A Rare Presentation of Recurrent Malignant Peripheral Nerve Sheath Tumor with Glandular Differentiation-A Case Report.

Malignant peripheral nerve sheath tumors (MPNST) are rare heterogeneous group of soft tissue neoplasms. In most cases, they originate within the pre-existing neurofibromatosis. The emergence of glandular structures in MPNST is curious and enigmatic. We report a case of recurrent MPNST with glandular differentiation arising in the background of neurofibroma in a 20-year-old lady. By immunohistochemistry, MPNST showed focal positive staining for S100 and negative staining for SOX10 while adjacent neurofibroma showed diffuse positivity for S100 and SOX10. The glandular tumor cells showed positive staining for CDX2, Cam5.2, CK19, and CK7 (focal), while negative for SOX10 and S100. MPNST with glandular differentiation is quite rare which may pose a diagnostic challenge. The glandular differentiation in MPNST should be excluded from the metastasis from second primary with the aid of clinical and radiological correlation.

Early Onset Colorectal Cancer in Arabs, Are We Dealing with a Distinct Disease?

Early-onset colorectal cancer (EOCRC) incidence is increasing worldwide. Efforts are directed to understand the biological and clinical signatures of EOCRC compared to late-onset colorectal cancer (LOCRC). EOCRC is thought to present differently across different ethnic groups and geographical regions. This study was an attempt to contribute with data from the Arab world toward the understanding of the clinicopathological parameters of EOCRC compared to LOCRC. Data from 254 CRC patients diagnosed at Sultan Qaboos University Hospital from the period 2015-2020 were studied. About 32.6% of all diagnosed CRC patients are below 50 years old, with no differences in gender distribution between EOCRC and LOCRC (p-value 0.417). Rectal involvement and tumor laterality were comparable among the two groups. Adenocarcinoma accounts for 83.3% and 94.2% of EOCRC and LOCRC, respectively. More mucinous and signet ring adenocarcinoma (8.3% each) were reported in EOCRC than LOCRC (2.9% and 2.2%, respectively). MLH1 and PMS2 loss are more common among LOCRC, but MSH6 loss is more frequent in EOCRC. The overall survival of EOCRC and LOCRC was comparable (median survival 64.88 and 67.24 months, respectively). This study showed comparable clinicopathological parameters between EOCRC and LOCRC from Arabs, which adds to the bigger picture of understand the disease.

Basidiobolus omanensis sp. nov. Causing Angioinvasive Abdominal Basidiobolomycosis.

Human infectious fungal diseases are increasing, despite improved hygienic conditions. We present a case of gastrointestinal basidiobolomycosis (GIB) in a 20-year-old male with a history of progressively worsening abdominal pain. The causative agent was identified as a novel Basidiobolus species. Validation of its novelty was established by analysis of the partial ribosomal operon of two isolates from different organs. Phylogeny of ITS and LSU rRNA showed that these isolates belonged to the genus Basidiobolus, positioned closely to B. heterosporus and B. minor. Morphological and physiological data supported the identity of the species, which was named Basidiobolus omanensis, with CBS 146281 as the holotype. The strains showed high minimum inhibitory concentrations (MICs) to fluconazole (>64 µg/mL), itraconazole and voriconazole (>16 µg/mL), anidulafungin and micafungin (>16 µg/mL), but had a low MIC to amphotericin B (1 µg/mL). The pathogenic role of B. omanensis in gastrointestinal disease is discussed. We highlight the crucial role of molecular identification of these rarely encountered opportunistic fungi.

Encapsulating Peritoneal Sclerosis: A Case Report and Literature Review.

