often present with vague symptoms, but sometimes they cause upper gastrointestinal bleeding. Colorectal GISTs may manifest with lower gastrointestinal bleeding, colonic perforation, pain, obstruction or combination [4,10,11]. Also, fever or liver metastasis have described as first symp- toms . Rarely, they can present with intraperitoneal bleeding secondary to surface tumor ulteration [9,10]. Our patient presented clinically with pelvic pain and a pelvic mass diagnosed ultasonographically showing adequate fluid in the abdominal and pelvic cavities. The preopera- tive diagnosis was consistent with acute abdomen from a possible ovarian or uterine tumor. The ultrasonographic findings of GISTs are non-characteristic and therefore a preoperative presumptive diagnosis based on imaging is virtually impossible . In our patient, during the opera- tion, on the top of the mass a ruptured superficial vessel was found to bleed actively into the abdominal cavity and no other bleeding was indentified. It seems that the hemo- peritoneum resulting from a solid mass is secondary to passive blood congestion, subsequent rupture of a superfi- cial tumoral vessel and spontaneous internal bleeding . The postpartum hyperfibrinolysis might play a role for the bleeding of the mass. A diagnosis of GIST during preg- nancy is very uncommon [6-8]. Those few cases reported were symptomatic and found in the second half of the pregnancy, leading to an emergency cesarean section in one case due to fetal distress during laparotomy [6,7]. The delay in diagnosis of GISTs during pregnancy is normally due to the clinicians ’ reluctance to request diagnostic examinations during pregnancy and to the non-specific symptoms of the disease . Our patient had a normal delivery at term at a Private Maternity Hospital of Athens, because no obstruction of labor had occurred obviously. Possibly, the large mass arising from the small intestine and growing exophytically out into the peritoneal cavity
The bulk of the tumor was seen in an extragastric location with extensions into the gastrohepatic ligament and lesser sac. There was no evidence of direct invasion of the adjacent organs or perito- neal spread. No metastatic lesions or lympha- denopathy was seen in the abdomen or pelvis. The mass showed relative hypoattenuation on the precontrast images (Fig. 2A) and increased hetero- geneous enhancement in the portal phase (Fig. 2B) and prolonged enhancement in the equilibrium phase images (Fig. 2C). The radiologic findings were distinct from those of epithelial tumors and the possibility of a malignantgastrointestinalstromaltumor of the stomach was considered on CT. The mass was removed under general anesthesia by laparoscopic wedge resection of the stomach. During laparotomy there was a round and well demarcated mass arising from the lesser
tube with the patient in the supine position was carried out. The mediastinal pleura overlying the tumor were opened; the mass lesion was exposed after dissection of lower esophageal muscularis propria, superjacent diaphragm and adhesions of right lower lobe. The lesion appeared well vascularized and with a medium consistency. After careful dissection, the mass was enucleated. The tumor was a 8.0×7.5×6 cm, well encapsulated, firm mass involving the muscular layers of lower esophagus (Figure 2A). Microscopically, the tumor was composed of spindle cells with ill-defined cytoplasmic bor-
DPL is pathologically benign smooth muscle tumors in which nuclear atypia is uncommon and mitotic figures are scarcely seen ; however, some cases of DPL showed recurrent and malignant transformation [7–9]. Based on PubMed search from 1985 to 2018, malignant transformation has been reported in 19 cases and the prognosis for the patients is approximately 1 to 12 months. The cases with the histological images of high cell density, aggregated atypical nuclei, and frequent mitoses were diagnosed as malignancy. The mechanism of malignant transformation of DPL remains unknown [11, 12]. However, DPL with uterine leiomyomas has a low risk potential for malignant transformation, whereas DPL without exposure to estrogen, without uterine leio- myomas, and without ER and PgR expression may have Table 1 Immunohistochemical comparison of GIST and DPL
Gastrointestinalstromal tumors (GISTs) are potentially malignant mesenchymal tumors of the gastrointestinal (GI) tract and typically arise from stomach or small intestine in adults . These tumors frequently occur in the 50 to 60-year-old patients, without preference for gender . Patients are often asymptomatic or experience nonspecific symptoms including epigastric discomfort and pain, but some severe symptoms such as GI bleeding and ulcer-like symptoms may also occur . Loca- lization of GISTs in adrenal area is extremely rare that, as our knowledge, only a few cases have been reported to date [4-6]. The imaging characteristics of this entity are similar to those of hormonally inactive adrenal masses, leading to diagnostic difficulties. A definitive diagnosis could only be achieved through histopathological examination and immunohis- tochemical staining of the tumor. Here, we report a rare case of GIST disguising an adrenal tumor that was successfully resected laparo- scopically.
