Gastrointestinal stromal tumors, intramural leiomyomas, and leiomyosarcomas in the duodenum: a clinicopathologic, immunohistochemical, and molecular genetic study of 167 cases

Clinicopathological and Prognostic Features of Surgical Management in Duodenal Gastrointestinal Stromal Tumors

BACKGROUND AND OBJECTIVES

The rarity of duodenal gastrointestinal stromal tumors (DGIST) led to only limited data being available on their management and prognosis. We retrospectively analyzed the clinicopathological features, surgical treatments, adjuvant therapy, and prognosis of DGIST.

METHODS

Sixty-one patients were identified at diagnosis of primary DGIST from February 2005 to December 2015. One hundred twenty six patients with small intestinal gastrointestinal stromal tutors (GIST) were selected as control groups. Survival analyses were calculated using the Kaplan-Meier method.

RESULTS

Three- and five-year recurrence/metastasis-free survival rates of patients with DGIST were similar to those of patients with small intestinal GIST (p > 0.05 for all). Out of 61 cases with DGIST, 45 patients were treated with Limited Resection (LR). Sixteen patients were treated with Pancreaticoduodenectomy (PD). The 3- and 5-year recurrence/metastasis-free survival rates of the PD group and LR group were of no significant difference (p > 0.05 for all). Univariate analysis indicated that factors including surgical approaches, mitotic count, size, and risk grades were significantly associated with recurrence/metastasis-free survival (log-rank test, p < 0.05). Multivariate analysis demonstrated that the mitotic count was independently correlated with a worse recurrence/metastasis-free survival.

CONCLUSIONS

Patients with radical resected DGIST had a favourable prognosis, which is similar to that of small intestinal GIST. Both LR and PD were optimal choices for treating DGIST.

Recurrent Gastrointestinal Stromal Tumors in the Imatinib Mesylate Era: Treatment Strategies for an Incurable Disease

Introduction

Recurrence of gastrointestinal stromal tumors (GISTs) after surgical resection and imatinib mesylate (IM) adjuvant therapy poses a significant treatment challenge. We present the case of a patient who underwent surgical resection after recurrence and review the current literature regarding treatment.

Case Presentation

A 58-year-old man with a large intra-abdominal jejunal GIST was treated with complete surgical resection followed by IM. The patient experienced disease recurrence 3.5 years later and underwent IM dose escalation and reresection.

Conclusion

Current strategies to treat recurrent GIST include dose escalation, modifying adjuvant tyrosine kinase inhibitor therapy, and surgery. High-level evidence will be required to better define the combinatory roles of tyrosine kinase inhibitor therapy, guided by molecular profiling, and surgery in the management of recurrent GIST.

Surgery for Duodenal Gastrointestinal Stromal Tumors: A Single-Center Experience

BACKGROUND

The duodenal gastrointestinal stromal tumors (GISTs) are an extremely rare subset of GISTs. The optimal surgical procedure remains not well defined.

AIMS

We assessed the surgical approach and long-term outcomes of patients with duodenal GISTs who underwent limited resection (LR) versus pancreaticoduodenectomy (PD).

METHODS

From November 2005 to January 2016, 64 consecutive patients with duodenal GISTs in a single center were retrospectively analyzed. Overall survival (OS), recurrence-free survival (RFS), and perioperative outcomes were analyzed according to the different surgical type.

RESULTS

A total of 41 patients (64.1%) underwent LR, while 23 patients (35.9%) underwent PD. All patients had negative surgical margins (R0). Median tumor size was larger for PD (6 cm) versus LR (4 cm) (P = 0.041). PD also had more complications than LR (PD, 69.6 vs. LR, 31.7%) (P = 0.002). The 3-year and 5-year RFS was 62.9 and 44.3%, respectively. The 3-year and 5-year OS was 85.7 and 59.5%, respectively. The multivariate analysis demonstrated the only unfavorable predictive factor was tumor size >5 cm for RFS and OS. Although the complication rate in the PD group was higher than in the LR group, OS and RFS were not affected by the complication (P = 0.492 for OS, P = 0.512 for RFS). PD versus LR was not associated with RFS and OS. Adjuvant imatinib mesylate (IM) did not improve the survival of the patients after operation.

CONCLUSIONS

Survival of duodenal GISTs is mainly dependent on tumor biology rather than surgical procedure. LR should be the surgical procedure of choice for duodenal GISTs when technically feasible and no anatomical constrains. LR shows comparable survival and lower risk of postoperative complications compared by PD. The administration of IM both as adjuvant and neoadjuvant therapy for duodenal GISTs needs large population and prospective study to evaluate its effect.

Surgical Pathology of Gastrointestinal Stromal Tumors: Practical Implications of Morphologic and Molecular Heterogeneity for Precision Medicine

Gastrointestinal stromal tumor (GIST), the most common mesenchymal neoplasm of the gastrointestinal tract, exhibits diverse histologic and clinical manifestations. With its putative origin in the gastrointestinal pacemaker cell of Cajal, GIST can arise in association with any portion of the tubular gastrointestinal tract. Morphologically, GISTs are classified as spindled or epithelioid, though each of these subtypes encompasses a broad spectrum of microscopic appearances, many of which mimic other histologic entities. Despite this morphologic ambiguity, the diagnosis of GIST is aided in many cases by immunohistochemical detection of KIT (CD117) or DOG1 expression. The natural history of GIST ranges from that of a tumor cured by surgical resection to that of a locally advanced or even widely metastatic, and ultimately fatal, disease. This clinicopathologic heterogeneity is paralleled by an underlying molecular diversity: the majority of GISTs are associated with spontaneous activating mutations in KIT, PDGFRA, or BRAF, while additional subsets are driven by genetic lesions-often inherited-of NF1 or components of the succinate dehydrogenase enzymatic complex. Specific gene mutations correlate with particular anatomic or morphologic characteristics and, in turn, with distinct clinical behaviors. Therefore, prognostication and treatment are increasingly dictated not only by morphologic clues, but also by accompanying molecular genetic features. In this review, we provide a comprehensive description of the heterogenous molecular underpinnings of GIST, including implications for the practicing pathologist with regard to morphologic identification, immunohistochemical diagnosis, and clinical management.

Gastrointestinal stromal tumours of the oesophagus: a clinicopathological and molecular analysis of 27 cases

AIMS

Gastrointestinal stromal tumours (GISTs) may arise anywhere in the gastrointestinal tract, but are rare in the oesophagus. We describe the clinical, pathological and molecular characteristics of 27 primary oesophageal GISTs, the largest series to date.

