An entity that should be kept in mind: Synchronous gastrointestinal stromal tumor encountered in resection materials obtained for the detection of intra-abdominal malignancies.

OBJECTIVE: Gastrointestinal stromal tumors (GISTs), often sporadic, arise from interstitial Cajal cells of the gastrointestinal tract or their stem cell-like precursors. Apart from tumor-associated syndromes, it has been reported that GISTs are also associated with other tumors. There is no clear information about the etiology of these synchronous tumors. In this study, we wanted to present the clinicopathological features of 13 cases diagnosed as synchronous GIST with other tumors. METHODS: Demographic characteristics of the cases, risk of progressive disease score, tumor localization, size, and the mitotic activity of tumors along with survival status were evaluated. RESULTS: Thirteen of 101 cases diagnosed with GIST had a primary tumor synchronous with GIST. Synchronous GISTs were located in the stomach and small intestine. Most of the cases were detected incidentally in the intraoperative and post-operative periods. Risk scores for progressive disease were categorized as low (n=1), very low (n=1), and no risk (n=11). Non-GIST tumors were located in the stomach, transverse colon, left colon, rectum, gallbladder, kidney, and retroperitoneal space. Histological tumor types were adenocarcinoma, diffuse large B-cell lymphoma, mesothelioma, and neuroendocrine tumor. Life expectancy was found to be significantly lower in synchronous GISTs. CONCLUSION: In cases operated for non-GIST tumors, the possibility of incidental detection of GIST should always be kept in mind.

Intriguing Localisation of "Pacinian Neuroma'' Diagnosed at Intraoperative Consultation during Whipple Procedure.

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The importance of FISH signal cut-off values for 9p21 deletion in malignant pleural mesothelioma: Is it underestimated?

Malignant mesothelioma (MM) is an aggressive cancer with a poor prognosis. The most common genetic alteration in MM is the deletion of the INK4a/ARF locus, which encodes the p16 protein and is located on the short arm of chromosome 9 (9p21). Recently, it has been shown that homozygous deletion of 9p21 has both diagnostic and prognostic significance in MM. It is a known fact that, to interpret fluorescence in situ hybridization (FISH) signals, a cut-off value for each probe should be determined for a correct diagnosis. To our knowledge, there is no consensus or confirmed protocol for cut-off values to evaluate FISH signals in MMs. Therefore, the aim of our research was to address 9p21 deletion status and p16 expression profiles of MM by determining our own cut-off values and the effectiveness of using p16 negativity and 9p21 deletion as markers for differentiating MMs from benign mesothelial proliferations in 114 cases. We established a cut-off value for the detection of 9p21 deletion by using 13 benign reactive cases (6 reactive mesothelial hyperplasias and 7 chronic fibrinous pleuritis cases) and found between 0-7%. According to our calculations, homozygous deletion was defined by loss of both p16 gene signals in at least 13.3% of the nuclei that showed at least 1 signal for the CEP 9 probe. Our FISH results showed homozygous 9p21 deletion in 82 of the 114 cases of MM (71.9%), and p16 expression was negative in 75 of the 114 cases (65.8%). The correlation between loss of p16 protein expression and 9p21 deletion was statistically significant. Among the p16-negative cases, 86.7% also had the 9p21 deletion. The combined examination of the 9p21 deletion and loss of p16 expression is helpful for diagnostic purposes, but because the FISH method is an expensive technique and loss of p16 expression is not specific for mesotheliomas, p16 negativity can guide practitioners to eliminate cases that require further investigation by FISH. The variability in the significance of 9p21 homozygous deletion results from inconsistencies among different institutes, suggesting that each institute should establish its own cut-off value using reactive mesothelial proliferations. Alternatively, global studies are needed to assess cut-off values.

Osteoid Osteoma at the Proximal Diaphysis of the Fifth Metatarsal.

