Intra-abdominal Desmoid Tumors Research Articles

Identifying intra-abdominal desmoid type fibromatosis mimicking recurrence/metastasis of GISTs using FAPI PET/CT.

e23516 Background: Intra-abdominal desmoid tumor (IADT) can mimic the recurrence/metastases of gastrointestinal stromal tumors (GISTs). However, it is difficult to radiologically differentiate IADT and recurrence/metastases of GISTs. This study aims to investigate the value of 18F fibroblast activation protein inhibitor ( [18F]FAPI-42) PET/CT in identifying intra-abdominal desmoid type fibromatosis mimicking recurrence/metastases of GISTs by comparing it to [18F]FDG PET/CT. Methods: This study retrospectively included a total of 24 patients (12 patients with IADT and 12 patients with recurrent/metastatic GISTs). The differences in [18F]FAPI-42 PET/CT parameters (SUVmax-FAPI and SUVTLR-FAPI ), [18F]FDG PET/CT parameters (SUVmax-FDG and SUVTLR-FDG), SUVfapi/SUVfdg ratio of IADT and GISTs were compared. The difference in PET/CT parameters (SUVmax, SUVTLR) of IADT between FDG PET/CT and FAPI PET/CT were compared. Immunohistochemical verification was performed on IADT lesions of all 12 patients and expression profiles of GEO datasets were analyzed to validate the FAP expression of IADT. Results: Both [18F]FAPI-42 PET/CT parameters, SUVmax-FAPI [8.8 (2.0, 16.0) vs 1.9 (1.0, 6.0), P< 0.001]and SUVTLR-FAPI [7.3 (2.0, 15.8) vs 1.7 (0.5, 6.9), P< 0.001], of IADT was significantly higher than that of GISTs, while there was no statistically significant difference in [18F]FDG PET/CT parameters, SUVmax-FDG and SUVTLR-FDG, between this two group. The ratio (SUVfapi/SUVfdg) of IADT was significantly higher than that of GISTs [3.3 (1.5, 8.0) vs 0.5 (0.1, 3.9), P= 0.001]. The SUVmax and SUVTLR of FAPI PET/CT of IADT were significantly higher than that of FDG PET/CT [8.8 (2.0, 16.0) vs 2.5 (1.1, 6.2), P< 0.001; 7.3 (2.0, 15.8) vs 0.9 (0.4, 2.7), P< 0.001; respectively]. FAP expression was found to be expressed in all the examined tissues and highly expressed in most of them. GEO database analysis shows that the FAP gene expression in DT is significantly higher than that in GISTs. Conclusions: FAPI PET/CT is a promising method in differentiating IADT from recurrence/metastases of GISTs compared with FDG PET/CT since FAP expression in DT is significantly higher than that in GISTs.

Investigation of clinicopathological characteristics and prognosis of abdominal Desmoid tumors

BackgroundAbdominal desmoid tumors (DTs) are rare soft-tissue neoplasms known for their relatively high local recurrence rate. This study aims to elucidate the clinicopathological features and investigate prognostic factors related to abdominal DTs across various tumor locations.MethodsFrom January 2000 to January 2021, patients diagnosed with abdominal DTs who underwent complete resection at the Cancer Hospital, Chinese Academy of Medical Sciences, were included in this study. Thorough collection and review of clinicopathologic characteristics and follow-up data were performed. Prognostic factors, including age at presentation, sex, tumor location, size, and proximity to nerves or vasculature, were meticulously analyzed to assess their impact on recurrence-free survival.ResultsA cohort of 226 patients diagnosed with abdominal DTs was categorized into two groups based on tumor site: the abdominal wall group (n = 132) and the intra-abdominal cavity group (n = 94). Distinct clinicopathological features and prognoses were observed between abdominal wall DTs and intra-abdominal DTs. During a median follow-up of 60 months, 24 patients (10.2%) experienced local recurrence. Univariate and multivariate analyses identified intra-abdominal tumors, tumor size >10cm, and positive margins as independent risk factors associated with poor prognosis.ConclusionAbdominal wall DTs demonstrate different clinicopathological characteristics and better prognoses compared to intra-abdominal DTs. By achieving negative margins, patients with abdominal wall DTs can achieve favorable therapeutic outcomes and prognosis through curative resection.