Gastrointestinalstromal tumors (GIST) represent the most frequent mesenchymal neoplasm of the GI tract. As reported by Nilsson et al., epidemiological data virtually are non existent regarding the true incidence and preva- lence of GIST. This is due to the previous lack of well defined pathologic criteria for GIST, varying nomencla- ture for GIST over the past few decades, and the finding that nearly 60% of all GIST have been diagnosed as benign tumors or tumors of uncertain malignant poten- tial, thus they are not reported to national cancer regis- tries. Therefore, Nilsson et al. analyzed the incidence and prevalence of GIST in a defined population, in a prov- ince of western Sweden. In that region the annual inci- dence of clinically detected GIST was estimated 14.5 per million inhabitants and the prevalence was 22.2 per mil- lion for very low risk GIST, 51.9 per million for low risk, 24.2 per million for intermediate risk, 22.2 per million for high risk and 8.7 per million for malignant GIST. GIST are defined as mesenchymal neoplasm expressing KIT protein, driven by KIT or PDGFRα (platelet derived growth factor alpha) mutations. They are regarded as derived from interstitial cells of Cajal (ICC). ICC are pace- maker cells that regulates peristalsis and have immu- nophenotypic and ultrastructural features of both smooth muscle and neural differentiation in varying degrees. ICC are KIT positive cells. Activation of KIT by mutations, causes Cajal cell proliferation and GIST.
Case presentation: A 30-year-old Caucasian ethnic Albanian woman from Kosovo presented with abdominal pain, nausea and vomiting. Subsequently, the tumor was detected in her small intestine, as an infiltrating mass approximately 10cm in diameter. The tumor was resected en bloc and duodenojejunal terminal-terminal anastomosis was performed. The tumor was a large, bulky, intramural mass, with fish-flesh to tan-brown appearance, as well as with foci of hemorrhage and necrosis. On histological examination the tumor showed transmural growth, deep infiltrative pattern and malignant feature, with mitotic count >5 per 50 high-power field, dense cellularity with plump spindle cells, and with eosinophilic cytoplasm within variably hyalinized and edematous stroma, skeinoid fibers (extracellular collagen globules) and foci of hemorrhage. In addition, the tumor was composed of areas with epithelioid morphology. The immunohistochemistry results showed high expression of proto-oncogene c-kit, CD117, CD34 and vimentin, whereas α -smooth muscle actin was focally positive. Desmin and S-100 protein were negative. Conclusions: Gastrointestinalstromaltumor should be included in the differential diagnoses of intestinal mesenchymal tumors presenting as a single mass in young female adults. Given that gastrointestinalstromal tumors in young adults represent a more heterogeneous group than gastrointestinalstromaltumor in pediatric cases, more effort should be made to investigate its pathogenesis and potentially more specific treatment.
