Inflammatory myofibroblastic tumor: comparison of clinicopathologic, histologic, and immunohistochemical features including ALK expression in atypical and aggressive cases

Incomplete Intestinal Obstruction Caused by a Rare Epithelioid Inflammatory Myofibroblastic Sarcoma of the Colon: A Case Report

We reported on 1 case of epithelioid inflammatory myofibroblastic sarcoma (EIMS) that occurred in the colon and resulted in an incomplete intestinal obstruction.A 65-year-old male patient presented with abdominal pain without any obvious predisposing cause. He reported a paroxysmal dull pain. Hematochezia occurred occasionally. The symptoms appeared repeatedly and became progressively more aggravated. The patient sought medical advice in our hospital, and his enteroscopy showed colon tumors and an incomplete colonic obstruction. The laboratory examination indicated mild anemia. Plain and enhanced computed tomography (CT) scans showed a large, dumbbell-shaped, soft-tissue mass of 4.1 cm × 9.3 cm in the curved lumen of the descending colon near the spleen. After enhancement, the lesion presented with progressive and uneven enhancement. The boundary between the lesion and parts of the left kidney and spleen was obscured. A small amount of exudation was observed around the lumen, and a slightly enlarged lymph node shadow was observed in the mesangial gap.After each preoperative examination was completed, the tumors invading the spleen and left kidney were excised. Based on the surgical specimen pathological histology and immunohistochemistry, epithelioid inflammatory myofibroblastic sarcoma was diagnosed. Tumor recurrence occurred a short time after excision.EIMS in the abdominal cavity could occur on the intestinal wall, occasionally manifesting as large masses that expand to the inside and the outside of the cavity. It needs to be distinguished from other tumors. Tumor recurrence can easily occur after surgery. Anaplasticlymphoma kinase (ALK) inhibitors are a potential alternative treatment option.

Shedding light on inflammatory pseudotumor in children: spotlight on inflammatory myofibroblastic tumor

Inflammatory pseudotumor is a generic term used to designate a heterogeneous group of inflammatory mass-forming lesions histologically characterized by myofibroblastic proliferation with chronic inflammatory infiltrate. Inflammatory pseudotumor is multifactorial in etiology and generally benign, but it is often mistaken for malignancy given its aggressive appearance. It can occur throughout the body and is seen in all age groups. Inflammatory pseudotumor has been described in the literature by many organ-specific names, resulting in confusion. Recently within this generic category of inflammatory pseudotumor, inflammatory myofibroblastic tumor has emerged as a distinct entity and is now recognized as a fibroblastic/myofibroblastic neoplasm with intermediate biological potential and occurring mostly in children. We present interesting pediatric cases of inflammatory myofibroblastic tumors given this entity's tendency to occur in children. Familiarity and knowledge of the imaging features of inflammatory pseudotumor can help in making an accurate diagnosis, thereby avoiding unnecessary radical surgery.

Inflammatory Myofibroblastic Tumor Arising in the Pancreatic Head: a Rare Case Report

Inflammatory myofibroblastic tumor (IMT) is a rare neoplastic lesion with tendency toward local aggressive behavior and recurrence. It is primarily a visceral and soft tissue tumor; however, involvement of pancreas is extremely unusual. A localization in the pancreas needs differentiation from other tumors and chronic pancreatitis. We report a case of inflammatory myofibroblastic tumor arising in pancreatic head in a 32-year-old female who underwent Whipple's procedure.