Volume-based 18F-FDG PET/CT predicts prognosis and outcome of active surveillance for intra-abdominal desmoid tumor.

Desmoid tumor (DT) is a rare monoclonal, fibroblastic proliferation characterized by a variable and often unpredictable clinical course. Initial active surveillance is recommended by current guideline, and surgery is one of the main therapies for DT. Predicting the prognosis and outcome of active surveillance for intra-abdominal DT is pressing issue. The study included eighteen patients with intra-abdominal DT. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) were measured. We analyzed their relationship with the outcome of active surveillance, as well as clinical, prognostic, and pathological data. The MTV and TLG of recurrent DT were significantly higher than those of non-recurrent DT (P < 0.001 and P = 0.00, respectively). The ROC curve suggested that the appropriate cutoff values for distinguishing recurrent DT from non-recurrent DT were 760.8 for MTV (sensitivity = 1, specificity = 0.857 and AUC = 0.929), and 1318.4 for TLG (sensitivity = 1, specificity = 0.786, and AUC = 0.911). The cutoff values of MTV and TLG significantly correlated with PFS using the Kaplan-Meier method (P = 0.002 and P = 0.007, respectively). MTV and TLG could distinguish DTs with subsequent progression from stable ones (P = 0.004 and P = 0.004, respectively). The ROC curve suggested that the appropriate cutoff values for distinguishing DTs with subsequent progression from stable ones were 197.1 for MTV (sensitivity = 0.9, specificity = 1, and AUC = 0.900), and 445.45 for TLG (sensitivity = 0.9, specificity = 1, and AUC = 0.900). Volume-based 18F-FDG-PET can predict prognosis of intra-abdominal DT. MTV and TLG can predict the outcome of active surveillance for intra-abdominal DT. MTV and TLG can potentially be predictors of surgical risk and difficulty.

Intra-abdominal fibromatosis following laparoscopic surgery for sigmoid colon cancer: A case report

Introduction: Desmoid tumors, also known as aggressive fibromatosis, are rare, benign, non-inflammatory, and fibroblastic tumors. Characterized by their locally aggressive behavior and the potential for recurrence, these tumors do not metastasize. Intra-abdominal desmoid tumors comprise 8% of all desmoid tumors. Case Report: This paper presents a case of a 50-year-old male, highlighting the diagnostic challenge posed by the incidental discovery of an intra-abdominal mesenteric mass in a patient previously treated for stage I sigmoid colon cancer by laparoscopic proctocolectomy. Multidisciplinary consensus favored surgical intervention, successfully revealing and removing a benign desmoid-type fibromatosis. The occurrence of intra-abdominal desmoid tumors after laparoscopic surgery for colorectal cancer is exceptionally rare, underscoring the unique nature of this case. Conclusion: During post-operative follow-up for colon cancer, the discovery of an intra-abdominal mass is often initially regarded as a sign of cancer recurrence and metastasis. Radiologists and oncologists may not immediately consider alternative causes. The incidentally discovered desmoid-type fibromatosis emphasizes the necessity for vigilant monitoring and consideration of diverse pathologies during follow-up, especially in low-risk scenarios.

The Role of Colon in Isolated Intestinal Transplantation: Description of 4 Cases.

Intra-abdominal desmoid tumors are a rare and complex clinical problem. These tumors are locally invasive, and surgical ablation represents the mainstay of treatment. When localized at the root of the mesentery, their resection may require extensive excision of the intestine resulting in intestinal failure and life-long total parenteral nutrition. Intestinal transplantation, either autotransplantation or allotransplantation, has been used as a viable option to treat this group of patients. Herein, we describe a series of 4 patients with unresectable intra-abdominal desmoid tumor who underwent cadaveric isolated intestinal and ascending colon transplantation.

A Case of Intraabdominal Desmoid Tumor Requiring Differentiation from Regional Lymph Node Recurrence after Gastrectomy for Gastric Cancer

A Case of Intraabdominal Desmoid Tumor Requiring Differentiation from Regional Lymph Node Recurrence after Gastrectomy for Gastric Cancer

Mesenteric fibromatosis involving intestine mimicking a gastrointestinal stromal tumor

Mesenteric fibromatosis (MF) or intra-abdominal desmoid tumour is a rare proliferative disease affecting the mesentery. MF is a locally aggressive tumour that lacks metastatic potential, but the local recurrence is common. We report a case of 33-year-old female with chief complaints of mass in abdomen which was hard on palpation arising from the pelvis and extending up to the umbilicus. Magnetic resonance imaging (MRI) suggestive of soft tissue mass and exploration was planned. Intra-operatively a mass of 16×16×8 cm with attached ileum and caecum which was excised completely and sent for histopathological examination. Histopathology was suggestive of Mesenteric fibromatosis spindle cell type. Considering the rarity of this tumour and difficulties in diagnostic and therapeutic ambit, we believe it is justified to publish this case which came to our observation.

