Microsatellite instability in young patients with mucinous colorectal cancers – characterization using molecular testing, immunohistochemistry, and histological features

CONTEXT: The incidence of colorectal cancers (CRCs) in young Indian patients is higher than the international average. CRCs in young patients are commonly of mucinous type and show microsatellite instability (MSI). AIMS: To ascertain the MSI status of mucinous CRCs in patients ≤40 years of age by molecular testing and to correlate this with immunohistochemical (IHC) analysis and tumor histology. SUBJECTS AND METHODS: Archived formalin-fixed paraffin embedded tissue blocks of 30 young mucinous CRC patients were retrieved. MSI testing was done using two mononucleotide markers – BAT26 and NR24. IHC analysis was done using MLH1, MSH2, and MSH6. Histological features of all cases were studied. Data were analyzed using the SPSS software and the Pearson's chi-square test and Fisher's exact test. RESULTS: Eight out of 30 cases (26.7%) showed MSI by molecular testing. IHC identified seven of these cases. Histological features showing a statistically significant association with MSI were the presence of a well-differentiated adenocarcinoma component (P = 0.003), peritumoral lymphocytes (P = 0.002) and tumor budding (P = 0.021). CONCLUSION: The detection of defective mismatch repair (MMR) proteins using IHC for MLH1, MSH2, and MSH6 and molecular testing using BAT26 and NR24 appears to be a good protocol to detect CRCs with MSI. Histology could be useful in identifying cases that require screening for presence of MMR protein defects

Surgical manifestations of scrub typhus: A diagnostic dilemma.

Scrub typhus, a zoonosis caused by Orientia tsutsugamushi, is a systemic febrile illness. The disease presents with diverse clinical manifestations, ranging from subclinical disease to multiorgan failure and fatal disease. It may rarely present as an acute abdomen which may lead to a diagnostic dilemma. We describe two serologically confirmed cases of scrub typhus presenting as acute abdomen—one mimicking acute appendicitis and the other acute cholecystitis, both managed non-operatively. A high index of suspicion, along with subtle indicators in the history and clinical examination help avoid unnecessary surgery in such cases.

Anal sphincter repair for fecal incontinence: experience from a tertiary care centre .

Aim Structural anal sphincter damage may be secondary to obstetric anal sphincter injury, perineal trauma or anorectal surgery. We reviewed the spectrum of anal sphincter injuries and their outcomes in a tertiary care colorectal unit. Methods Data of patients who underwent anal sphincter repair between 2004 and 2008 were analyzed retrospectively. Outcomes were compared with respect to etiology, type of repair, previous attempts at repair and manometry findings. Outcomes were defined as good or poor based on patient satisfaction as the primary criteria. Results Thirty-four patients underwent anal sphincter repair. Twenty-two injuries were obstetric, eight traumatic, and four iatrogenic. All patients underwent overlap sphincteroplasty with six additional anterior levatorplasty and seven graciloplasty. Twenty-three (67.6%) patients had a good outcome while nine (26.4%) had a poor outcome. All patients who had augmentation anterior levatorplasty had a good outcome. Fifty percent of patients with a previous sphincter repair and 42.9% requiring augmentation graciloplasty had a poor outcome. Median resting and squeeze anal pressures increased from 57.5 to 70 cmH2O and 90.25 to 111 cmH2O in those with a good outcome. Conclusions Overlap sphincteroplasty has a good outcome in majority of the patients with incontinence due to a structural sphincter defect. Additional anterior levatorplasty may improve outcomes. Previous failed repairs or use of a gracilis muscle augmentation may have a worse outcome secondary to poor native sphincter muscle. Improvement in resting and squeeze pressures on anal manometry may be associated with a good outcome.

Selective histopathology in cholecystectomy for gallstone disease.

Background Incidental gallbladder cancer is found in upto 1% of cholecystectomy specimens for gallstone disease. Currently, in our institution, all gallbladder specimens are sent for routine histopathology, to rule out incidental gallbladder carcinoma. This study was aimed at assessing the need for routine histopathology of gallbladder specimens after cholecystectomy for gallstone disease. Methods Hospital records of all patients undergoing cholecystectomy for gallstone disease over a ten-year period, between 1998 and 2007, in a single surgical unit were reviewed. Results A total of 1312 patients underwent cholecystectomy for gallstone disease. Gallbladder carcinoma was detected in 13 patients. Macroscopic abnormalities of the gallbladder were found in all the 13 patients. In patients with a macroscopically normal gallbladder, there were no cases of gallbladder carcinoma. Conclusion Gallbladder carcinoma is associated with macroscopic abnormalities in all cases. Therefore histopathology should be restricted to only those specimens which reveal a macroscopic abnormality. This would identify all cases of incidental gallbladder carcinoma, at the same time decreasing cost and pathological work load.