METHODS AND RESULTS

DNA was extracted and exons 9, 11, 13 and 17 of KIT, exons 12, 14 and 18 of PDGFRA and exon 15 of BRAF were amplified and sequenced. Oesophageal GISTs occurred in 14 men and 13 women aged between 22 and 80 years (mean: 56 years). All 27 cases were immunohistochemically positive for KIT, and 92 and 47% co-expressed CD34 or smooth muscle actin, respectively. Fifteen (71% of analysed cases) harboured KIT exon 11 mutations and one case each had a mutation in KIT exon 13 (K642E) or BRAF exon 15 (V600E). Long-term follow-up data (median, 96.5 months) were obtained for 20 cases; two patients had metastases at presentation and seven had developed local recurrence and/or metastasis after surgery. A large tumour size (≥ 10 cm), high mitotic rate (> 5/5 mm² ), presence of a deletion mutation in KIT exon 11 involving codons 557-558 and a positive microscopic margin were associated with recurrence and metastasis. The KIT mutations identified in oesophageal GISTs are similar to those observed in gastric GISTs.

CONCLUSIONS

Complete surgical resection with clear margins is recommended, if technically feasible, and genotyping can help to improve diagnosis and further patient management in oesophageal GIST.

Organ-preserving surgery for locally advanced duodenal gastrointestinal stromal tumor after neoadjuvant treatment

This report aims to investigate the feasibility and outcomes of neoadjuvant imatinib mesylate (IM) administration followed by organ-preserving surgery (OPS) for patients with locally advanced duodenal gastrointestinal stromal tumor (GIST). Between 2012 and 2015, 10 consecutive patients with locally advanced duodenal GISTs were treated in Peking University Cancer Hospital. Multidisciplinary assessment was implemented, and pancreaticoduodenectomy (PD) was initially indicated as the most probable surgical procedure for all 10 patients. To attempt to create opportunities of less-invasive OPS for patients, neoadjuvant IM was administered followed by radical resection. All data were prospectively collected, and the short- and long-term outcomes of the treatment strategy were analyzed. The median treatment duration of neoadjuvant IM administration was 5 mo (range 2-18 mo). Significant tumor shrinkage (from 9.2 to 5.9 cm on average) was observed in all patients, and partial response was achieved in eight patients (80.0%) according to the Response Evaluation Criteria in Solid Tumors 1.1. No tumor perforation occurred, and nine patients (90.0%) underwent successful OPS with four different operation types. Postoperative morbidity rate of OPS was 55.6% (5/9), and no mortality occurred. After a median follow-up of 36 mo, one patient developed multiple distant metastases, but no local recurrence was observed. For long-term follow-up, patients who underwent OPS did not show any degradation in quality of life, whereas the patient who underwent PD suffered weight loss of ~10 kg. In conclusion, in patients with locally advanced duodenal GISTs, neoadjuvant IM administration followed by OPS is a feasible treatment strategy which leads to favorable short- and long-term outcomes.

Mesenteric Leiomyoma in Infancy

A 10-year-old female presented with a palpable mass occupying the entire abdomen. Computerized tomography scan showed a large expansive lesion measuring 22 cm × 20 cm × 13 cm. The mass was resected and the diagnosis of leiomyoma was made from immunehistochemical findings. Mesenteric leiomyoma is an uncommon tumor among gastrointestinal stromal tumors.

Robotic Versus Laparoscopic Gastric Resection for Primary Gastrointestinal Stromal Tumors >5 cm: A Size-Matched and Location-Matched Comparison

This study compared robotic (RR) and laparoscopic resection (LR) for primary gastrointestinal stromal tumors (GISTs) of the stomach >5 cm. Twelve consecutive patients who underwent RR from 2012 to 2015 were matched for tumor size and location with 24 patients who underwent LR from 2000 to 2012. The median tumor size was 7.1 cm (range, 5.5 to 11.5). GISTs were resected by wedge resection (91.7%) or distal gastrectomy. The median RR operative time was longer than that of LR (162.5 vs. 130 min, respectively; P=0.004). Only 1 LR patient required conversion. The time to flatus and hospital stay were similar between groups. Overall, 3 patients developed minor postoperative complications that were medically treated. Mortality was nil. All resections were R0. No difference was observed in the incidence of recurrence. RR was significantly more expensive (+21.6%) than LR. RR appears to be safe and feasible for GISTs>5 cm, but is associated with longer operative times and greater costs.

Patterns of care and clinical outcomes in primary oesophageal gastrointestinal stromal tumours (GIST): A retrospective study of the French Sarcoma Group (FSG)

BACKGROUND

Oesophageal GIST (ESOGIST) are very rare tumours requiring special consideration regarding diagnosis, surgical management, and perioperative treatment.

METHODS

A retrospective study was conducted across 9 centres in the French Sarcoma Group (FSG) to characterize all patients in the years 2000-2014.

RESULTS

Seventeen patients (pts) with primary localized ESOGIST were identified, with median age 69 years (36-81) and 11 females. Eight tumours (T) occurred in the lower third of the oesophagus, five in the oesophageal gastric junction, two in the superior third, and two in the middle third. All pts underwent oesophagoscopy and/or endoscopic ultrasound (EUS) and CT scan. Fifteen had EUS guided biopsy. Nine pts received Imatinib (IM) as initial treatment resulting in six PR, three SD. Tumours were resected in nine pts (53%) (7 upfront, 2 after IM); via enucleation in four (44%) [median size 4 cm], oesophagectomy in five (56%) [median size 10 cm]. Resections were R0 in three pts (33%), R1 in six (66%). Eight pts (47%) had no tumour resection, and one patient was never treated. Six pts received adjuvant IM. With a median follow-up of 24 months (7-101), 11 pts are alive (64.7%), five died (29.4%), one was lost to follow-up. Two pts of 4 pts relapsed following enucleation.

CONCLUSIONS

ESOGIST can be reliably identified pre-operatively by EUS-guided biopsy. Surgery for ESOGIST is either enucleation or oesophagectomy depending on tumour size, location, and patient's individual surgical risk. Preoperative IM therapy could improve resectability and should be considered if surgery is contraindicated or would lead to negative impact on the functional status of the patient.

Heavily calcified gastrointestinal stromal tumors: Pathophysiology and implications of a rare clinicopathologic entity

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, and are characterized by a broad spectrum of clinical, histological and molecular features at presentation. Although focal and scattered calcifications are not uncommon within the primary tumor mass, heavy calcification within a GIST is rarely described in the literature and the clinical-biological meaning of this feature remains unclear. Cases with such an atypical presentation are challenging and may be associated with diagnostic pitfalls. Herein, we report a gastric GIST with the unusual presentation of prominent calcifications that was identified incidentally on imaging during a post-trauma diagnostic work-up. The patient underwent laparoscopic surgery with a radical resection of the mass, which was subsequently characterized by histological analysis as spindle-shaped tumor cells, positive for CD117/c-KIT, CD34 and DOG1, and with calcified areas. Given the intermediate risk of recurrence, no adjuvant therapy was recommended and the patient underwent regular follow-up for 22 mo, with no evidence of relapse. Our case can be considered of interest because of the rarity of clinical presentation and the uniquely large size of the GIST at diagnosis (longest diameter exceeding 9 cm). In closing, we discuss the pathophysiology and clinical implications of calcifications in GISTs by reviewing the most up-to-date relevant literature.