136: Intestinal Transplant in patients with multiple FAP complicated by intraabdominal desmoid tumor: A Case Series

136: Intestinal Transplant in patients with multiple FAP complicated by intraabdominal desmoid tumor: A Case Series

Famitinib for familial adenomatous polyposis-associated aggressive desmoid tumors: A single-center exploratory study.

10513 Background: Desmoid tumour (DT) is a common extra-intestinal manifestation of familial adenomatosis polyposis (FAP), with high risk of recurrence and became the second leading cause of FAP patients’ death. The treatment of FAP-associated DTs are limited. Famitinib is a orally bioavailable, tyrosine kinase inhibitor against VEGFR-2, PDGFR, c-kit, and FGFR, and has shown antitumor activity in these patients (pts). Methods: This is a prospective, single arm study of FAP pts with progressing DT per RECIST v1.1, treated with famitinib 20 mg QD since 11/2021. The primary endpoint was objective response rate (ORR), with secondary endpoints of safety, progression-free survival (PFS), and quality of life (EORTC QLQ C30). We also collected the FFPE slices of DTs to test both genetic and proteomic backgrounds of pts with different therapeutic results. Results: Between Nov 24, 2021 and Aug 8, 2022, 11 pts were enrolled and evaluated every 9 weeks. The median follow-up time was 9.4 m (6.6 to 14.9 m). The median age was 36 (28-53) and 45% were male. Nine pts were diagnosed with intra-abdominal (IA) tumors while two had extra-abdominal (EA) DTs. Eight had stage III-IV DTs with rapid growth and severe symptoms. 10 of them had history of intestinal resection. Two pts were treated with dacarbazine and epirubicin before enrollment, while one patient received radiotherapy before famitinib. Five pts achieved partial response (PR) and six achieved stable disease (SD), with a median time to response of 7.0 months. The ORR was 45.5% and the disease control rate (DCR) was 100%. The 6-month PFS rate was 91%. The ORR of pts with IA DTs was 55.6%. Of adverse events (AEs) with famitinib, 87% were grade 1/2, the most frequently reported being hypertension (73%), neutropenia (64%), bilirubinemia (55%) and proteinuria (36%). Mean global health status/QoL before and after 6 months’ treatment was 58.3 vs 75.8 ( P= 0.09). Of all 11 pts, germline APC mutations scattered from codon 457 to 1578, and five of them detected somatic APC mutations from codon 547 to 1896 in DTs. Correlative study analysis will be presented. Conclusions: Famitinib demonstrated promising efficacy and a favorable safety profile in FAP-associated aggressive DTs.

Recent Advances and Current Management for Desmoid Tumor Associated with Familial Adenomatous Polyposis.

For nearly half a century, desmoid tumor (DT) has been considered a major complication that occurs in approximately 10%-25% of familial adenomatous polyposis (FAP) patients. It is also the leading cause of death in patients undergoing colectomy. We believe that the mortality rate is improving due to the understanding of the natural history of DT and recent advances in medical treatment. The risk factors of DT development include trauma, having a distal germline APC variant, having a family history of DTs, and estrogens. In the era of minimally invasive surgery, several reports demonstrated no significant difference in both surgical approach (laparoscopic vs. open) and surgical procedure (ileal pouch-anal anastomosis vs. ileorectal anastomosis). Regarding the treatment of FAP-associated DT, rapidly proliferating and life-threatening intra-abdominal DT accounts for approximately 10% of FAP-associated DT; however, it has been shown that it can be controlled by identifying and introducing cytotoxic chemotherapy. Moreover, tyrosine kinase inhibitors and γ-secretases, which are used to treat sporadic DT, which is more frequent than FAP-associated DT, are expected to be effective. In the future, such treatment is expected to further reduce the mortality rate from DT associated with FAP. In addition to the conventional staging of intra-abdominal DT, the classification proposed in Japan was recently thought to be useful for the treatment strategy of FAP-associated DTs. In this review, we summarize the recent advances and current management for the FAP-associated DT, including recent data from Japan.