revealed the negative correlation between NLR and RFS, the authors had to exclude patients who had received adju- vant imatinib therapy to reduce the bias in RFS. This means the patients enrolled in their study mostly had early-stage disease and low and moderate risk of recurrence. However, our work included patients with stage I to II disease with various malignant potential. As an unfavorable prognostic factor, elevated NLR was found to be a valuable predictive parameter for tumor staging in colorectal cancer patients. 23
We achieved an R0 resection in our patient, but given the size and presence of necrosis in the tumor adjuvant STI- 571 was started. There is no prospective data supporting the use of STI-571 in an adjuvant or neoadjuvant therapy after curative resection of GIST or EGIST. Yamamoto et al. suggests that the application of STI-571 could be a thera- peutic strategy for EGISTs since they have kit alterations . Todoroki et al. used STI-571 (300 mg/day orally) as adjuvant postoperative treatment in a 65-year-old female with a primary omental stromaltumor after R0 resection with a disease free follow-up at six months . The American College of Surgeons Committee on Cancer (ACOSOG) is currently leading a phase II trial to test the benefit of adjuvant STI-571 with 400 mg/day for one year in patients after complete resection of high-risk tumors primary GISTs. The risk of recurrence after resection of a primary GIST is high. Conventional chemotherapy has proven ineffective against GIST (less than 10% response). The use of adjuvant STI-571 is based on the assumption of highest impact on residual microscopic disease, despite a negative margin of resection of the primary tumor . STI-571 has demonstrated favorable response in more than half of patients with advanced and unresectable or metastatic GIST . There has been reported resistance to STI-571 in patients with metastatic or recurrent disease, to which there are no good therapeutics currently . Conclusion
Abstract: Esophageal cancer is mainly divided into squamous cell carcinoma and adenocarcinoma. Epidemiologically, the former contributes to 90% of worldwide esophageal cancer cases, while adenocarcinoma contributes to two- thirds of cases in developed countries. Although other rare types and collision with multiple histological types of tumors do occur in the esophagus, it is very rare for a gastrointestinalstromaltumor (GIST) to collide with an epi- thelial malignanttumor. To date, only three cases have been reported in the literature. The current study reported a 69-year-old male patient with squamous cell carcinoma and GIST in the middle esophagus. There was no merging of tissue components between these tumors. This study together with a literature review indicates that esophageal collision tumors have been increasingly reported in recent years. Histology and immunohistochemistry are needed to make a differential diagnosis. The exact oncogenic mechanism or the interaction of two independent neoplasms still remains to be determined, and further investigation, such as electron microscopy and genetic analysis, may help to elucidate the pathogenesis of the colliding tumors.
Even tumors located very close to the ampulla do not necessitate a duodenopancreatectomy, if they can be resected with an anastomosis just below the ampulla, as we did in the presented case. In order to avoid a stricture of the ampulla, we decided to do a lateroterminal anasto- mosis located opposite to the papilla. Other authors per- formed a papilloplasty and inserted a temporary stenting catheter into the papilla to avoid stenosis following a anastomosis located very close to the papilla . Even periampullary GISTs do not have to trigger duodenopan- createctomy. Cavallini reported the case of a periampul- lary GIST with a diameter of 3.5 cm that was treated by local excision and duodenal wall defect repair, preferring this more conservative procedure to a duodenopancreate- ctomy. The patient was free of recurrence 4 years after sur- gery . This underlines that we have to question the indication for duodenopancreatectomies for a tumor with potentially benign appearance. However, tumors of the duodenal bulb, and large tumors with high malignant potential, or tumors reaching into adjacent organs still make a duodenopancreatectomy necessary.
under 4 cm. Moreover, in a retrospective study of 207 pa- tients who underwent gastrectomy or esophagectomy for non-GIST neoplasms, 15 synchronous GISTs in the upper gastrointestinal tract of 11 (5.3 %) patients were found with an average size of 0.5 cm (0.1–4.0 cm) . After a median follow-up of 11 months (2–36 months), no patient experienced GIST recurrence. Synchronous GISTs that were incidentally found during the resection of other gastrointestinal neoplasms may not negatively affect long- term survival, although they often pose very low or low risk of malignant potential. Small GISTs (<2 cm) may be asymptomatic and nonmalignant when diagnosed but have a potential for malignant transformation. In the present study, there were five patients with intermediate/ high risk in the non-synchronous group, and they might more likely to experience tumor progression than that of patients with very low/low risk.
It is clear that NF1 affects almost every organ system in the body. Patients with NF1 have higher risk of developing cancer as compared to the general pop- ulation . Data from cohort studies on NF1 patients have indicated a 5% to 15% overall additional risk to develop cancer. Recent data from a prospective study shows an incremental risk, by a factor of 2.7, related to brain/CNS and connective tissue tumors . The involvement of the gastrointestinal tract has been reported on NF1 patients, in which benign alterations such as constipation and dysplasia and disorganization of the tunica muscularis and Auerbachs’s plexus of the colon, as well as malignant diseases, such as pancreatic, bowel, and liver neoplasms, were observed . The association between NF1 and tumors of neurogenic and neuroendocrine origin, such as meningioma, glioma, and pheochromocytoma, is well known . However, the association between NF1 and duodenal neuroendocrine tumors, though uncommon, has become more widely recognized. Patients with NF1 tend to develop peri-ampullary tumors, most commonly somatostatin-producing endocrine tumors .