Urgency surgical treatment for duodenal GISTs: analysis of aged patients and review of the literature

INTRODUCTION

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal neoplasms (85%) of the gastrointestinal (GI) tract; duodenal GISTs constitute 3-5% of all GISTs and represent 10-30% of all malignant tumours of the duodenum. Rarely, patients present severe bowel obstruction, perforation or severe bleeding. The radical resection with complete removal of the tumour remains the main therapeutic approach. We performed a local resection in patients with suspected GIST admitted for emergency treatment for GI bleeding.

CASES

We present three cases of patients admitted for GI bleeding. The cause could be a GIST bleeding. In all cases, local resection was performed without a pancreaticoduodenectomy. Histological examination on surgical preparations showed that in two cases it was a GIST and in one case, it was a leiomyoma.

DISCUSSION

Surgery remains the treatment of choice in the case of a GIST primitive without evidence of metastases, even for patients who are hospitalized for a bleeding emergency. Wide resections are not needed; it is important to remove completely the disease. In the case of duodenal GIST, it is important to get negative margins near the head of the pancreas, and this could take a PD. According to our experience and to the literature review, we believe that if the duodenal papilla or the periampullary region is not interested, you must perform a local resection. This is also because non-malignant tumours may present as GISTs and in these cases it is not recommended to run a PD.

CONCLUSION

The treatment of choice for duodenal GISTs is complete surgical resection with negative resection margins. When the papilla or the periampullary region is involved we choose to perform pancreaticoduodenectomy; otherwise it is better to perform a local resection. In fact, local resection has lower morbidity and mortality, with a comparable outcome.

Neoadjuvant Chemotherapy for Duodenal GIST: A Case Report

The principal treatment for gastrointestinal stromal tumors (GISTs) is surgical; and complete excision is important, but cannot always be achieved. For such cases, neoadjuvant chemotherapy (NAC) with imatinib mesylate (IM) has been recommended. A case of a GIST of the second portion of the duodenum for which pancreatoduodenectomy was indicated, and for which partial resection was made possible as a result of cytoreduction by IM NAC, is reported. A 64-year-old man with pancytopenia due to hepatic cirrhosis caused by hepatitis C infection received repeated blood transfusions because of anemia of unknown origin starting 2 years earlier. Most recently, the patient had melena with hemoglobin of 5.1 mg/dL. Diagnostic imaging showed a solid tumor, 55 × 48 × 65 mm3, in the second portion of the duodenum showing mainly extramural development. Endoscopic aspiration biopsy showed proliferation of KIT-positive spindle-shaped heterotypic cells. GIST was diagnosed, and an exon 11 KIT mutation was found. Because of the exon 11 mutation, neoadjuvant IM was started at 400 mg/day and then eventually maintained at 300 mg/day for 10 months. Regular CT examinations showed gradual tumor shrinkage. At surgery, a tumor with strong extramural growth was found on the outer side of the duodenum that invaded the retroperitoneum. The tumor was excised as a mass, and the duodenum was resected partially. There has been no recurrence at 9 years postoperatively. Evaluating KIT exon mutations and predicting the effectiveness of NAC appear useful for determining the treatment policy for advanced GISTs.

A rare case of small bowel leiomyosarcoma presenting with acute gastro-intestinal bleeding

A 62-year-old Turkish female was admitted to our hospital with acute, progressive melena. Gastroscopy and colonoscopy could not reveal the cause of the melena. Subsequent CT angiography demonstrated a large, exophytic mass in the ileocecal junction as a source of the haemorrhage, leading to urgent laparotomy and resection. Histopathology revealed a low grade leiomyosarcoma (LMS) and confirmatory immunological staining. Primary LMS of the small bowel is an extremely rare gastrointestinal (GI) malignancy. Presentation with acute GI bleeding is even more exceptional, since LMS is a mainly intramural, exophytic tumour of the bowel wall. Immunohistochemistry plays a crucial role in differentiating LMS from GI stromal tumour. The work up of occult small bowel neoplasms currently consists of MRI enterography or enteroclysis and wireless capsule endoscopy. Treatment is surgical resection. This case highlights the non-specific imaging features of ileal LMS and highlights the management of acute GI bleed.

A Bleeding Duodenal GIST Masquerading as Refractory Peptic Ulcer Disease

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract; however, the occurrence of a GIST in the duodenum is rare. Our case demonstrates the importance of considering GIST in the evaluation of refractory duodenal ulcers, as well as the utilization of endoscopic ultrasound in the evaluation of these lesions.

Small Bowel Neoplasms and Polyps

The small intestine is a relatively privileged organ that only rarely develops malignant or even benign tumors. Given this rarity, the relative inaccessibility of the organ during routine endoscopic procedures, and the typical absence or nonspecific nature of clinical manifestations, these tumors often go undiagnosed. Treatment and prognosis are tailored to each histological subtype of tumor. This chapter will discuss the epidemiology, presentation, diagnostics, and management for the most common small bowel tumors, and will highlight the importance of recognizing patients at higher risk of small bowel neoplasia.

Recurrent fusion of the genes FN1 and ALK in gastrointestinal leiomyomas

Leiomyomas of the gastrointestinal tract are mostly found in the esophagus, stomach, and colon. Genetic information about them is very limited and no fusion genes have been described. We present herein cytogenetic and molecular genetic analyses of two gastrointestinal leiomyomas found in the esophagus and small intestine. The esophageal leiomyoma had the karyotype 45,Y,der(X)t(X;6)(p22;p21),inv(2)(p23q35),add(6)(p21),-11[cp6]/46,XY[7]. The intestinal leiomyoma karyotype was 46,X,add(X)(q2?),der(2)add(2)(p23)add(2)(q33),add(4)(p14),add(14)(q22)[10]/47,XX,+12[2]/46,XX[1]. RNA-sequencing detected FN1-ALK fusion transcripts in both tumors. RT-PCR together with Sanger sequencing verified the presence of the FN1-ALK fusion transcripts. Fluorescence in situ hybridization using an ALK breakapart probe further confirmed the rearrangement of the ALK gene. Immunohistochemical investigation of ALK in the leiomyoma of the small intestine revealed positivity with strong granular cytoplasmatic staining in the tumor cells. This is the first ever ALK fusion reported in gastrointestinal leiomyomas. Our results are of potential clinical importance because crizotinib, a selective ALK inhibitor, has demonstrated effect in patients whose tumors harbor ALK rearrangements. Thus, ALK emerges as a possible therapeutic target in patients whose tumors, including gastrointestinal leiomyomas, carry ALK fusions.