Intra-abdominal desmoid tumor: Clinical case and literature review

Intra-abdominal desmoid tumor: Clinical case and literature review

Intra-abdominal desmoid tumors in familial adenomatous polyposis: How much do clinical and surgical variables interfere with their development?

ObjectiveFamilial Adenomatous Polyposis is a complex hereditary disease that exposes the carrier to a great risk of Colorectal Cancer (CRC). After prophylactic surgery, intra-abdominal desmoid tumors are known to be one the most important cause of death. Therefore, recognition of increased-risk patients and modification of operative strategy may be crucial. AimThe objective of this study was to estimate the desmoid tumor risk in relation to various surgical and clinical variables. MethodsPatients who had undergone polyposis since 1958 were included in the study. After exclusion criteria were met, those who had developed desmoid tumors were selected to undergo further evaluation. ResultsThe study revealed that the risk of developing desmoid tumors was associated with various factors such as sex ratio, colectomy, and reoperations. On the other hand, the type of surgery, family history, and surgical approach did not affect the risk of developing desmoid tumors. The data collected from 146 polyposis patients revealed that 16% had desmoid polyps. The sex ratio was 7:1, and the median age at colectomy was 28.6 years. Family history, multiple abdominal operations, and reoperations were some of the characteristics that were common in desmoid patients. Conclusion: Recognition of clinical (female sex) and surgical (timing of surgery and previous reoperations) data as unfavorable variables associated with greater risk may be useful during the decision-making process.

The dilemma in management of desmoid tumour: A case report

IntroductionDesmoid tumours are rare benign tumours. The tumours may develop sporadically or they may be linked to familial adenomatous polyposis (FAP) in Gardner’s syndrome.AimThis article highlights a young lady with an intra-abdominal desmoid tumour that manifested as an acute abdomen and we discuss our management strategy.Case studyA 24-year-old lady with a known FAP who had undergone a panproctocolectomy with an ileal pouch-anal anastomosis and total thyroidectomy, later was complicated with acute abdomen for symptomatic desmoid tumour. Computed tomography of the abdomen showed a large intraperitoneal heterogenous mass with small bowel displacement and was confirmed by magnetic resonance imaging. An exploratory laparotomy and en-bloc resection of the tumour with an end ileostomy were performed.Results and discussionIntra-abdominal desmoid tumours usually present as a painless slow-growing mass, however, in severe form, it can cause bowel ischemia, intestinal obstruction, or deterioration of function in the ileoanal anastomosis, among post total colectomy. Surgery is indicated upfront in specific clinical scenarios namely complications (occlusion, perforation, or bleeding) or major cosmetic issues.ConclusionsDesmoid tumour, despite being benign, is challenging to manage due to its compressing nature. As a key point, the diagnosis of a desmoid tumour should be suspected and followed up closely in patients with a previous history of FAP in combination with extracolonic manifestation.

Management of unresectable and recurrent intra-abdominal desmoid tumors treated with ultrasound-guided high-intensity focused ultrasound: A retrospective single-center study.

To assess the efficacy and safety of ultrasound (US)-guided high-intensity focused ultrasound (HIFU) ablation for treatment of unresectable and recurrent intra-abdominal desmoid tumors. From June 2014 to March 2020, 15 patients with consecutive unresectable and recurrent diseases that pathologically proven to be intra-abdominal desmoid tumors had undergone the treatment of US-guided HIFU ablation. All patients underwent contrast-enhanced magnetic resonance imaging before and after HIFU treatment. Nonperfused volume ratio was used to evaluate the effect of HIFU therapy. Intraprocedural and postprocedural adverse effects and complications are recorded to assess the safety of the therapy. Outcome of HIFU ablation has been investigated through serial contrast-enhanced imaging examinations during follow up. Out of 15 patients 14 of them have successfully completed the whole therapy, 1 patient is ineffective and gives up further treatment. The mean nonperfused volume ratio is 71.1% (95% confidence interval, 3% to 88.2%). During a mean follow up of 29 months (range from 8 to 61 months), the mean tumor volume was reduced by 59% (95% confidence interval, +49% to −100%). No tumor spreads along the treated area in all patients except one. Complications have occurred in 5 patients (33.3%), including bowel rupture (1 case), intra-abdominal abscess (1 case), slight injury to the femoral nerve (1 case), and bone injury (2 cases), the bowel rupture patient underwent surgery; the others have been cured during the follow up. US-guided HIFU ablation is an effective treatment modality for patients suffered from unresectable and recurrent intra-abdominal desmoid tumors.

