Sameer Al Diffalha

An isolated intestinal duplication cyst masquerading as a mucinous cystic neoplasm of the pancreas: A case report and review of the literature

Highlights • Intestinal duplications cysts are rare congenital anomalies that can occur throughout the gastrointestinal tract.• Isolated intestinal duplication cysts can present with vague abdominal complaints.• Diagnosis can be challenging even with imaging.• Our clinical workup was suggestive of a mucinous cystic neoplasm (MCN) of the pancreas.• This represents the first reported case of an enteric duplication cyst that mimicked an MCN of the pancreas.

NUT Midline Carcinoma: A Rare Malignancy.

Nuclear protein of the testis (NUT) midline carcinoma can present in the head, neck, and mediastinum. In general, it presents in young adult men and has a poor prognosis. We report on a case of NUT midline carcinoma of the mediastinum in a man 27 years of age without any prior malignancy. Due to the location of the tumor, mediastinal lymphoma and germ cell tumor were initially considered; however, immunohistochemistry was performed using NUT antibody that revealed it to be NUT midline carcinoma. Although guidelines exist for squamous cell carcinoma of the head, neck, and mediastinum, no such specific guidelines are available for NUT midline carcinoma, which looks morphologically similar to squamous cell carcinoma but behaves more aggressively and carries a poor prognosis.

Invasive Breast Carcinoma Tumor Size on Core Needle Biopsy: Analysis of Practice Patterns and Effect on Final Pathologic Tumor Stage

Introduction In the absence of nodal metastasis, pathologic tumor (pT) size remains one of the most important factors in adjuvant treatment decisions and patient prognosis in breast cancer. The aim of this study was to evaluate the effect of core needle biopsy (CNB) tumor size on final pT stage. Materials and Methods Our information system was searched to identify all patients who underwent excisional procedures for invasive breast carcinoma from January 1, 2014 to December 31, 2015. The tumor size on CNB and final excision, the number of cases in which the CNB size was larger, and the percentage of cases in which using the CNB tumor size changed the final pT stage were recorded. Results From 1380 primary breast excisions/mastectomies, a total of 870 cases were included. In 82 (9.4%) the CNB tumor size was larger (63 of 82 cases) or no residual tumor was identified on excision (19 of 82 cases). From these 82 cases, 40 (48.7%) were properly staged on the basis of CNB tumor size, 16 (19.5%) were not staged, and 26 (31.7%) were staged using the final excision tumor size. Change in stage occurred in 7 of these 26 patients. Conclusion Our study revealed that in most cases, the largest tumor size is found in the excision/mastectomy specimen. However, in 9.4% (82 of 870), the CNB contains the most accurate tumor size for pT staging. On the basis of our results, including the largest linear tumor extent on the CNB report is recommended. Micro‐Abstract In this study we evaluated the effect of core needle biopsy (CNB) tumor size on final pathologic tumor (pT) stage. The laboratory information system was retrospectively reviewed for breast excisional specimens. In 82 of 870 cases (9.4%) the CNB contains the most accurate tumor size for pT staging. Including the largest linear tumor extent on the CNB report is recommended.

CD133 Expression as aHelicobacter pylori-independent Biomarker of Gastric Cancer Progression

Background/Aim: Gastric adenocarcinoma is the fourth most common cancer worldwide. While gastric cancer prevalence varies globally and incidence rates are decreasing in the West, many cases continue to be diagnosed at an advanced stage and the 5-year survival rate still falls below 30%. Early treatment of gastric cancer by endoscopic and/or surgical therapy may decrease mortality; yet reliable, universally applicable biomarkers for early detection of gastric cancer have still not been established. Materials and Methods: The present work compares the expression of CD133 (prominin-1), a potential biomarker of disease progression in gastric cancer, between independent cohorts of H. pylori (+) and H. pylori (−) patients at each respective stage of carcinogenesis. H. pylori (−) patients (N=45) who underwent gastric biopsy at the Moffitt Cancer Center (MCC) in Tampa, Florida, and H. pylori (+) patients (N=59) who underwent gastric biopsy at the Instituto de Patologia Mejia Jimenez (IPMJ) in Cali, Colombia were evaluated and immunostained for CD133. Results: A statistically significant increase in CD133 expression (in terms of the Allred score) was observed between all stages of progression (normal mucosa, inflammation/metaplasia, low-grade dysplasia and gastric adenocarcinoma) for each respective patient cohort. No statistically significant difference in CD133 expression at each respective stage of disease was observed between the H. pylori-positive and negative-cohorts. Conclusion: The observation of distinct stepwise increases in CD133 expression in both patient cohorts, and the lack of any significant difference between groups, suggests that CD133 expression may serve as a biomarker for early detection of gastric cancer independent of bacterial status and strain, and corresponding differences in disease histomorphology and classification. This warrants further validation on larger independent cohorts across multiple geographic regions and incorporating multiple bacterial strain types.

Neuroendocrine Tumors (NETs) of the Mediastinum and Thymus

Neuroendocrine tumors (NETs) of the mediastinum and thymus are rare and are usually discovered incidentally. Rosai and Higa were the first to acknowledge the existence of carcinoid tumors in the thymus and to separate them from more common tumors arising in this location, such as thymoma. The source of the primary NETs of the thymus has been proposed that they are derived from Kulchitsky cells. In this chapter we discussed the World Health Organization (WHO) classification of the NETs. We also spotlighted on some chromosomal imbalances that have been found by investigators in the most recent molecular biology literatures of the thymic NETs, as gain of chromosome (Xp, 7p, 7q, 11q, 12q, 20q, and 19p) and loss (6q, 6p, 4q, 3p, 10q, 11q, and 13q). Losses of heterozygosity (LOH) at chromosome 1p and loss of chromosomes 3, 9p21, and Y have been also reported. At the end of this chapter, we discussed the up-to-date prognosis, management, response evaluation, and follow-up of the patient.