Surgical Strategy and Outcomes in Duodenal Gastrointestinal Stromal Tumor

BACKGROUND

The surgical management of duodenal gastrointestinal stromal tumors (DGIST) is poorly characterized. Limited resection may be technically feasible and oncologically safe, but anatomic considerations may compromise the resection margins due to the proximity of critical structures, thereby necessitating more extensive resections such as pancreaticoduodenectomy.

METHODS

Patients undergoing surgery for DGIST at two institutions from 1994 to 2014 were identified. Clinicopathologic and survival data were analyzed to compare outcomes in patients treated with limited or radical resection.

RESULTS

Sixty patients underwent surgery for DGIST. Pancreaticoduodenectomy was performed in 38 % while the rest underwent limited resections. The most common type of limited resection was wedge resection and primary closure (49 %) followed by segmental resection with an end-to-end or side-to-side duodenojejunostomy (27 %). The pancreaticoduodenectomy group tended to have larger tumors with the majority located in D2/3 (87 %) and at the mesenteric border (91 %). The pancreaticoduodenectomy group also had significantly greater intraoperative blood loss, longer operative time, longer hospital stay, and higher 90-day morbidity and readmission rates. The 5-year relapse-free survival, recurrence-free survival, and overall survival for the pancreaticoduodenectomy versus limited resection were 81 versus 56 % (p = 0.05), 64 versus 53 % (p = 0.5), and 76 versus 72 % (p = 0.6), respectively. A surgical algorithm based on the location and size of the tumor is proposed.

CONCLUSIONS

Limited resection of DGIST is safe, but may be associated with lower 5-year relapse-free survival. Pancreaticoduodenectomy is recommended for selected patients with DGIST when an R0 resection cannot be performed without removing the ampulla or part of the pancreas.

Combined Therapy of Gastrointestinal Stromal Tumors

Radical surgery is the mainstay of therapy for primary resectable, localized gastrointestinal stromal tumors (GIST). Nevertheless, approximately 40% to 50% of patients with potentially curative resections develop recurrent or metastatic disease. The introduction of imatinib mesylate has revolutionized the therapy of advanced (inoperable and/or metastatic) GIST and has become the standard of care in treatment of patients with advanced GIST. This article discusses the proper selection of candidates for adjuvant and neoadjuvant treatment in locally advanced GIST, exploring the available evidence behind the combination of preoperative imatinib and surgery.

KIT-positive Gastrointestinal Stromal Tumor in a 22-year-old Male Chimpanzee (Pan troglodites)

Gastrointestinal stromal tumors (GIST), KIT-positive and KIT signaling driven or platelet-derived growth factor receptor α (PDGFRA) signaling driven mesenchymal tumors, are poorly known in nonhuman primates. Availability of KIT- and PDGFRA-inhibitor drug imatinib mesylate has greatly raised the interest for these tumors. At necropsy of a 22-year-old male chimpanzee, a round, firm 2-cm intramural tumor was incidentally found in the midbody of the stomach and diagnosed as a GIST. Histologically, the mass was composed of spindle to polygonal epithelioid cells arranged in short to intermediate-length, interlacing streams, bundles, and nodular whorls often separated by hyalinized eosinophilic matrix. The mitotic rate was a maximum 1/50 high-power field. Immunohistochemically, the tumor cells were diffusely positive for KIT and CD34, focally positive for α-smooth muscle actin, and negative for muscle specific actin, desmin, S-100 protein, synaptophy-sin, and glial fibrillary acidic protein. Because the majority of human GISTs have gain-of-function KIT or PDGFRA mutations, genomic sequences of KIT exons 9, 11, 13, and 17 and PDGFRA exons 12 and 18 from this chimpanzee GIST were polymerase chain reaction amplified and sequenced. However, no mutation was identified in the analyzed “mutational hot spots.” This study is the first extensive histomorphologic, immunohistochemical, and molecular genetic analysis of a chimpanzee GIST. More cases of nonhuman primate GISTs should be analyzed to discover the clinicopathologic spectrum of GISTs in these species.

Gastrointestinal Stromal Tumors: A Clinicopathologic and Risk Stratification Study of 255 Cases from Pakistan and Review of Literature

PURPOSE

To describe the clinicopathological features of gastrointestinal stromal tumors (GIST) diagnosed in our section and to perform risk stratification of our cases by assigning them to specific risk categories and groups for disease progression based on proposals by Fletcher et al and Miettinen and Lasota.

MATERIALS AND RESULTS

We retrieved 255 cases of GIST diagnosed between 2003 and 2014. Over 59% were male. The age range was 16 to 83 years with a mean of 51 years. Over 70% occurred between 40 and 70 years of age. Average diameter of tumors was 10 cms. The stomach was the most common site accounting for about 40%. EGISTs constituted about 16%. On histologic examination, spindle cell morphology was seen in almost of 85% cases. CD117 was the most useful immunohistochemical antibody, positive in 98%. Risk stratification was possible for 220 cases. Based on Fletcher's consensus proposal, 62.3 gastric, 81.8% duodenal, 68% small intestinal, 72% colorectal and 89% EGISTs were assigned to the high risk category; while based on Miettinen and Lasota's algorithm, about 48% gastric, 100% duodenal, 76% small intestinal, 100% colorectal and 100% EGISTs in our study were associated with high risk for disease progression, tumor metastasis and tumor related death. Follow up was available in 95 patients; 26 were dead and 69 alive at follow up. Most of the patients who died had high risk disease and on average death occurred just a few months to a maximum of one to two years after initial surgical resection.

CONCLUSIONS

Epidemiological and morphologic findings in our study were similar to international published data. The majority of cases in our study belonged to the high risk category.

Local resection for duodenal gastrointestinal stromal tumors

BACKGROUND

Duodenal gastrointestinal tumors (GIST) present infrequently, and surgical resection with negative margins remains the mainstay of therapy; however, given the lack of lymphatic and submucosal spread and anatomic location near the bile duct and pancreas, the optimal approach for resection is unknown. Options include local resection (LR), segmental resection, and pancreaticoduodenectomy (PD).

METHODS

All cases of gastrointestinal stromal tumors originating from the duodenum from 2000 to 2015 were identified from administrative databases. Clinical and pathologic information was abstracted from the medical record and compared between patients who received LR vs PD. The chi-square with Fisher's exact test was used to detect differences between groups.

RESULTS

Fifteen patients met the inclusion criteria, of which 7 had an LR and 8 had a PD. The second portion of the duodenum was the most common origin of GIST in the PD group, whereas the third portion was most common in the LR group. Patients who underwent LR tended to be younger, but there was no difference in tumor size, mitotic rate, margin positivity, readmission rate, or recurrence. PD was associated with more complications, higher blood loss, and longer length of stay.