INTRA-ABDOMINAL DESMOID TUMOUR- A RARE CASE REPORT WITH REVIEW OF LITERATURE.

Introduction: Desmoid tumours (DTs) are benign, slowly growing deep seated monoclonal myo-fibroblastic neoplasms. It arises from musculoaponeurotic stromal elements. The incidence in the general population is 2-4 cases per million people per year. DTs are typically sporadic; and can occur anywhere in the body. A 30 year male patient presented with a giant intraabdominal DT is discussed here with review of available literature. DTs areDiscussion: benign, deep-seated slowly growing monoclonal myo-fibroblastic neoplasms arise from musculoaponeurotic stromal elements. Diagnosis may be confirmed with biopsy and immunohistochemistry. Preoperative assessment with MRI, CT with angiogram are imperative for definitive surgical resection. There are roles of chemotherapy and radiation therapy in management of primary and recurrent lesions. The surgical resection remains the mainstay of its management. Conclusions: The management of DT is challenging. Surgical resection is the cornerstone of its management. Chemotherapy and radiation therapy in management of primary and recurrent lesions may be considered.

Efficacy of liposomal doxorubicin in patients with intra- and extra-abdominal desmoid fibromatosis.

11581 Background: Desmoid tumors (DT) or aggressive fibromatosis are rare growths of fibroblastic connective tissue that can be locally aggressive but without metastatic potential. Most cases are sporadic, but 5-20% of cases are associated with Familial adenomatous polyposis (FAP). Despite numerous systemic options, optimal choice is unclear, and there is a paucity of studies comparing efficacy based on tumor site. Liposomal doxorubicin (LD) can be an appealing option for DT patients (pts) given its favorable schedule and toxicity profile. In this study, we compared outcomes in pts with intra-abdominal (IA) and extra-abdominal (EA) DT who received LD. Methods: We identified pts with DT who were treated with LD between 1/2010 - and 2/2022 at two sarcoma centers. Tumor and pt characteristics and outcomes were clinically (symptom improvement) and radiologically (RECIST 1.1) assessed. Results: 40 pts with DT treated with LD were identified; 58% female and 42% male. Pt characteristics and outcomes are summarized in Table 1. Primary tumor site was IA in 21 (53%) pts. FAP was present more commonly in pts with IA vs EA DT, 8/21 (43%) and 4/19 (21%), respectively. In the IA cohort, LD was given as first (15/21, 71%), second (10%) or third (19%) line therapy. LD was used more commonly as a later line in the EA cohort with 16%, 52%, 16%, and 16% receiving it in first, second, third, and fourth lines, respectively. 37 pts were evaluable for response. Response rate in the IA cohort treated in first-line was 50% (8 of 16) and 10 of 12 evaluable pts had symptomatic improvement. No first-line responses were seen in the EA cohort. As later lines of therapy, 7/12 pts had disease control in the second line, 6/8 pts in the third line, and 1/2 pts in the fourth line with LD in the IA cohort. 1 patient had fourth line response to LD in the EA cohort. Disease control rate with LD was 72.5% across all pts. Reasons for early discontinuation of LD included progression or lack of symptom improvement (20%), allergic reaction (12.5%), adverse effects (7.5%), or infection (2.5%). No acute or long-term cardiotoxicity was reported. 2 pts had no signs of recurrence or symptoms at follow-up, 33 pts were alive with symptomatic DT, 1 patient died from disease, and 3 were lost to follow-up. Conclusions: In our study, LD provided tumor response, disease control, and symptomatic improvement regardless of location or prior therapy, with responses most frequently seen in IA DT in first line setting. Further studies should include comparison of efficacy, adverse effects, and patient-reported outcomes while accounting for tumor location and line of therapy. [Table: see text]

Identification and inner relation between gastrointestinal stromal tumor and intra-abdominal desmoid tumor