Coexistence of gastrointestinal stromal tumor and inflammatory myofibroblastic tumor of the stomach presenting as a collision tumor: first case report and literature review

Collision tumors of the stomach are rare. We report on a case of a collision tumor consisting of a gastrointestinal stromal tumor (GIST) and an inflammatory myofibroblastic tumor (IMT) of the stomach in a 16-year-old female. A polypoid mass located in the distal body of the stomach was observed on abdominal computed tomography. Laparoscopic wedge resection of the stomach and 4d lymph node biopsy was performed. On gross examination, a protruding submucosal mass, measuring 4 × 3.5 × 2.5 cm in size, was detected. Histological examination showed two distinct GIST and IMT component presenting a collision tumor. The small nodular area, composed of CD117-positive spindle cells, was typical of GIST, and the adjacent larger area, composed of myofibroblastic spindle cells with prominent chronic inflammatory cells infiltrate, mainly lymphocytes and plasma cells, had a characteristic appearance of IMT. The 4d lymph node showed metastatic inflammatory myofibroblastic tumor. To the best of our knowledge, this is the first case of a collision tumor consisting of a GIST and an IMT arising in the stomach.

Inflammatory Myofibroblastic Tumor of Genitourinary Tract Beyond Collecting System: A Rare Case Report With Literature Review

Inflammatory myofibroblastic tumor (IMT) rarely arises in genitourinary tract especially beyond collecting system, which determines the unspecific clinic symptoms and sometimes can mimic malignancy. Therefore, IMT's diagnosis may usually be a pitfall. This case report characterizes a 35-year-old woman with a history of lower quadrant lasting pain followed by fever. Furthermore, radiologic examinations revealed that there were 2 lesions located in left adrenal area and left renalis. Owing to the anatomic complexity, the surgical resection was not complete. The pathologic diagnosis of the lesions was IMT. Adjuvant nonsteroids anti-inflammatory drugs were administrated after the operation. The symptoms were controlled finally and no further growing lesion was observed during a 1-year follow-up.Inflammatory myofibroblastic tumor is rare in genitourinary tract beyond the collecting system. Diagnosis should be based on histopathology. Presently, the authors report this rare case with the aim to share the experience regarding differential diagnosis and therapy.

Omental mesenteric myxoid hamartoma, a subtype of inflammatory myofibroblastic tumor? Considerations based on the histopathological evaluation of four cases

Omental mesenteric myxoid hamartoma (OMH) is a distinctive myxoid lesion of infancy, characterized by a benign clinical behavior. In the current World Health Organization (WHO) classification of soft tissue tumors, it is considered as part of the morphologic spectrum of inflammatory myofibroblastic tumors (IMT), but this relationship with IMT is still subject to debate. Four lesions with histologic features of OMH occurring in newborns and toddlers are described and compared with classic, ALK-positive IMT. All OMH showed a peculiar dot-like immunostaining for ALK, which, in one of the cases, was cytogenetically found to be associated with an inversion of the ALK gene. While OMHs were positive for smooth muscle actin (SMA), desmin, WT1, podoplanin, and cytokeratins (CAM5.2 and AE1-3), IMT were consistently positive only for SMA (10 cases). ALK-1 displayed cytoplasmic staining in IMT and characteristic paranuclear dot-like staining in OMH.

Inflammatory myofibroblastic tumor of the lung indistinguishable from adenocarcinoma on imaging studies

We present the case of a right lung nodule discovered on routine chest x-ray in an asymptomatic 62-year-old man. CT revealed a spiculated nodule in segment 1 of the right upper lobe, 2.2 cm in diameter and without calcification. The nodule showed high focal FDG uptake (SUVmax, 17.8) on PET. Right upper lobectomy was performed under the diagnosis of adenocarcinoma; however, the histopathologic findings were of inflammatory myofibroblastic tumor.

Successful surgical management of a rare esophageal inflammatory myofibroblastic tumour: a case report

Inflammatory myofibroblastic tumour (IMT) is an uncommon mesenchymal tumour, which can occur anywhere in the body, rarely in esophagus. Mostly, the diagnosis is postoperative, after the hispathological evaluation of the specimen. There are no definite guidelines regarding the diagnosis and management. Here, we report a 60 year old lady presenting with dysphagia, diagnosed to have a submucosal esophageal tumor with Barium esophagogram and contrast enhanced computed tomography. She was managed successfully with surgical enucleation with the final histopathological diagnosis of IMT. Surgical excision is not only therapeutic but also diagnostic in such cases.

