IMAGES FOR SURGEONS

A 22-year-old male presented to a rural emergency department with a peritonitic abdomen on a background of a 2 week history of left upper quadrant pain. It was associated with decreased appetite, weight loss of 6 kg, abdominal distension and a visible mass in the left upper quadrant. He had no past medical, surgical or family history. Computed tomography of the abdomen revealed: a colonic lesion involving the distal transverse colon with thickening and invasion into the adjacent loops of small bowel, as well as ascites (Fig. 1). Urgent colonoscopy was arranged, however, the scope was unable to be passed beyond the near completely obstructing lesion. Biopsies were unable to be taken. The patient proceeded for an emergency laparotomy. Intraoperatively, a large distal transverse colon lesion was found with involvement of 20 cm of mid-to-upper loop of jejunum (Fig. 2). Widespread peritoneal deposits were noted. A right extended hemicolectomy, en-bloc resection of the adherent jejunal loops and biopsies of the peritoneal deposits was performed. The histopathology revealed a signet ring cell carcinoma (SRCC) of the transverse colon with serosal perforation and infiltration into mesentery of jejunum and greater omentum (Fig. 3). The peritoneal deposits were consistent with metastatic disease and the final pathological grade was T4b pN2b pN1 M1b. Computed tomography staging of the abdomen and pelvis showed extensive peritoneal deposits and regional lymph node metastases without chest or liver disease. The patient was referred on to the medical oncology service and was offered palliative chemotherapy because of advanced, incurable disease. The patient was started on CAPIRI (capecitabine/irinotecan) and bevacizumab; however, this was poorly tolerated and complicated by small bowel pseudo-obstruction. He was switched to FOLFIRI and bevacizumab. Unfortunately, he continued to have poor tolerance to the chemotherapy, and progress imaging showed progression of disease; the patient passed away shortly thereafter. Primary SRCC is a rare and poorly understood subtype of colorectal adenocarcinoma (CRC) that accounts for less than 1% of all colon cancers. Its absolute incidence in other organs is reported up to 92% within the glandular cells of stomach; however, also reported in the breast, gallbladder and pancreas. CRC is histologically differentiated into adenocarcinoma (majority), mucinous, SRCC and few even rarer subtypes. A greater proportion of those diagnosed with SRCC are under the age of 40 (3 versus 0.87% relative to other CRC), with increased findings of nodal and metastatic spread. There have been 14 case reports published for patients under the age of 40 and limited to the colon since 1999. Epidemiological data demonstrate associations towards the Asian population with no relevant historical risk factors. Initial presenting problems are often undifferentiated vague abdominal pain, change in bowel habits, weight loss and loss appetite. Some patients present with an acute abdomen, without preceding symptoms. Surgical treatment options are not dissimilar to those offered for other CRCs. Resection of the tumour is preferred. However, there is increasing evidence to suggest patients may be receiving high rates of unsuccessful operations due to diagnostic delay and subsequent advanced disease stage. Compared with mucinous and adenocarcinoma CRCs, SRCC histology has a poor prognosis, due to delayed diagnosis and poor overall survival. At time of diagnosis, TNM III and IV staging was found in 90% of SRCC versus only 48% in other subtypes, with higher incidence of lymphatic spread to contiguous or