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.

Evaluation of an enhanced pathological examination protocol for sentinel lymph nodes from patients with breast carcinoma.

Clinical trials have shown that many patients with breast cancer with limited sentinel lymph node (SLN) metastatic disease can safely avoid axillary lymph node dissection. Ultra-staging of initially negative SLNs may not confer additional clinical benefit. Despite this, protocols of 'enhanced pathological examination' (EPE) are still widely used. We evaluated the impact of our EPE protocol. If initial SLN H&Es are negative, we cut three additional H&E levels at 500 µm intervals with two spare sections at each level, to allow for immunohistochemistry if necessary. Occult micrometastases or isolated tumour cells were identified, using this protocol, in 3.4%, resulting in change of N stage in 3%. 1% of patients had further axillary surgery based on these findings. Our SLN-EPE protocol provided additional information in a small number of cases and changed axillary management in a minority. It represented a significant workload for scientists and pathologists, and had time and cost implications. We concluded that emphasising careful gross examination along with judicious use of additional levels and immunohistochemistry may be more beneficial than our current protocol.

Histomorphological Spectrum of Papillary Carcinoma of Thyroid in Oman.

Thyroid cancer is the commonest endocrine malignancy and is the second most common cancer affecting young females in Oman. The diagnosis of Papillary Thyroid Carcinoma (PTC) is based primarily on histologic architecture and nuclear morphology in routine Haematoxilin and Eosin (H & E) stained slides. Whenever in doubt, immunohistochemistry may be helpful. This retrospective study included 115 cases of PTC diagnosed at a tertiary care center in Oman over 10 years period, from 2001 to 2010. Slides and blocks of these cases were retrieved from the pathology laboratory. Ninety five (95) were females and 20 were males. Papillary Thyroid Carcinoma (PTC) was most commonly seen in the 20 - 50 years of age. The commonest morphologic variant seen in this population was classical papillary variant in 44/115 (38%) followed by papillary micro-carcinoma (n=30/115, 26%) and follicular variant of papillary carcinoma (n=18/115, 15.6%). Out of the 30 micro-carcinoma cases, 18 were diagnosed incidentally in thyroids operated for multi-nodular goiter. Immunohistochemical marker CK-19 was positive in 29/31, HBME-1 and HMW-CK in 15/15 cases; CEA was in one case where it was reported negative. Immunohistochemical stains were useful in cases with atypical /doubtful morphology.