Polypoid laryngeal inflammatory myofibroblastic tumors: misleading lesions: description of six cases showing ALK overexpression

OBJECTIVES

Laryngeal inflammatory myofibroblastic tumors (IMTs) are rarely reported in the literature but may be underrecognized. To better characterize their features, we report a series of six cases.

METHODS

The clinicopathologic findings, including immunohistochemistry, fluorescence in situ hybridization (FISH) analysis, and follow-up, were evaluated and a review of the literature was performed.

RESULTS

These cases presented as small polypoid vocal cord or ventricular band lesions, with a more advanced mean age at diagnosis (49 years) than typically reported in other localizations. Apart from one secondary revision surgery, no complementary treatment and no recurrences were observed. Histologically, various morphologic features were seen. All tumors were spindle cell proliferations on a myxoid background with more or less atypia and significant inflammatory infiltrate. All six cases showed anaplastic lymphoma kinase (ALK) immunohistochemical expression. FISH rearrangement was present in four of six cases. Only two cases were initially diagnosed as IMT.

CONCLUSIONS

According to our series, laryngeal IMTs are easily misdiagnosed. They have a good prognosis, and ALK immunohistochemistry should be carried out to assess this diagnosis when spindle cell proliferations are observed in this localization.

Inflammatory myofibroblastic tumor of the pancreatic head - a case report of a 6 months old child and review of the literature

BACKGROUND

Inflammatory myofibroblastic tumors are rare in the pediatric population. Most common localizations were reported in the lungs. A localization in the pancreas needs differentiation from other tumors and chronic pancreatitis. Treatment is surgical resection, although there are reports of treatment with oral steroids and radiation therapy.

CASE REPORT

A 6-month-old child was treated due to a tumor in the head of the pancreas. On admission he was jaundiced with pruritus. US and MRI confirmed pancreatic tumor. Preoperative biopsy wasn't conclusive regarding the nature of the tumor. Duodenopancreatectomy was performed. Postoperative course was uneventful. Histologic examination confirmed the diagnosis of inflammatory myofibroblastic tumor. On follow up, he remained with no evidence of recurrence.

CONCLUSIONS

A literature review revealed 10 cases of pancreatic inflammatory myofibroblastic tumors in the pediatric age group. Our patient is the youngest reported. Despite major resection, there were no complications. However, management of this child might be possible with steroids, but conservative treatment might be insufficient, especially in aggressive forms of tumors.

Molecular characterization of inflammatory myofibroblastic tumors with frequent ALK and ROS1 gene fusions and rare novel RET rearrangement

Approximately 50% of conventional inflammatory myofibroblastic tumors (IMTs) harbor ALK gene rearrangement and overexpress ALK. Recently, gene fusions involving other kinases have been implicated in the pathogenesis of IMT, including ROS1 and in 1 patient PDGFRB. However, it remains uncertain whether the emerging genotypes correlate with clinicopathologic characteristics of IMT. In this study, we expand the molecular investigation of IMT in a large cohort of different clinical presentations and analyze for potential genotype-phenotype associations. Criteria for inclusion in the study were typical morphology and tissue availability for molecular studies. The lack of ALK immunoreactivity was not an excluding factor. As overlapping gene fusions involving actionable kinases are emerging in both IMT and lung cancer, we set out to evaluate abnormalities in ALK, ROS1, PDGFRB, NTRK1, and RET by fluorescence in situ hybridization. In addition, next-generation paired-end RNA sequencing and FusionSeq algorithm was applied in 4 cases, which identified EML4-ALK fusions in 2 cases. Of the 62 IMTs (25 children and 37 adults), 35 (56%) showed ALK gene rearrangement. Of note, EML4-ALK inversion was noted in 7 (20%) cases, seen mainly in the lung and soft tissue of young children including 2 lesions from newborns. There were 6 (10%) ROS1-rearranged IMTs, all except 1 presenting in children, mainly in the lung and intra-abdominally and showed a distinctive fascicular growth of spindle cells with long cell processes, often positive for ROS1 immunohistochemistry. Two of the cases showed TFG-ROS1 fusions. Interestingly, 1 adult IMT revealed a RET gene rearrangement, a previously unreported finding. Our results show that 42/62 (68%) IMTs are characterized by kinase fusions, offering a rationale for targeted therapeutic strategies. Interestingly, 90% of fusion-negative IMTs were seen in adults, whereas >90% of pediatric IMT showed gene rearrangements. EML4-ALK inversion and ROS1 fusions emerge as common fusion abnormalities in IMT, closely recapitulating the pattern seen in lung cancer.