exclusive mutations in Kit or PDGFRA receptor tyrosine kinase proteins play a central role in GIST pathogenesis [7-10]. This is clearly illustrated by the collected data from primary omental GISTs (Table 2). Mutually exclusive gain-of-function Kit or PDGFRA mutations represent in- frame deletions, point mutations, duplications or inser- tions. Mutations in the Kit juxtamembrane domain (exon 11) are the most common in GISTs of all sites, whereas a rare Kit extracellular domain (exon 9) Ala502-Tyr503 duplication is specific for intestinal GISTs. Mutations in PDGFRA have been identified in the juxtamembrane (exon 12), as observed in our case, and tyrosine kinase domains (exons 14 and 18), nearly exclusively in gastric GISTs, mostly epithelioid variants. Some Kit and PDGFRA mutations carry prognostic value. The Kit/PDGFRA tyro- sine kinase inhibitor Imatinib has been successfully used in the treatment of metastatic GISTs for more than 5 years [10,11]. Microscopic features are site-dependent and the majority (more than 85%) appears as spindle cell tumors [11,12]. However, only half of our collected omental GISTs appeared to be spindle cell tumors, the remaining being epithelioid and myxoid (Table 1). No correlation between prognosis and histologic type has been reported. On the other hand, it is well known that tumor size and mitotic activity are the best prognostic features . In our case, the tumor size and the mitotic activity expressed per 50 HPFs were 20 cm and 2, respectively. It is hardly predict accurately the risk for disease progression and malignant potential of our case, because of scarcity of the primary omental GIST. Based on the criteria advocated by Miettinen and Lasota, these two tumor parameters place the tumor in group 3b, at the intermediate risk ,
CT findings of GISTs are well described in the radiological literature [8-13]. Malignant GISTs are typically extralumi- nal, large (>5 cm), well-circumscribed, heterogeneous, centrally necrotic tumors. Such features contrast with the regular contours, homogeneous density, and intraluminal growth patterns that are characteristic of smaller benign GISTs. Thus, well-circumscribed tumors appear to be a feature of GISTs, as in our case, on CT imaging. Heteroge- neous density, on the other hand, was independent from tumor dimension. Heterogeneous density, pathologically concordant with hemorrhage, has been found in tumors less than 5 cm, despite the homogeneous densities found in the tumors bigger than 5 cm.
Currently, there is no accepted staging system for GISTs. Tumor size, location, mitotic rate, C-KIT and PDGFRA genotype are the major determinants of malignant poten- tial of the tumor which have significant impact on prog- nosis [20-22]. A practical grading system for GIST after surgical resection was proposed by Bucher et al.  including 5 minor (tumor size ≥5 cm, mitotic index ≥5 Abdominal CT scan: axial view showing an 8 cm in size antral
GISTs have an uncertain clinical behavior ranging from benign to frankly malignant, making the outcome totally unpredictable. Over the years, many factors have been examined, such as size, histomorphology, immunohisto- chemistry and molecular genetics. However, it is difficult to predict the malignancy potential. Thus, there is not an accepted staging system for GIST. Multiple parameters have been considered as predictors of malignancy. At present, size and mitotic count appear to be the most use- ful predictors of the malignant behavior . GISTs always have a malignant potential, even if they appear benign. Tumors <5 cm are usually low-risk, while those >5 cm are malignant. Even though size <5 cm is reassuring, we cannot always predict them as benign, as there is always the chance to metastasize . Furthermore, the mitotic count is a reliable parameter. Mitoses <5 per 50 high power fields (HPF), usually characterizes GISTs as benign. Duodenal stromal tumors is characterized as benign have <2 mitoses per 50 HPF, while the cutoff for ileal GIST is 5 mitoses per 50 HPF. It is important to point out that fifty HPF is the minimum number of HPFs neces- sary to generate an accurate index of proliferative activity . However, GISTs in stomach, measuring 5-10 cm, usually, have a good prognosis, as long as the mitotic count or Ki67 rate is low. On the other hand, small intes- tine tumors >5 cm behave in an aggressive way, regardless