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Among 527 patients with thyroid disease who underwent surgery at our hospital during a 20-year period, 2 (0.4%) had tuberculous thyroiditis mimicking carcinoma. The first patient was a 44-year-old man with a solitary thyroid nodule and the second was a 24-year old man with a thyroid abscess. The unexpected diagnosis was made postoperatively and was based on histological findings in both patients. No primary focus was found elsewhere in either patient, and both responded to antituberculous chemotherapy. Although the diagnosis is usually based on examination of resected specimens, recent reports indicate that find-needle aspiration cytology is a cost-effective technique of diagnosing thyroid tuberculosis. A review of 35 cases reported in the English literature is also discussed.

Increasing evidence suggests the possibility of relevant molecular differences between cancers from different ethnic groups. This study uses gene expression profiling by quantitative real time polymerase chain reaction (qRT-PCR) to identify "intrinsic" subtypes in a Saudi population of breast cancers and compares the distribution of subtypes to the more commonly profiled Caucasian population. In addition, the immunohistochemical profile of breast cancers was correlated to the gene expression analysis. Discrepancy rate of 39% in subtype prediction between gene expression and immunohistochemical profile of the tumors was noticed. Most of this variation was in the luminal subtype. Frequency of HER2+ subtype in the Saudi cases was high (28%) by both the immunohistochemistry (IHC) and the qRT-PCR classification. Triple-negative tumors comprised 39% while only 11% showed a basal-like profile. Analysis of larger cohort of patients is needed to determine the molecular taxonomy of breast cancer in the Saudi population and the benefits from the diagnostic classification developed in the West.

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In 2016, the grading criteria for Gleason scoring (GS) have been updated in the WHO classification of tumors of the prostate, and a new set of grade groups (GG) was introduced. As the inter-observer discordance is a well-known concern in Gleason grading before the update and no reproducibility study testing the grade groups exists, we planned to evaluate the inter-observer agreement of the most updated grading system. Four pathologists assessed 126 cores of prostatic carcinoma, and Kappa (k) test was calculated. The agreements for both GS and GG were substantial (k = 0.753 and 0.752; respectively). Discerning GG 2 from 3 also attained reasonable outcome (k = 0.675). Based on our results, the updated grading system seems to be reproducible, with satisfactory inter-observer concordance rate.

IntroductionIn this article, we report 7 novel KRAS gene mutations discovered while retrospectively studying the prevalence and pattern of KRAS mutations in cancerous tissue obtained from 56 Saudi sporadic colorectal cancer patients from the Eastern Province.MethodsGenomic DNA was extracted from formalin-fixed, paraffin-embedded cancerous and noncancerous colorectal tissues. Successful and specific PCR products were then bi-directionally sequenced to detect exon 4 mutations while Mutector II Detection Kits were used for identifying mutations in codons 12, 13 and 61. The functional impact of the novel mutations was assessed using bioinformatics tools and molecular modeling.ResultsKRAS gene mutations were detected in the cancer tissue of 24 cases (42.85%). Of these, 11 had exon 4 mutations (19.64%). They harbored 8 different mutations all of which except two altered the KRAS protein amino acid sequence and all except one were novel as revealed by COSMIC database. The detected novel mutations were found to be somatic. One mutation is predicted to be benign. The remaining mutations are predicted to cause substantial changes in the protein structure. Of these, the Q150X nonsense mutation is the second truncating mutation to be reported in colorectal cancer in the literature.ConclusionsOur discovery of novel exon 4 KRAS mutations that are, so far, unique to Saudi colorectal cancer patients may be attributed to environmental factors and/or racial/ethnic variations due to genetic differences. Alternatively, it may be related to paucity of clinical studies on mutations other than those in codons 12, 13, 61 and 146. Further KRAS testing on a large number of patients of various ethnicities, particularly beyond the most common hotspot alleles in exons 2 and 3 is needed to assess the prevalence and explore the exact prognostic and predictive significance of the discovered novel mutations as well as their possible role in colorectal carcinogenesis.

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