Cytopathologic features of epithelioid inflammatory myofibroblastic sarcoma with correlation of histopathology, immunohistochemistry, and molecular cytogenetic analysis

BACKGROUND

Epithelioid inflammatory myofibroblastic sarcoma (E-IMS) is a recently established rare variant of inflammatory myofibroblastic tumor. It is characterized by a distinctive constellation of clinical, pathological, and molecular features, including a nearly exclusive intraabdominal location, strong male predilection, aggressive clinical course, predominance of epithelioid tumor cells, and Ran-binding protein 2 (RANBP2)-anaplastic lymphoma kinase (ALK) fusion in the majority of cases. To the authors' knowledge, the cytologic features of E-IMS have not been described to date.

METHODS

Cases of E-IMS that had corresponding cytology were searched. Six cytology samples (1 fine-needle aspiration sample, 2 imprint samples, and 3 effusion fluids) containing tumor cells were identified in 5 patients with E-IMS.

RESULTS

The cytomorphology included large monotonous epithelioid cells arranged in loose aggregates or singly, with admixed myxoid stroma, and an inflammatory background rich in neutrophils. The tumor cells had a large, round, eccentric nucleus with vesicular chromatin, prominent nucleoli, and moderate amounts of pale cytoplasm. Delicate thin-walled branching vessels traversing tumor aggregates was a prominent feature in a fine-needle aspiration sample. Immunohistochemically, ALK was positive in all 5 tumors, with a nuclear membranous staining pattern noted in 3 cases and a cytoplasmic pattern observed in the other 2 cases. ALK rearrangement was confirmed in all 5 tumors by molecular genetic studies.

CONCLUSIONS

The cytologic features of E-IMS recapitulate its histologic characteristics. E-IMS merits inclusion in the differential diagnosis of any intraabdominal, large epithelioid cell neoplasm. Confirmation of ALK rearrangement is advisable because patients may benefit from targeted therapies.

Primary Inflammatory Myofibroblastic Tumors of the Breast with Metastasis: Radiographic and Histopathologic Predictive Factors

Primary inflammatory myofibroblastic tumors (IMTs) of the breast are uncommon and metastasis of IMTs is extremely rare. To date, the natural course of this disease is not fully understood. Although patients with IMTs should undergo regular follow-up after complete surgical resection of the tumor, the appropriate interval and method of follow-up are unclear. We report the case of a patient with an IMT of the breast that metastasized 2 years after complete surgical resection. This unusual case emphasizes the importance of preoperative examinations to determine whether the IMT has atypical features that should guide the interval and method of follow-up.

Abdominopelvic inflammatory myofibroblastic tumor that metastasized to the vertebrae and liver: A case report and review of the literature

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Inflammatory myofibroblastic tumor (IMT) tends to locally recur but rarely metastasizes.

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IMT tends to locally recur but rarely metastasizes.

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IMTs that do not express anaplastic lymphoma kinase (ALK) have worse prognosis.

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Current trials for ALK targeted therapies show promise in treating this neoplasm.