CONCLUSIONS

Local resection is a reasonable option for resection of duodenal GIST and should be routinely considered if technically feasible.

Gastrointestinal (GI) leiomyosarcoma (LMS) case series and review on diagnosis, management, and prognosis

This review of 76 gastrointestinal (GI) leiomyosarcoma (LMS) cases that include 11 cases from the American University of Beirut Medical Center represents, to our knowledge, the largest number of combined GI LMS cases reported. The age range of GI LMS is variable, and the presentation is non-specific, making pathological diagnosis essential. LMSs usually lack CD117 and CD 34 mutations and are usually positive for smooth muscle cell markers. The review highlights surgery as the mainstay of treatment with negative margins attained most of the times. Adjuvant chemotherapy is used in around 7-27 % of the cases mainly for small intestinal and colorectal LMS. The relatively small number of patients is a limitation on outcome analysis. However, LMS has a risk of recurrence reaching 39-80 % and secondary metastasis reaching 55-71 % in small intestinal and colorectal cases. In light of the high frequency of recurrence and metastasis, enrolling patients in clinical randomized trials to investigate the role of chemotherapy, radiation therapy, and targeted therapy is required for better control of this rare aggressive GI tumor.

Limited resections for duodenal gastrointestinal stromal tumors and their oncologic outcomes

PURPOSE

Limited resection is considered a treatment option for duodenal gastrointestinal stromal tumors (GISTs) whenever technically feasible, but the optimal technique for this is still not well defined. We present the various types of limited resections for duodenal GISTs and analyze their postoperative outcomes.

METHODS

The subjects of this retrospective clinicopathologic analysis were 21 patients who underwent limited resections for duodenal GIST between May, 2001 and June, 2014. The median follow-up period was 52 months (range 5-125 months).

RESULTS

The patients comprised 12 men and 9 women, with a median age of 59 years (range 45-75 years), all of whom were treated by various forms of limited resection with clear margins. There were ten wedge resections with primary closure (eight open/two laparoscopic), two wedge resections with Roux-en Y duodenojejunostomy, three segmental duodenectomies with end-to-end duodenoduodenostomy, and six segmental duodenectomies with end-to-end duodenojejunostomy. Hepatic metastasis was found 27 months after surgery in one patient, who was given imatinib mesylate for 17 months to slow disease progression. The other 20 patients were alive and recurrence free at the time of writing.

CONCLUSION

Excellent recurrence-free survival was achieved after limited resections, supporting the consideration of various methods of limited resection as the treatment of choice for duodenal GISTs.

Expression of cyclooxygenase 2 in gastrointestinal stromal tumors

AIM: To investigate the correlation of cyclooxygenase 2 (COX2) protein and mRNA expression with clinicopathological characteristics and prognosis in gastrointestinal stromal tumors (GISTs).

METHODS: EnVision technique was used to detect COX2 protein expression in GISTs and in situ hybridization method was used to detect COX2 mRNA expression. The patients were followed for prognosis evaluation.

RESULTS: Of 74 cases of GISTs, positive expression of COX2 protein was observed in 62 (83.8%) cases and positive expression of COX2 mRNA was observed in 58 (78.4%). COX2 protein and mRNA expression between different risk groups was statistically significant (P < 0.05), with the highest positive expression in the high risk group. COX2 protein and mRNA expression had no significant correlation with gender, age, lesion location, histological type, or metastasis (P > 0.05). A total of 38 (51.4%) patients were followed; of 24 patients with strongly positive expression of COX2 protein, 5 had metastases and 2 died. No recurrence, metastasis or death was observed in cases with negative, weakly positive or moderately positive expression. Of 17 cases showing strongly positive expression of COX2 mRNA, 3 had metastases and 2 died. No recurrence, metastasis or death was found in all 6 cases with negative expression of COX2 mRNA. Metastasis was observed in a case with weekly positive expression and a case with moderately positive expression, with no recurrence or death.

CONCLUSION: Upregulation of COX2 protein and mRNA expression in GISTs suggests that COX2 is a possible indicator for GISTs risk stratification and might affect prognosis.

Robot-assisted resection of gastrointestinal stromal tumors (GIST): a single center case series and literature review

BACKGROUND

Robotic techniques are claimed to be an alternative to laparoscopic and open approaches for gastrointestinal stromal tumors (GIST) treatment. Our aim is to present our single center experience and a literature review.

MATERIALS AND METHODS

From June 2012 to August 2014, six patients with preoperative diagnosis of GIST were treated by robotic surgery at Sanchinarro University Hospital.

RESULTS

Two GIST tumors were localized in the second part of the duodenum, one in the first portion, two in the gastricantrum and another in the angular notch. Surgical procedures performed were two subtotal gastrectomies, one gastric wedge resection and three duodenal enucleations. None of the interventions needed conversion to open surgery. Mean operative time was 245 min (150-540). Mean hospital stay was 10.5 days (6-24). All lesions had microscopically negative resection margins. Mean follow-up was 24 months (8-33) with a disease-free survival rate of 100%.

CONCLUSIONS

A robotic approach for GIST tumors is a safe and feasible procedure with a well-accepted oncological surgical result. Copyright © 2015 John Wiley & Sons, Ltd.

Duodenal gastrointestinal stromal tumors: clinicopathological characteristics, surgery, and long-term outcome

Background

Duodenal gastrointestinal stromal tumors (DGIST) are rare, and data on their management is limited. We here report the clinicopathological characteristics, different surgical treatments, and long-term prognosis of DGIST.

Methods

Data of 74 consecutive patients with DGIST in a single institution from June 2000 to June 2014 were retrospectively analyzed. The overall survival (OS) and recurrence/metastasis-free survival rates of 74 cases were calculated using Kaplan–Meier method.

Results

Out of 74 cases, 42 cases were female (56.76 %) and 32 cases (43.24 %) were male. Approximately 22.97, 47.30, 16.22, and 13.51 % of the tumors originated in the first to fourth portion of the duodenum, respectively, with a tumor size of 5.08 ± 2.90 cm. Patients presented with gastrointestinal bleeding (n = 37, 50.00 %), abdominal pain (n = 25, 33.78 %), mass (n = 5, 6.76 %), and others (n = 7, 9.76 %). A total of 18 patients (24.3 %) underwent wedge resection (WR); 39 patients (52.7 %) underwent segmental resection (SR); and 17 cases (23 %) underwent pancreaticoduodenectomy (PD). The median follow-up was 56 months (1–159 months); 19 patients (25.68 %) experienced tumor recurrence or metastasis, and 14 cases (18.92 %) died. The 1-, 3-, and 5-year recurrence/metastasis-free survival rates were 93.9, 73.7, and 69 %, respectively. The 1-, 3- and 5-year OS were 100, 92.5, and 86 %, respectively. The recurrence/metastasis-free survival rate in the PD group within 5 years was lower than that in the WR group (P = 0.047), but was not different from that in the SR group (P = 0.060). No statistically significant difference was found among the three operation types (P = 0.294).