BACKGROUND Encapsulating peritoneal sclerosis (EPS) is a rare, life-threatening, and serious complication of long-term peritoneal dialysis (PD). No evidence-based management strategy has been established until now. Surgical management, including enterolysis and excision of the sclerotic and obstructing adhesions, should be considered as soon as conservative management fails to work. We report a case of EPS soon after transplantation in a patient with end-stage kidney disease who had been on long-term PD. CASE REPORT A 26-year-old man had been found to have advanced chronic kidney disease secondary to glomerulonephritis on pre-employment investigation. He was on continuous ambulatory PD for 5 years, after which he underwent a living donor renal transplant from his full HLA-matched sibling. He did well postoperatively, with excellent graft function. One month after transplantation, he repeatedly presented to our Emergency Department with signs and symptoms of complete small-bowel obstruction. Computed tomography of the abdomen showed features of small-bowel obstruction secondary to interloop adhesions. The patient was initially managed conservatively; however, as his condition continued to deteriorate, an exploratory laparotomy was carried out. Operative findings were suggestive of early EPS localized to the terminal ileum. Total enterolysis along with peritonectomy was performed along with resection of the diseased and obstructing terminal ileum. The patient did well, and he was discharged home day 10 postoperatively. CONCLUSIONS EPS remains a serious and fatal complication of long-term PD. Early definitive diagnosis, treatment, and ultimately surgical intervention may be required to prevent the morbidity and mortality associated with this condition.

Caecal duplication cyst leading to intussusception in an adult.

Colonic duplication cyst is an uncommon cause of intussusception in adults. We report a case of caecal duplication cyst in a 24-year-old adult with a 3-year history of recurrent abdominal pain mainly in the periumbilical region. CT and MRI of the abdomen showed a lesion suggesting an caecal duplication cyst within an intussuception. The patient underwent diagnostic laparoscopy and was found to have a caecal duplication cyst acting as a lead point for the intusseception for which laparoscopic-assisted resection was performed. The histological examination confirmed the presence of intestinal duplication cyst without any underlying malignancy.

Primary Gastric Yolk Sac Tumour.

Primary gastric yolk tumours are extremely rare. We report a 52-year-old male who presented to the Sultan Qaboos University Hospital, Muscat, Oman, in 2017 after having undergone a gastrectomy abroad due to a suspected poorly-differentiated adenocarcinoma. The patient subsequently returned to Oman to receive chemotherapy. However, while undergoing chemotherapy, an abdominal computed tomography scan revealed a lobulated mesenteric mass. Microscopic examination of the resected lesion confirmed a diagnosis of a yolk sac tumour. The mass was diffusely positive for α-fetoprotein (AFP) and a gastric carcinoma stain was negative. Gastrectomy slides from the patient's previous surgery were examined retrospectively. The morphology was typical for a yolk sac tumour and was negative for epithelial markers. An AFP stain showed diffuse immunoreactivity. Thus, the patient was deemed to have had a primary gastric yolk sac tumour which had later metastasised to the mesocolon. Germ cell tumour protocols were initiated and the patient responded well to treatment.

Clostridium difficile colitis: increasing incidence, risk factors, and outcomes in solid organ transplant recipients.

BACKGROUND: Clostridium difficile-associated diarrhea (CDAD) is an increasingly important diagnosis in solid organ transplant recipients, with rising incidence and mortality. We describe the incidence, risk factors, and outcomes of colectomy for CDAD after solid organ transplantation. METHODS: Patients with CDAD were identified from a prospective transplant database. Complicated Clostridium difficile colitis (CCDC) was defined as CDAD associated with graft loss, total colectomy, or death. RESULTS: From 1999 to 2010, we performed solid organ transplants for 1331 recipients at our institution. The incidence of CDAD was 12.4% (165 patients); it increased from 4.5% (1999) to 21.1% (2005) and finally 9.5% (2010). The peak frequency of CDAD was between 6 and 10 days posttransplantation. Age more than 55 years (hazard ratio [HR]: 1.47, 95% confidence interval [CI]=1.16-1.81), induction with antithymocyte globulin (HR: 1.43, 95% CI=1.075-1.94), and transplant other than kidney alone (liver, heart, pancreas, or combined kidney organ) (HR: 1.41, 95% CI=1.05-1.92) were significant independent risk factors for CDAD. CCDC occurred in 15.8% of CDAD cases. Independent predictors of CCDC were white blood cell count more than 25,000/µL (HR: 1.08, 95% CI=1.025-1.15) and evidence of pancolitis on computed tomography scan (HR: 2.52, 95% CI=1.195-5.35). Six patients with CCDC underwent colectomy with 83% patient survival and 20% graft loss. Of the medically treated patients with CCDC (n=20), the patient survival was 35% with 100% graft loss. CONCLUSIONS: We have identified significant risk factors for CDAD and predictors of progression to CCDC. Furthermore, we found that colectomy can be performed with excellent survival in selected patients.