Expression of ROS1 predicts ROS1 gene rearrangement in inflammatory myofibroblastic tumors

Inflammatory myofibroblastic tumor is a distinctive, rarely metastasizing mesenchymal neoplasm composed of fascicles of spindle cells with a prominent inflammatory infiltrate. Roughly 50% of inflammatory myofibroblastic tumors harbor ALK receptor tyrosine kinase gene rearrangements. Such tumors are usually positive for ALK by immunohistochemistry. The molecular pathogenesis of ALK-negative inflammatory myofibroblastic tumors is largely unknown. A recent study identified rearrangements of ROS1 (another tyrosine kinase receptor) in a subset of ALK-negative inflammatory myofibroblastic tumors. Immunohistochemistry for ROS1 has been shown to correlate with ROS1 rearrangement in lung adenocarcinomas. The purpose of this study was to determine whether immunohistochemistry for ROS1 could predict ROS1 rearrangement in inflammatory myofibroblastic tumor. In total, 30 inflammatory myofibroblastic tumors were evaluated, including 21 ALK-positive tumors (10 confirmed to harbor ALK rearrangements, with TPM3, CLTC, RANPB2, and FN1 fusion partners) and 9 ALK-negative tumors (including 2 known to harbor ROS1 rearrangements). Immunohistochemistry was performed on whole tissue sections following pressure cooker antigen retrieval using a rabbit anti-ROS1 monoclonal antibody. The results were scored as 'positive' or 'negative,' and the pattern of staining was recorded. Three ALK-negative inflammatory myofibroblastic tumors (including both tumors with known ROS1 rearrangements) showed immunoreactivity for ROS1, whereas all ALK-positive inflammatory myofibroblastic tumors were negative for ROS1. One ROS1-positive inflammatory myofibroblastic tumor (with YWHAE-ROS1 fusion) showed strong, diffuse cytoplasmic and nuclear staining; one case (with TFG-ROS1 fusion) showed weak, diffuse and dot-like cytoplasmic staining; and one case (fusion partner unknown) showed moderate, diffuse and dot-like cytoplasmic staining. Expression of ROS1 correlates with ROS1 gene rearrangement in inflammatory myofibroblastic tumor. These findings suggest that immunohistochemistry for ROS1 may be useful to support the diagnosis of a subset of inflammatory myofibroblastic tumors and may select some clinically aggressive cases for targeted therapy directed against ROS1.

Neoadjuvant Crizotinib in Advanced Inflammatory Myofibroblastic Tumour with ALK Gene Rearrangement

Background

Inflammatory myofibroblastic tumours (IMTs) are rare sarcomas that were first described in the lung. They are composed of myofibroblastic mesenchymal spindle cells accompanied by an inflammatory infiltrate of plasma cells. Complete resection is the treatment of choice. There is currently no standard treatment for inoperable or recurrent disease. Expression of ALK protein triggered by ALK gene rearrangement at chromosome 2p23 has been found in 36%-60% of IMTs.

Case report

We report a rapid early response to crizotinib as neoadjuvant therapy, enabling surgical excision of a large ALK(-translocated IMT, which resulted in complete disease clearance. To the best of our knowledge, this is the first case in the literature of a patient with IMT in whom crizotinib was used successfully in the neoadjuvant or curative setting.

Assessment of the potential diagnostic role of anaplastic lymphoma kinase for inflammatory myofibroblastic tumours: a meta-analysis

Objective

To assess the value of anaplastic lymphoma kinase for the diagnosis of inflammatory myofibroblastic tumours using a comprehensive meta-analysis.

Methods

We searched the related literature using electronic databases and manual searches. Approximately 454 cases from several countries were included in this analysis. The quality of studies included was assessed by QUADAS (quality assessment of studies of diagnostic accuracy). The diagnostic odds ratio (DOR), positive likelihood ratio (PLR), negative likelihood ratio (NLR), sensitivity and specificity were calculated to assess the role of anaplastic lymphoma kinase in the diagnosis of inflammatory myofibroblastic tumours. The overall test performance was summarised by an SROC (summary receiver operating characteristic curve). The heterogeneity and publication bias were analysed using Meta-regression and Deeks' test. All data were analysed by Stata 12.0 software.

