendiceal tumors in seven cases. The histologic diagnoses of these tumors were mucinous cystadenocarcinoma (n = 2), colonic type adenocarcinoma (n = 4), and signet-ring cell carcinoma (n = 1). The 2 mucinous cystadenocarcinomas showed mucocele type, which had markedly enlarged inner luminal diameters (mean, 23 mm; range, 15–31 mm) and thick, irregular walls (mean wall thickness, 5.5 mm; range, 5–6 mm). In contrast, the 5 nonmucinous carcinomas (4 adenocarcinomas and 1 signet-ring cell carcinoma) showed nonmucocele type, which had relatively small inner luminal diameters (mean ± standard deviation [SD], 6.6 ± 4.5 mm; range, 2–15 mm) and prominent wall thickening (mean wall thickness ± SD, 6.2 ± 2.3 mm; range, 3–10 mm). Of the 5 nonmucinous tumors, only one had a discernible mass, three had thick irregular walls, two had loss of the wall layer pattern, and four had submucosal hypoechogenicity. Regardless of the histologic type, five of the seven malignant appendiceal tumors showed a severe periappendiceal fat infiltration or periappendiceal abscess, suggestive of perforation. Although the sonographic findings of the malignant appendiceal tumors were nonspecific, some of the sonographic features seen in these seven cases may help radiologists consider the possibility of underlying malignant appendiceal tumors.

Clinical benefits of FOLFOXIRI combined with bevacizumab for advanced-stage primary signet ring cell carcinoma of the appendix: A case report

“…[21] A previous research confirmed that colon cancer presents the following features in high-resolution ultrasound: heterogeneous hypoechoic masses, irregular wall thickening, and absence of lamellar walls. [21] Cho et al described the distinction between neoplastic and non-neoplastic inflammatory responses of the appendix. Firstly, the true lumen diameter of neoplastic inflammation of the appendix is typically smaller than that of acute appendicitis.…”

“…The ultrasonographic manifestations of non-mucinous carcinoma of the appendix (including adenocarcinoma and SRCC) are relatively small intestinal lumen diameter, appendix wall thickening or submucosal hypoecho. [21] A previous research confirmed that colon cancer presents the following features in high-resolution ultrasound: heterogeneous hypoechoic masses, irregular wall thickening, and absence of lamellar walls. [21] Cho et al described the distinction between neoplastic and non-neoplastic inflammatory responses of the appendix.…”

“…[24] Studies have shown that CDX2 and SATB2 were positively expressed in all the lower gastrointestinal primary tumors and negatively expressed in the majority of upper gastrointestinal primary tumors. [21] In addition, mucins (MUC-1, MUC-2) are helpful for the differentiation of metastatic appendix originated from the ovary. Yajima et al reported that all malignant tumors of the appendix were expressed with MUC-2, whereas ovarian cancer only expressed with MUC-1, rather than with MUC-2.…”

Retrospective analysis of the incidence of appendiceal neoplasm and malignancy in patients treated for suspected acute appendicitis

“…Radiological features for appendiceal tumours in ultrasound and computed tomography (CT) are nonspecific and occult [ 26 , 27 ]. But depending on the entity of appendiceal malignancies some sonographic features such as enlarged or small inner luminal diameter, thick and irregular appendix wall, loss of layer pattern of the appendix wall, and even hypoechogenicity are described [ 26 ]. In addition, infiltration of the periappendiceal fat or even abscess formation with suspicion of appendix perforation may be seen in cases of appendiceal malignancies [ 26 ].…”

“…But depending on the entity of appendiceal malignancies some sonographic features such as enlarged or small inner luminal diameter, thick and irregular appendix wall, loss of layer pattern of the appendix wall, and even hypoechogenicity are described [ 26 ]. In addition, infiltration of the periappendiceal fat or even abscess formation with suspicion of appendix perforation may be seen in cases of appendiceal malignancies [ 26 ]. Findings in abdominal CT scans are again depending on the underlying type of malignancy and reach from hyperenhancement, nodular wall thickening, calcification, mucocele, lymphadenopathy, periappendiceal fat infiltration, or tumour mass [ 27 ].…”