Distinguishing squamous cell carcinoma (SCC) from keratoacanthoma (KA) by histopathological features may not be sufficient for a differential diagnosis, as KAs may, in some cases, imitate well-differentiated SCCs. In this study, we investigated whether the expression of the p16, p21, p27, p53 genes and a Ki-67 proliferation index are useful in distinguishing between these two tumors. Cross-sectional study. Immunohistochemistry was used to investigate the expression of the p16, p21, p27, p53 genes and the Ki-67 proliferation index was investigated in well-differentiated SCC with KA-like features (n=40) and KA (n=30). The results of all of the examined markers, except for p27 (p16, p21, p53, and Ki-67) were found to be significantly different between the SCC and KA samples (p<0.05). In well-differentiated SCC with KA-like features and KA cases where the differential diagnosis is difficult from a histopathological perspective, the use of p16, p21, p53 expression and a Ki-67 proliferation index can be useful for the differential diagnosis of SCCs and KAs.

Tuberculosis (TB) infection is still a challenging health issue, especially in developing countries. Diagnosing extrapulmonary infections, especially isolated organ involvement, is difficult in most cases even with the radiological, endoscopic, and histopathological examinations done for accurate diagnosis. Here we describe a case of isolated gastric TB with specific F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) findings mimicking gastric cancer/ lymphoma. A 20-year-old male patient was admitted to our hospital with abdominal pain in the epigastric region, weight loss, and fever especially at nights for 2 months. Physical examination was normal. Hemoglobin was 9.6 gm/dL; the patient had iron deficiency anemia. Upper gastrointestinal (GI) endoscopy was suggestive of gastric ulcer mimicking malignancy. F-18 FDG PET/CT revealed multiple hypermetabolic malignant lymphadenopathies in the abdomen and diffuse gastric wall thickening as linitis plastica and multiple hypermetabolic peritoneal implants in the omentum. Exploratory laparotomy was done for tissue diagnosis and exploration of the peritoneum for TB infection, lymphoma, and Crohn's disease to make differential diagnosis. Histopathology revealed granulomatous lymphadenitis with granulomas including giant cells, suspecting TB. Patient was put on antituberculosis treatment (ATT). After treatment, the complaints resolved, and he gained weight. Fusion PET/CT exhibited a complete response to ATT with no residual disease. According to our knowledge, this is the first report about F-18 FDG PET/CT findings in the diagnosis of isolated gastric TB. F-18 FDG PET/CT may provide help in the diagnosis and follow-up of isolated gastric TB in challenging cases.How to cite this article: Akdogan RA, Rakici H, Güngör S, Bedir R, Akdogan E. F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings of Isolated Gastric Tuberculosis mimicking Gastric Cancer and Lymphoma. Euroasian J Hepato-Gastroenterol 2018;8(1):93-96.

A giant cell Tumour of the tendon sheath (GCTTS) is a slow-growing benign Tumour originating from the synovial cells of the tendon sheath. It is the second most common Tumour of the hand. The aim of this study was to perform a retrospective clinicopathological evaluation of GCTTS cases and determine whether the proliferative activity of giant cell tumour of tendon sheath is related to its recurrence rate and local aggressiveness. The age, gender, Tumour location and diameter, treatment mode, Ki-67 proliferation index, mitotic rate, and recurrence were retrospectively evaluated in 35 patients diagnosed with GCTTS in the Department of Pathology, School of Medicine, Recep Tayyip Erdogan University between 2009 and 2014. Of the 35 GCTTS cases, 23 were female, and 12 were male. The mean age was 45 y (range 10-70). Sixteen tumours were located in the right hand and 14 in the left hand, and five were in the feet. The mean Tumour diameter was 2.3 cm (0.6-6 cm). All patients underwent marginal excision. The mean postoperative follow-up period was 4 y (range 28 months-5 y). Only six patients showed recurrence. In these cases, the site of GCTTS recurrence was the phalanx of the hand. The mean Ki-67 index in the recurrence cases was 6.5%, whereas it was 2.3% in those without recurrence. The Ki-67 proliferation index and mitotic activity were increased in recurrent cases compared to nonrecurrent cases. Therefore, these parameters may be helpful in predicting recurrence of GCTTS. However, adequate surgical excision and complete removal of the Tumour are important steps to minimize the recurrence rate.