Results

Eight studies were included according to our inclusion criteria. The overall results for the specificity, sensitivity, PLR, NLR, DOR and area under the curve (AUC) were 0.99 (95% CI 0.82-1.00), 0.67 (95% CI 0.46-0.83), 0.67 (95% CI 0.46-0.83), 60.6 (95% CI 3.3-1112.4), 0.33 (95% CI 0.19-0.60), 181 (95% CI 9-3684) and 0.95 (95% CI 0.93-0.97), respectively, while the specificity, sensitivity, PLR, NLR, DOR and AUC for bladder IMTs were 0.99 (95% CI 0.67-1.00), 0.86 (95% CI 0.58-0.96), 95.6 (95% CI 2.0-4616.2), 0.14 (95% CI 0.04-0.50), 671 (95% CI 16-28913) and 0.99 (95% CI 0.97-0.99), respectively.

Conclusion

The present meta-analysis indicated that anaplastic lymphoma kinase plays a significant role in the differential diagnosis of inflammatory myofibroblastic tumours, particularly for inflammatory myofibroblastic tumours of the urinary bladder.

Inflammatory myofibroblastic tumor treated with laparoscopic proximal gastrectomy and double-tract anastomosis

Inflammatory myofibroblastic tumors (IMTs) of the stomach are extremely rare in adults, and their oncologic prognosis is not well understood. We present a 28-year-old man with a proximal gastric IMT. The patient visited the emergency department of Yeouido St. Mary's Hospital with syncope and hematemesis. Hemoglobin levels were <5.5 g/dl. Gastric fibroscopy showed a protruding mass 4×4 cm in size, with central ulceration on the posterior wall of the fundus and diffuse wall thickening throughout the cardia and anterior wall of the upper body. Endoscopic biopsy revealed indeterminate spindle cells, along with inflammation. Given the risk of rebleeding, an operation was performed despite the uncertain diagnosis. Because the mass was circumferential, laparoscopic proximal gastrectomy and double-tract anastomosis were performed to ensure a safe resection margin. The pathological diagnosis was consistent with an IMT originating from the stomach, although the tumor was negative for anaplastic lymphoma kinase gene mutation.

Inflammatory myofibroblastic tumor of the thigh: presentation of a rare case and review of the literature

Inflammatory myofibroblastic tumors are uncommon neoplasms; presentation of these tumors in the lower extremities is extremely rare. We present a case of a 47-year-old male with fever, fatigue, and a slow-growing thigh mass. The inflammatory markers were elevated and the MR images showed a well-defined intermuscular lesion with mild heterogeneous enhancement. The lesion was excised and histologic examination was consistent with an inflammatory myofibroblastic tumor. No adjuvant therapy was needed and the patient remained asymptomatic with no evidence of tumor recurrence during the 2 years of follow-up.

Inflammatory myofibroblastic tumor of the uterus: clinical and pathologic review of 10 cases including a subset with aggressive clinical course

Inflammatory myofibroblastic tumor is currently regarded as a neoplasm with intermediate biological potential and a wide anatomic distribution. Inflammatory myofibroblastic tumors of the female genital tract are rare, and to date reported cases behaved indolently. We describe, herein, 10 cases of uterine inflammatory myofibroblastic tumor, 3 of which had an aggressive clinical course. Subject age ranged from 29 to 73 years. Tumors were composed of spindle and epithelioid myofibroblastic cells admixed with lymphoplasmacytic infiltrates in a variably myxoid stroma. Two growth patterns, myxoid and fascicular (leiomyoma-like), were noted. All tumors were positive for ALK expression by immunohistochemistry, which was stronger in the myxoid areas. Smooth muscle marker and CD10 expression was variable in extent, but typically positive. Fluorescence in situ hybridization for ALK rearrangements was positive in both fascicular and myxoid areas in all 8 cases tested. Three subjects showed clinical evidence of tumor aggressiveness as defined by extrauterine spread, local recurrence, or distant metastasis. Aggressive tumors were larger, had a higher proportion of myxoid stroma, and higher mitotic activity than indolent tumors. Tumor cell necrosis was seen only in cases with adverse outcome. This is the first report to describe aggressive biological behavior in uterine inflammatory myofibroblastic tumor. This diagnosis is often underappreciated and merits inclusion in the differential diagnosis of myxoid mesenchymal lesions of the uterus, particularly because patients with an aggressive course may benefit from targeted therapy.