Conclusions

DGIST patients have favorable prognosis after complete tumor removal, and surgical procedures should be determined by the DGIST tumor location and size.

Survival After Resection of Gastrointestinal Stromal Tumor and Sarcoma Liver Metastases in 146 Patients

BACKGROUND

We investigated outcomes by primary tumor type in patients who underwent resection of liver metastases from gastrointestinal stromal tumors (GIST), leiomyosarcomas, and other sarcomas.

METHOD

Our institutional liver database was used to identify patients who underwent resection from 1998 through 2013. Histopathological, clinical, and survival data were analyzed.

RESULTS

One hundred forty-six patients underwent resection of liver metastases from GIST (n = 49), leiomyosarcomas (n = 47), or other sarcomas (n = 50). The 5-year overall survival (OS) rates in patients with GIST, leiomyosarcomas, and other sarcomas were 55.3, 48.4, and 44.9%, respectively, and the 10-year OS rates were 52.5, 9.2, and 23.0%, respectively. The 5-year recurrence-free survival (RFS) rate was better for GIST (35.7%; p = 0.003) than for leiomyosarcomas (3.4%) and other sarcomas (21.4%). Lung recurrence was more common for leiomyosarcomas (36% of patients; p < 0.0001) than for other sarcomas (12%) and GIST (2%). For GIST, the findings support a benefit of imatinib regarding the 5-year RFS rate compared to resection alone (47.1 vs. 9.5%; p = 0.013). For leiomyosarcoma, primary tumor location did not affect the 5-year RFS rate (intraabdominal 14.5%; other location 0%; p = 0.182).

CONCLUSION

Liver metastases from GIST, leiomyosarcomas, and other sarcomas should be assessed separately as their survival and recurrence patterns are different. This is especially important for GIST, for which imatinib is now available.

Primary leiomyosarcoma of the colon

Primary leiomyosarcomas of the gastrointestinal (GI) tract are extremely rare and highly aggressive neoplasms, and only a small number of true cases have been reported since the concept of GI stromal tumors was established. Here, we report a case of a primary leiomyosarcoma of the transverse colon. A 46-year-old Japanese male with a large mass in the right upper abdomen was admitted to our hospital. Computed tomography and magnetic resonance imaging revealed long segments of wall thickening of the transverse colon with large consecutive tumors measuring 12 cm in diameter. A projecting irregular mass with marked mucosal necrosis was found on colonoscopy. Pathological examination revealed a spindle cell tumor growing circumferentially and transmurally to replace the muscularis propria in the transverse colon. The spindle cells were positive for smooth muscle actin, and negative for KIT, CD34, DOG-1, and S-100 protein. The patient has shown repeat recurrence in spite of sufficient surgical excision being promptly performed.

Duodenal gastrointestinal stromal tumor: From clinicopathological features to surgical outcomes

Duodenal gastrointestinal tumors represent an extremely rare subset of stromal tumors arising from interstitial cells of Cajal. In the last 30 years the comprehension of the pathophysiology and natural history of this previously misunderstood clinical entity, in association with developments in endoscopy, imaging technology, and immunohistochemistry has resulted in novel diagnostic and treatment approaches. This is a comprehensive review of the current data of the literature on the various aspects of the diagnosis and treatment of these tumors. The duodenum is the less commonly involved site for these tumors in the digestive tract. Endoscopy and computed tomography can usually establish the diagnosis, confirmed by immunohistochemical staining and occasionally molecular genetic analysis. Endoscopic ultrasound with fine needle aspiration has been recently found to be the gold diagnostic standard with high sensitivity and specificity rates, diagnosing GIST in up to 80% of patients. Due to the complex anatomy of the pancreatico-duodenal region optimal therapeutic strategy of duodenal GISTs are challenging. Nevertheless surgical resection with microscopically clear resection margins seems to be the only potentially curative treatment for non-metastatic primary GISTs of the duodenum. Imatinib mesylate plays a key role in the management of GISTs both as neoadjuvant therapy and in patients with recurrent and metastatic disease. Meanwhile, the advances in the comprehension of the pathophysiology and natural history of this previously misunderstood clinical entity as well as the treatment of these tumors may render feasible, in the near future, the advent of newer and more effective treatment options.

Assessment of early response to imatinib 800 mg after 400 mg progression by 18F-fluorodeoxyglucose PET in patients with metastatic gastrointestinal stromal tumors

ABSTRACT 

Introduction: Imatinib is the standard first-line therapy for advanced gastrointestinal stromal tumor. 18F-fluorodeoxyglucose PET computed tomography (FDG PET/CT) shows a faster response than computed tomography in nonpretreated patients. Patients & methods: After disease progression on imatinib 400 mg, 16 patients were exposed to 800 mg. Tumor response was evaluated by FDG PET/CT on days 7 and 37. Primary objective was to correlate early metabolic response (EMR) with progression-free survival (PFS). Results: EMR by FDG PET/CT scan was not predictive of PFS. Median PFS in these patients was 3 months. Overall survival was influenced by gastric primary site (p = 0.05). Conclusion: The assessment of EMR by FDG PET/CT in patients with advanced gastrointestinal stromal tumor exposed to imatinib 800 mg was not predictive of PFS or overall survival.

A case of a gastrointestinal stromal tumor with skeinoid fibers of the sigmoid colon

An 80-year-old man was diagnosed with rectal cancer and underwent Hartmann's procedure. Although no tumors were identified during the preoperative examination, gross examination of the resected specimen incidentally revealed a submucosal tumor that was 9 mm in diameter at the oral side and located in the proximal stump of the specimen from the sigmoid colon. We suspected a concurrent gastrointestinal stromal tumor (GIST) and performed a histopathological examination. An L-shaped nodular lesion measuring 9 × 6 mm was histologically composed of a patternless proliferation of spindle cells intermingled with eosinophilic globules. Cellular atypia, prominent mitotic figures and necrotic foci were not observed in the nodule. The spindle cells were positive for CD34, CD117 and vimentin, but negative for CD56, smooth muscle actin and S-100 protein. MIB-1 positivity was estimated to be as low as approximately 1–2%. Electron microscopy showed a bundle of wool-like fibers with a periodicity of approximately 40 nm. We therefore considered the lesion to be a low-risk GIST with skeinoid fibers in the large intestine. Although numerous previous reports have reported skeinoid fibers in the stomach and small intestines, there have been only 9 cases (including the present case) of skeinoid fibers in the large intestine.