Intra-abdominal desmoid tumor (IADT) and gastrointestinal stromal tumor (GIST) are both mesenchymal tumors mostly found in gastrointestinal tracts and easily misdiagnosed, which would directly damage the survival prognosis and quality of life of patients. With the advent of the era of precision medicine, the understanding of the above two diseases is more in-depth, and the requirements for accurate diagnosis and individualized precision treatment are more stringent. Moreover, there seems to be some internal relationship between IADT and GIST, and the lack of systematic research and discussion makes clinical decision-making and patient management easy to fall into traps and misunderstandings. Therefore, this paper reviews the clinical characteristics, pathogenesis and treatments of the two, and explore their differences and internal relations, so as to provide research and practical reference for promoting more precise and individualized diagnosis and treatment regimens.

Sporadic intra-abdominal desmoid tumor with a very unusual onset: two case reports

BackgroundIntra-abdominal desmoid tumors are rare soft tissue tumors that arise mainly in the mesentery and pelvis. Their etiology may include genetic mutations, estrogen-associated changes after childbirth, and mechanical factors such as a history of abdominal surgery. However, there are cases of intra-abdominal desmoid tumors that develop in the absence of such causes. Since they are rare, diagnosis is often difficult based on clinical findings. We encountered two cases of patients with sporadic intra-abdominal desmoid tumors with a very unusual onset and contrasting features.Case presentationThe first patient was a 51-year-old asian man who presented with sudden onset of abdominal pain. He was referred to our department because of a giant tumor detected on abdominal ultrasonography. Imaging revealed a 19-cm tumor with internal tumoral hemorrhage; however, no definitive diagnosis was made. Tumor resection was performed for diagnostic and therapeutic purposes. The second patient was a 41-year-old asian man, and right hydronephrosis was detected on abdominal ultrasonography during a periodic medical checkup. We diagnosed invasion of the primary mesenteric tumor into the right ureter using diagnostic imaging and performed ileocecal resection with partial right ureteral resection for a definitive diagnosis and therapeutic purposes. Although the tumors of both patients had developed from the ileal mesentery, the tumors were substantially different from each other based on their imaging findings, macroscopic morphology, and progression pattern. Meanwhile, they showed similar pathological characteristics. Both consisted of bundles of collagen fibrils of spindle-shaped fibroblasts with low cell atypia. Moreover, they were diagnosed as desmoid tumors using positive immunohistochemical staining for β-catenin.ConclusionsNeither patient had susceptibility factors for desmoid tumors, and to our knowledge, there have been very few reports to date of intra-abdominal desmoid tumors that were diagnosed because of acute abdominal pain caused by tumoral hemorrhage or asymptomatic obstructive uropathy. Furthermore, it is clinically interesting that the two patients showed contrasting progression patterns and imaging findings. Intra-abdominal desmoid tumors are rare and may present with various symptoms and findings similar to those observed in our patients. Diagnosis therefore requires experience and knowledge that is not bound by preconceptions.

