Prognosis of Signet Ring Cell Carcinoma of the Colon and Rectum and their Distinction of Mucinous Adenocarcinoma with Signet Ring Cells. A Comparative Study

Abstract

Signet ring cell carcinoma (SRCC) of the colorectum is very rare, comprising between <1% and 2.4% cases of colorectal cancer. Patients' prognoses are poor. Several case reports had described as SRCC cases that are mucinous adenocarcinomas (MAC) with signet ring cells (SRC). In order to clearly delineate between MAC with SRC and SRCC, we performed a retrospective study at a national cancer referral center in which survival and clinicopathological characteristics between these two forms were compared and also SRCC were characterized by immunohistochemistry. We retrieved 32 cases that had been classified as either SRCC or MAC with SRC subtypes. It was noted that SRCC patients presented at older ages, demonstrated more advanced clinical stages, lymphovascular invasion, lymph node metastases, and higher carcinoembrionic levels than MAC with SRC patients. Regarding SRCC immunophenotype, 50% showed loss of CDX2 expression, 33% were CK20 negative, 41.7% were CK7 positive, and 25% were negative for both CK7 and CK20. For the MAC with SRC and SRCC groups, the median disease-specific survival (DSS) was 46.1 months (95% CI 36.9-55.25) and 22.4 months (95% CI 5.1-39.7 [p = 0.039]), respectively. The 3-year DSS was 80.7% and 28.6% (p = 0.017) for the MAC and SRCC patients, respectively. Univariate and multivariate analyses showed that SRCC was associated with decreased survival. SRCC had several clinicopathological features that permitted differentiation of MAC with SRC from SRCC patients, who had a poor DSS. A differential diagnosis for metastatic gastric cancer is only possible with a good clinicopathological correlation.

Adenosquamous carcinoma of the right colon with diffuse signet-ring mucinous component

“…In our knowledge, this is the first case reported in literature in which a diffuse signet-ring cells component is detected. The latter, although present in a small amount, has been reported to worsen the prognosis [11]. The role of microsatellite instability (MSI) in the pathogenesis of ASC is still unclear.…”

A Rare Case of Signet Cell Carcinoma of Transverse Colon in a Young Patient With Ulcerative Colitis

“…The name SRCC is a descriptive term describing a carcinoma cell retaining abundant intracytoplasmic mucin that causes the nucleus to be pushed to the periphery of the cell. In affected sites, the tumor infiltrates the entire wall, therefore results in a rigid and contracted structure called the linitis plastica [ 5 ]. The majority of these tumors arise in the stomach.…”

“…WHO definition of SRCC is carcinoma confirmed by > 50% of SRCC but states that SRCC can occur within the pools of MAC or in a diffusely infiltrative process with minimal extracellular mucin in a linitis plastica pattern [ 9 ]. Luis et al described in his retrospective study that 68.7% of SRCC cases occur in the right colon, 9.4% in the transverse and 21.9% in the left colon [ 5 ]. Our patient had the tumor on the transverse colon.…”

“…On the other hand, the World Health Organization (WHO) defined MAC as a carcinoma confirmed by > 50% of extracellular mucin pools that contain malignant epithelial or individual tumor cells including SRCC [ 4 ]. SRCC mainly occurs on the right side of the colon [ 5 ]. The main differential diagnosis is metastatic gastric carcinoma with SRCC, and it is necessary to rule out this diagnosis by endoscopy before finalizing a diagnosis of primary colorectal SRCC.…”

Signet ring cell carcinoma of the rectum: atypical metastatic presentation

“…The metastatic sequence of signet cell rectal carcinoma seems to be entirely different and is nonpredictable. This phenomenon appears to be secondary to the presence of anaplastic and undifferentiated cells with the capacity to cause diffuse infiltration followed by rapid dissemination from all the structures adjacent to the tumours primary site 11…”