Gastrointestinal stromal tumor - an evolving concept

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract. The discovery that these tumors, formerly thought of smooth muscle origin, are indeed better characterized by specific activating mutation in genes coding for the receptor tyrosine kinases (RTKs) CKIT and PDGFRA and that these mutations are strongly predictive for the response to targeted therapy with RTK inhibitors has made GISTs the typical example of the integration of basic molecular knowledge in the daily clinical activity. The information on the mutational status of these tumors is essential to predict (and subsequently to plan) the therapy. As resistant cases are frequently wild type, other possible oncogenic events, defining other "entities," have been discovered (e.g., succinil dehydrogenase mutation/dysregulation, insuline growth factor expression, and mutations in the RAS-RAF-MAPK pathway). The classification of disease must nowadays rely on the integration of the clinico-morphological characteristics with the molecular data.

Neurofibromatosis type 1: a multidisciplinary approach to care

Neurofibromatosis type 1 is a relatively common inherited disorder. Patients have a high predisposition to develop both benign and malignant tumours. Although many manifestations of neurofibromatosis type 1 affect the nervous system, other organs and tissues can also be affected. Because of the varying features and clinical heterogeneity inherent to this disorder, patients can present to different medical and surgical specialists and, therefore, the association of clinical symptoms with neurofibromatosis type 1 might not be appreciated. Thus, for prompt diagnosis and to provide optimum care for patients with neurofibromatosis type 1, clinicians must be aware of the diverse clinical features of this disorder. We advocate a multidisciplinary approach to care, entailing a dedicated team of specialists throughout the lifetime of the patient. As our understanding of this disorder deepens through basic laboratory and clinical investigations, swift implementation of new effective treatments becomes feasible.

Conservative surgery vs. duodeneopancreatectomy in primary duodenal gastrointestinal stromal tumors (GIST): a retrospective review of 114 patients from the French sarcoma group (FSG)

BACKGROUND

Duodenal GISTs represent 3-5% of all GISTs with limited understanding of patient outcomes. We conducted a retrospective analysis of primary localized duodenal GISTs.

METHODS

Patients were identified via a survey from 16 FSG centers (n = 105), and a group of 9 patients enrolled in the BFR14 trial. Data were collected from the original database and patient files, in agreement with French legislation.

RESULTS

114 patients were included, with a median age of 57. Tumors originated mainly in D2 (33%), or D3 (24%), with a median size of 5 cm. 109 patients had resection of the primary tumor; with a Local Resection (LR, n = 82), a pancreaticoduodenectomy (PD, n = 23), and data were missing for 4 patients. Resections were R0 (n = 87, 79%), R1 (n = 8, 7%), R2 (n = 6). Tumor characteristics were: KIT+ (n = 104), CD34+ (n = 58). Miettinen risk was low (n = 43), and high (n = 52). Imatinib was administered preoperatively (n = 11) and post-operatively (n = 20). With a median follow-up of 36 months (2-250), 98 patients are alive, and 33 relapsed. The 5-year OS and EFS rates are 86.5% and 54.5%. EFS was similar for patients in the LR and the PD groups (P > 0.05). In multivariate analysis, ECOG PS, and CD34 expression are independent prognostic factors on OS. Miettinen risk and spindle cell type are independent predictive factors for relapse.

CONCLUSIONS

Patients with resected duodenal GIST have a reasonably favorable prognosis. This study favors a preservation of pancreas when there are no anatomical constraints. LR exhibit similar survival and smaller morbidity then PD.

Extra-gastrointestinal stromal tumor of the pancreas: case report and review of the literature

Primary extra-gastrointestinal stromal tumor (EGISTs) arising in the pancreas is extremely rare: only 20 cases have previously been reported in the English literature from 2000 to 2013. We reported a case of EGIST of the pancreas in a 69-year-old woman who presented with abdominal pain and with a solid, heterogeneously enhancing neoplasm in the uncinate process of the pancreas, revealed preoperatively by an abdominal computed tomography scan. A diagnosis of neuroendocrine tumor was suggested. Positron emission tomography with 68Ga-DOTATOC did not show pathological accumulation of the tracer in the pancreas. The patient underwent enucleation, under ultrasonic guidance, of the pancreatic tumor that emerged to the surface of the pancreas. Histopathology and immunohistochemical examination confirmed the final diagnosis of EGIST of the pancreas (CD117+), with one mitosis per 50 high-power fields. Although rarely, GIST can involve the pancreas as a primary site, and this tumor should be considered in the differential diagnosis of pancreatic neoplasms.

Tumors of the angle of Treitz: A single-center experience

AIM: To explore the feasibility and oncologic outcomes of segmental jejunal resection on the left side of the mesenteric vessels in patients with tumors of the angle of Treitz using data from a single center.

METHODS: Thirteen patients with tumors of the angle of Treitz who underwent surgery at our institution were prospectively followed. A segmental jejunal resection on the left side of the mesenteric vessels was performed in all patients. Formalin-fixed and paraffin-embedded tumor samples were examined. The primary end point of this analysis was disease-free survival.

RESULTS: In this study, there were 8 males and 5 females (mean age, 50.1 years; range, 36-74 years). The mean tumor size was 8.1 cm (range, 3.2-15 cm). Histologic examination showed 11 gastrointestinal stromal tumors (GISTs) and 2 adenocarcinomas. Five of the GIST patients presented with potential low risk, and 6 presented with intermediate and high risk, according to the National Institutes of Health criteria. One potentially high-risk patient showed tumor progression at 46 mo and died 52 mo after surgery. One patient with locally advanced adenocarcinoma received neoadjuvant chemotherapy and adjuvant radiotherapy, but the disease progressed, and the patient died 9 mo after surgery. One GIST patient without progression died 16 mo after surgery because of a postoperative intestinal obstruction. The median overall survival rate was 84.6 mo, and the median disease-free survival rate was 94.5 mo.

CONCLUSION: The overall survival of patients with tumors of the angle of Treitz was encouraging even when the tumor size was relatively large. A segmental resection on the left side of the mesenteric vessels is considered to be a reliable and curative option for tumors of the angle of Treitz.

Gastrointestinal stromal tumors: what do we know now?