The foot is rarely the focus of osteoid osteoma, and only a few of those cases are related to the fifth metatarsal. The present case demonstrates that atypical symptoms with suspicious findings on plain radiographs that are not associated with trauma must be analyzed carefully to determine the nature of the lesion and perform the precise treatment to obtain and sustain the cure. A 29-year-old man presented to the outpatient clinic with a 2-year history of chronic pain in the lateral aspect of his left forefoot. The onset was not related to trauma, surgery, local infection, osteomyelitis, or another entity regarding the proximal fifth metatarsal. The patient noted that the pain was aggravated at night and typically subsided with the use of salicylates or other nonsteroidal anti-inflammatory drugs. Initial plain radiographs demonstrated cortical thickening and a lytic lesion at the proximal diaphysis of the fifth metatarsal. Because the pain relief was transient, we suspected an osteoid osteoma lesion, and subsequent magnetic resonance imaging manifested pathognomonic signs of subperiosteal osteoid osteoma. Diagnosis was followed by planning of the surgery that ended the patient's symptoms.

Bilateral Optic Pathway Ganglioglioma: The Fifth Case in the Literature.

Gangliogliomas are mixed tumors which contain both glial and neuronal elements. The optic pathway is a very rare location for gangliogliomas, with less than 23 cases reported in the literature. Bilateral involvement of the entire optic pathway was reported in only 4 cases before. Because of similar radiological appearance of other pathological entities such as gliomas and craniopharyngiomas, histopathological diagnosis is essential. We report a ganglioglioma case that involved both optic pathways. A 12-year-old patient suffering from visual deterioration for 6 months was evaluated. After a visual field test and radiological examinations, a microsurgical biopsy procedure was performed. Pathological examination revealed dysplastic/neoplastic ganglion cells and neoplastic glial cells, and the diagnosis was a World Health Organization (WHO) grade 1 ganglioglioma. The patient is scheduled for adjuvant radiotherapy with the hope of prevention of progression.

The effects of sodium-2-mercaptoethanesulfonate application on the neural and neurovascular tissues: An experimental animal study.

BACKGROUND: Sodium-2-mercaptoethanesulfonate (MESNA) is a protective agent that is also used as "a chemical dissector" in various surgical fields. The aim of this study is to evaluate the toxic effects of MESNA on neural and neurovascular structures based on a morphological analysis and examine its safety in neurotological applications. METHODS: Three groups of guinea pigs were used as subjects. MESNA solution (50 and 100%) and saline solution were applied to the subarachnoid space over the brain tissue via a middle fossa approach of study and control groups, respectively. Effects of MESNA were assessed by means of light microscope. McNemar Chi-square test was used to evaluate the histopathological findings. Statistical significance of P < 0.05 was taken as criterion. RESULTS: No morphological changes were observed on vascular and neural structures in the study groups in both concentrations, compared to the control group. CONCLUSIONS: On a morphological basis, a single application of MESNA does not cause any morphological changes that indicate a toxicity in neural and neurovascular structures.

Lycopene has reduced renal damage histopathologically and biochemically in experimental renal ischemia-reperfusion injury.

BACKGROUND: The present study aimed to investigate whether the inflammatory and antioxidant lycopene has a therapeutic effect against renal ischemia/reperfusion (I/R) injury. MATERIALS AND METHODS: In this study, 24 Wistar-Albino rats, weighing from 200 to 250 g, were divided into four groups. All rats underwent median laparotomy under anesthesia. No procedures were performed in the control group (Group C), whereas 100 mg/kg lycopene was administered by gavage in the lycopene group (Group L). The arteries of both kidneys were clamped for 45 min in the ischemia group (Group I), whereas 100 mg/kg lycopene was administered by gavage 30 min before clamping renal arteries, and ischemia was performed in the treatment group (Group T) rats. For all rats, blood samples and renal tissues were collected at 6 h of reperfusion. Samples were used to examine serum BUN, creatinine, MDA and GSH levels, and the renal tissues were used to examine MDA and GSH levels, and renal histopathologies. RESULTS: The treatment group had statistically significant lower serum MDA levels, histopathological tubular vacuolization, loss of brush border and tubular dilatation (p < 0.05), whereas serum BUN, creatinine, tissue MDA, and tissue and serum GSH levels were improved in favor of the treatment group, even though it was not statistically significant (p > 0.05). CONCLUSION: The present study demonstrated that lycopene, which was administered prior to renal I/R injury, prevented renal damage through biochemical and histopathological parameters.