of the mitotic index. Finally, GISTs occurring anywhere, that measure >10 cm, tend to behave in a malignant way. Many studies  have indicated that there are several fea- tures, such as sclerosing that are related to a more favora- ble prognosis, while a hypercellular sarcomatous appearance predicts an aggressive behavior. In gastric tumors, diffuse nuclear atypia, coagulative necrosis and ulceration have been found to be prognostic unfavorable features while nuclear palisading and skeinoid fibers were favorable in a large series by Miettinen et al. . Immu- nohistochemical markers may be of importance in pre- dicting the malignant behavior of GISTs. Increased expression of cell cycle markers (MIB-I or Ki-67) have been linked to a less favorable prognosis in larger studies . P16 is a tumor suppressor gene that inhibits cell cycling by arresting cells in G1 before entry into the S phase. P16 has been found to be down-regulated in malig- nant GISTs in some studies  but the same down-regu- lation has been found to be a prognostically favorable variable in other studies . The National Institute of Health (NIH) Workshop, in 2001, suggested that a classi- fication of GISTs in terms of their relative risk of aggressive behavior, rather than as benign or malignant, seems to be necessary. The guidelines recommend classifying GISTs
Gastrointestinalstromaltumor (GIST) is the most com- mon primary mesenchymal tumor of the gastrointestinal tract, and the clinical behavior ranges from benign to malignant. Before the pathogenesis of GIST was under- stood, most GISTs were formerly diagnosed as leiomyo- blastomas and gastrointestinal autonomic nerve tumors (GANTs). GIST arises from interstitial cells of Cajal (ICC) and generally characterized to be immunohisto- chemically positive for KIT (CD117) and contains KIT- or PDGFRA-activating mutations [1, 4]. Based on the re- sults of population-based studies in Iceland and Sweden,
chance, and the patients usually present with gastrointestinal bleeding, which is often chron- ic or intermittent. In addition, they are often found in patients with anemia, constipation or obstruction. The current patient had an unex- plained anemia and seek for etiology in many other medical institutes before she came to our hospital. Both the characteristics and the tumor genesis of GISTs in patients with NF-1 are different from those of sporadic GISTs. GIST in NF-1 patients develops in the small intestine and has a tendency to form multiple lesions in most cases, although this patient has only one lesion in the jejunum with a metastatic mass in the liver. On the other hand, sporadic GIST occurs as solitary lesion, most commonly in the stomach . GIST associated with NF-1 has a better prognosis than sporadic GIST with the same size and stage . As c-kit gene muta- tion is rare in GIST with NF-1 , the mecha- nism of development of this GIST may be ex- plained by loss of heterozygosity of NF-1 gene , rather than a mutation of the c-kit gene. There are many Published reports of gastroin- testinal mesenchymal tumors in NF1 patients (Table 1).
Abstract: We analyzed clinicopathologically 12 gastric schwannomas. Patient ages ranged from 41 to 79 years (mean, 52 years; median, 59 years). They variably presented with gastric discomfort, bleeding, or rarely gastric out- let obstruction and many were incidental findings during other medical procedures. The maximum tumor diameters ranged from 1.0 to 5.4 cm (mean, 3.5 cm; median 3.8 cm). The typical histologic features included spindle cells with micro-trabecular architecture, focal nuclear atypia, and peritumoral lymphoid cuff. Median mitotic count was 1/50 high-power field. No malignant variants were recognized, and follow-up did not reveal recurrences or metastases. Immunohistochemically, all tumors were positive for S100 and SOX10, and most were also GFAP positive, whereas CD34 and NF were rarely positive. All tumors were negative for cytokeratin AE1/3, HMB45, c-kit, DOG1, smooth muscle actin, desmin, and synaptophysin. None of the tumors showed gastrointestinalstromaltumor-specific KIT or PDGFRA mutations. Gastric schwannoma is a distinctive form of peripheral nerve sheath tumor and it should be distinguished from gastrointestinalstromaltumor and other mesenchymal tumors of the gastrointestinal tract, especially clear cell sarcoma and metastatic melanoma.