An Unusual Cause of Recurrent Subepithelial Mass in the Stomach

Question: A 58-year-old woman presented with a subepithelial tumor, approximately 2 cm in size, incidentally detected in the posterior wall of upper body of the stomach during a screening endoscopy (Figure A). The sample from an endoscopic ultrasound-guided fine-needle biopsy revealed spindle-shaped cells arranged in a fascicular pattern. The spindle cells were immunopositive for c-Kit, cluster of differentiation 34, DOG-1, and smooth muscle actin. The patient was diagnosed with a gastrointestinal stromal tumor (GIST) and underwent laparoscopic wedge resection. The tumor was completely resected with clear margins. The maximal tumor size was 2.3 cm, and the mitotic count was 2 per 50 high-power fields; therefore, it was diagnosed as a GIST with a low risk of malignant potential. Follow-up abdominal computed tomography after 2 years showed a new low-density mass in the previous resection site (Figure B, arrow). Endoscopy showed no definite lesion at the resection site (Figure C), and endoscopic ultrasound revealed a 1.5-cm heterogeneous hypoechoic lesion originating from the muscularis propria (Figure D). Laparoscopic wedge resection was performed again for a definitive diagnosis and treatment. What is your diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Histopathologic examination of the resected specimen revealed sweeping fascicles of bland and uniform spindle cells with collagenous stroma and compressed, thin-walled vessels (Figure E). The spindle cells were immunonegative for c-Kit (Figure F), cluster of differentiation 34 (Figure G), DOG-1 (Figure H), and S-100 protein, and were immunopositive for smooth muscle actin (Figure I), which suggested the exclusion of GIST. Therefore, additional immunohistochemistry was performed for the differential diagnosis. The tumor cells were negative for anaplastic lymphoma kinase but positive for nuclear β-catenin (Figure J). Based on morphologic and immunohistochemical findings, a diagnosis of a desmoid tumor occurring at the previous resection site of the gastric GIST was made. No further treatment was provided because the tumor was completely resected. No signs of recurrence or metastasis were found during 12 months of follow-up. Desmoid tumors are rare mesenchymal tumors occurring in patients with risk factors, such as a previous history of abdominal surgery, familial adenomatous polyposis, or pregnancy, and they can be easily mistaken for GIST because both tumors show similar clinical presentation and morphology.1Murshid A.A. Al-Maghraby H.Q. Subsequent development of desmoid tumor after a resected gastrointestinal stromal tumor.Case Rep Pathol. 2018; 2018: 1082956Google Scholar The desmoid tumor and GIST are both microscopically characterized by spindle-cell proliferation, and the differential diagnosis of these two tumors is performed mainly by immunohistochemistry. Because desmoid tumors usually have activating mutations in β-catenin, abnormal nuclear positivity of β-catenin is seen in most desmoid tumors.2Lu Q. Wang K. Liu D. et al.Stomach desmoid tumor: a case report and review of the literature.Int J Clin Exp Pathol. 2017; 10: 10531-10538Google Scholar Surgical resection with a negative margin is currently the treatment of choice. When local recurrence occurs or complete surgical resection is not feasible, radiotherapy, chemotherapy, and other comprehensive therapies, such as estrogen receptor antagonists and nonsteroidal anti-inflammatory drugs, should be provided.2Lu Q. Wang K. Liu D. et al.Stomach desmoid tumor: a case report and review of the literature.Int J Clin Exp Pathol. 2017; 10: 10531-10538Google Scholar Owing to the rarity of gastric desmoid tumors, information about their prognosis is very limited. According to a review of the literature on gastric desmoid tumors, no recurrence was reported during follow-up assessments,2Lu Q. Wang K. Liu D. et al.Stomach desmoid tumor: a case report and review of the literature.Int J Clin Exp Pathol. 2017; 10: 10531-10538Google Scholar indicating a good prognosis. However, considering the local recurrence rate of 13% for intra-abdominal sporadic desmoid tumors,3Wilkinson M.J. Fitzgerald J.E. Thomas J.M. et al.Surgical resection for nonfamilial adenomatous polyposis-related intraabdominal fibromatosis.Br J Surg. 2012; 99: 706-713Google Scholar regular follow-up is mandatory.

Intra-abdominal fibroid lesion of colonic involvement

Fibroid is a benign lump of growth, occurring within or outside the uterus. It is a rarity for such growths to occur intra-abdominally. Such cases are of aggressive fibromatosis which are marked by the presence of desmoid tumours. It is most commonly seen in patients with a history of familial adenomatous polyposis (FAP) or past surgical procedures. As FAP has a wide fibroepithelial growth spectrum, the symptomatology and therefore the prognosis varies. Unpredictable clinical behaviour, varied location and non-specific presentation are the factors accounting to diagnostic difficulty. Therefore, misdiagnosing the disease is not uncommon. Here we report a case ofa26-year-old pregnant female presenting with lower abdominal pain and mass. Preoperative diagnosis was of uterine fibroids as per radiological evidence, but on exploration it turned out to be a large right colonic mass. The patient underwent right hemicolectomy. Histopathological reports confirmed morphological and immuno-histochemical features indicating fibromatosis. This fibromatous mass though intra-abdominal was not growing from the mesentery/mesocolon or the pelvis. It appeared to grow from the wall of the colon. This is a confirmatory presentation of true colonic wall fibromatosis which is deep and isolated form of intra-abdominal desmoid tumours. As this lesion was isolated in nature, the treatment of choice was surgical resection. It is essential to have a multi-disciplinary team approach in the management of such a patient. This improves the treatment and the prognostic outcomes. Keywords: Fibroid, Colon, Fibromatosis, Hemicolectomy, Desmoid Tumour