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the GI tract, arising from the interstitial cells of Cajal, primarily in the stomach and small intestine. They manifest a wide range of morphologies, from spindle cell to epithelioid, but are immunopositive for KIT (CD117) and/or DOG1 in essentially all cases. Although most tumors are localized at presentation, up to half will recur in the abdomen or spread to the liver. The growth of most GISTs is driven by oncogenic mutations in either of two receptor tyrosine kinases: KIT (75% of cases) or PDGFRA (10%). Treatment with tyrosine kinase inhibitors (TKIs) such as imatinib, sunitinib, and regorafenib is effective in controlling unresectable disease; however, drug resistance caused by secondary KIT or PDGFRA mutations eventually develops in 90% of cases. Adjuvant therapy with imatinib is commonly used to reduce the likelihood of disease recurrence after primary surgery, and for this reason assessing the prognosis of newly resected tumors is one of the most important roles for pathologists. Approximately 15% of GISTs are negative for mutations in KIT and PDGFRA. Recent studies of these so-called wild-type GISTs have uncovered a number of other oncogenic drivers, including mutations in neurofibromatosis type I, RAS genes, BRAF, and subunits of the succinate dehydrogenase complex. Routine genotyping is strongly recommended for optimal management of GISTs, as the type and dose of TKI used for treatment is dependent on the mutation identified.

Diagnosis and treatment of duodenal gastrointestinal stromal tumors

Duodenal gastrointestinal stromal tumors are common primary tumors of the duodenum, which are regarded as a group of gastrointestinal stromal tumors in most studies. However, since the duodenum has a special anatomical position and is adjacent to important organs, the diagnosis and treatment of duodenal gastrointestinal stromal tumors have a certain particularity. This paper discusses the special aspects of the diagnosis and treatment of duodenal gastrointestinal stromal tumors, especially the selection of right means of operation based on the tumor condition and the use of effective targeted therapy to achieve good outcome.

Single-incision laparoscopic and endoscopic cooperative surgery for gastrointestinal stromal tumor arising from the duodenum

We report a case involving a minimally invasive single-incision laparoscopic and endoscopic cooperative local excision of a duodenal gastrointestinal stromal tumor. A 59-year-old man presented with a 35-mm lesion located in the second portion of the duodenum. A local resection was performed via single-incision laparoscopic and endoscopic cooperative surgery. Intraluminal endoscopic dissection of the duodenal mucosa and submucosa was performed circumferentially around the tumor. The resection was then completed by laparoscopic dissection of the seromuscular layer around the tumor. The tumor was retrieved laparoscopically. After confirming that the resection achieved clear surgical margins, we closed the duodenal wall with a laparoscopic stapling device. There were no postoperative complications, including stenosis. Single-incision laparoscopic and endoscopic cooperative surgery can be safely and effectively performed for a duodenal submucosal tumor.

MDCT of primary, locally recurrent, and metastatic duodenal gastrointestinal stromal tumours (GISTs): a single institution study of 25 patients with review of literature

AIM

To describe the multidetector computed tomography (MDCT) features of primary, locally recurrent, and metastatic duodenal gastrointestinal stromal tumours (GISTs).

MATERIALS AND METHODS

In this institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant, retrospective study, 25 patients [13 men, 12 women; mean age 56 years (34-74 years)] with histopathologically confirmed duodenal GISTs seen at Dana Farber Cancer Institute and Brigham and Women's Hospital from December 1999 to October 2009 were identified. The MDCT of primary tumours in six patients and follow-up imaging in all the 25 patients was reviewed by two radiologists in consensus. Electronic medical records were reviewed to document the clinical characteristics and management.

RESULTS

The mean size of the primary tumour was 3.7 cm (range 2.5-5.6 cm). Three of six primary tumours were in the second and third portions of the duodenum, one in the third portion, one in the third and fourth portions, and one in the fourth portion. Three of six of the tumours were exophytic, two were both exophytic and intraluminal, and one was intramural. The tumours were well-circumscribed, round or oval masses, with few lobulations, and were either homogeneously hyper-enhancing or heterogeneously isodense at MDCT. None of the tumours had necrosis, haemorrhage, calcification, or loco regional lymphadenopathy on imaging. Sixteen of 25 (64%) patients developed metastatic disease, the most common sites being liver (14/16; 87.5%) and peritoneum (5/16; 31%).

CONCLUSION

Duodenal GISTs are well-circumscribed, round or oval masses, and occur in the second through fourth portions of the duodenum, without lymphadenopathy or duodenal obstruction. Duodenal GISTS metastasize frequently to the liver and peritoneum.

Pancreas-sparing duodenectomy for gastrointestinal stromal tumor

BACKGROUND

Pancreas-sparing duodenectomy (PSD) is a promising alternative procedure to pancreaticoduodenectomy for the treatment of duodenal tumors with low-grade malignant behavior.

METHODS

Between March 2003 and September 2012, PSD was performed in 7 patients with a gastrointestinal stromal tumor (GIST) in the second (n = 5) or third (n = 2) portions of the duodenum. The short- and long-term outcomes of treatment were analyzed in all patients.

RESULTS

The median blood loss was 160 mL, and the median operative time was 315 minutes. No pancreatic leakage or perioperative mortality occurred. Surgical margins were negative in all cases. All patients were alive at the median follow-up time of 42 months after PSD. The recurrence-free 5-year survival rate was 53% in all patients. Hepatic metastases developed in 2 of the 5 patients with high- or intermediate-grade risks at the time of diagnosis. Hepatic resection was performed, and imatinib mesylate was administered in the 2 cases.

CONCLUSIONS

Good short- and long-term outcomes and surgical curability were observed in patients treated with PSD for duodenal GIST.

Histopathological and clinical characteristics of duodenal gastrointestinal stromal tumors as predictors of malignancy

Background

Although gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, they are very rare. This study evaluated clinical and histopathological characteristics of duodenal GISTs to identify factors useful in predicting prognosis for patients with these tumors.

Methods

A retrospective study was performed on 20 patients who had undergone surgery between 1987 and 2009 for duodenal GISTs. Clinical, histopathological, and immunohistochemical data were evaluated. Survival analyses were conducted using Kaplan-Meier estimates.

Results

In 12 patients (60%), duodenal GISTs were diagnosed incidentally. Eight cases (40%) were classified as high risk grade GISTs. Skeinoid fibers (SkF), which are eosinophilic globular hyaline deposits in the extracellular interstitium of the tumor, were found in 12 patients. Skeinoid fibers were not recognized in 8 cases, and these included 3 cases (37.5%) where tumors recurred after surgery and the patient died. Tumors without SkF were larger (81 ± 92 vs. 23 ± 8 mm, P < 0.001) and had a higher mitotic count (224.0 ± 336.6 vs. 0.0 ± 0.0 /50 high-power field, P < 0.001) than those with SkF. Survival time was shorter in patients with tumors lacking SkF (52.9 ± 50.7 vs. 108.9 ± 86.5 months, P = 0.019).

Conclusions

We have identified clinical and histopathological characteristics that were useful in predicting the prognosis of patients with duodenal GISTs. In this study, 60% of the tumors were found incidentally, SkF were not recognized in tumors from 40% of patients, and all cases of post-operative tumor recurrence and death occurred in this subgroup of patients.