Inflammatory myofibroblastic tumor of the esophagus in childhood: a case report and a review of the literature

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal disease of low malignancy consisting of inflammatory cells inside a mesenchymal stroma comprising myofibroblasts. Biological behavior is variable, recurrence is uncommon, metastatic disease is rare. Treatment strategy is based on the status of low-grade malignant tumor. Radical surgery is considered to be the principal treatment modality, except if it requires a mutilating procedure. Only 6 cases of pediatric patients treated for IMT of the esophagus have been reported in English-language literature. Herein, a case of a 13-year-old boy with an IMT of the esophagus is presented.

Voluminous omental inflammatory myofibroblastic tumor in an elderly man: a case report and literature review

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm of intermediate biologic potential, with uncertain etiology. This tumor occurs primarily in the lung, but the tumor may affect any organ system. A 75-year-old male was evaluated for voluminous palpable high abdominal mass with continuous and moderately abdominal pain, associated with abdominal distension for the last two months. Abdominal computed tomography showed a large (32 × 29 × 15 cm) heterogeneously enhanced mass with well-defined margins. At surgery, the mass originated from the greater omentum was completely excised. Histologically the tumor was a mesenchymal neoplasm in smooth muscle differentiation and was characterized by spindle-cell proliferation with lymphocytes, plasma cells, and rare eosinophils. Immunohistochemically, the tumor cells were positive for vimentin and smooth muscle actin and negative for anaplastic lymphoma kinase. Complete surgical resection of IMTs remains the mainstay of treatment associated with a low rate of recurrence. Final diagnosis should be based on histopathological and immunohistochemical findings. Appropriate awareness should be exercised by surgeons to abdominal IMTs in combination with constitutional symptoms, abnormal hematologic findings, and radiological definition, to avoid misdiagnosed.

Contemporary diagnostics: sarcoma pathology update

Sarcoma diagnosis continues to evolve as new information is discovered. Certain tumors have been downgraded (dermal leiomyosarcoma) and an atypical category designed for others. Recently entities include myxoinflammatory fibroblastic sarcoma, myoepithelioma, and pseudomyogenic hemangioendothelioma. The terms malignant fibrous histiocytoma and hemangiopericytoma are outdated. New immunostains (STAT6, SOX10, ERG) add diagnostic specificity, and new risk assessment models are described for sarcomas where grading and staging has failed to provide adequate prognosis.

Anaplastic lymphoma kinase protein expression, genetic abnormalities, and phosphorylation in soft tissue tumors: Phosphorylation is associated with recurrent metastasis

Gene and protein abnormalities of anaplastic lymphoma kinase (ALK) play an important role in the pathogenesis of various cancers and serve as important therapeutic targets. We investigated ALK protein expression, phosphorylation, and genetic aberrations using fluorescence in situ hybridization (FISH) in 81 soft tissue tumor samples: inflammatory myofibroblastic tumor, n=1; alveolar soft part sarcoma, n=2; leiomyosarcoma, n=10; well-differentiated liposarcoma, n=7; pleomorphic liposarcoma, n=2; extraskeletal osteosarcoma, n=1; epithelioid sarcoma, n=1; synovial sarcoma, n=4; malignant peripheral nerve sheath tumor, n=4; undifferentiated pleomorphic sarcoma, n=19; rhabdomyosarcoma, n=6; myxofibrosarcoma, n=8; myxoid liposarcoma, n=11; fibrosarcoma, n=4; and desmoid-type fibromatosis, n=1. ALK protein expression, gene signal gain (without translocation), and phosphorylation were observed in 33/81 (40.7%), 55/81 (67.9%), and 30/81 (37.0%) tumor samples, respectively. ALK protein expression was statistically associated with phosphorylation, but not with gene signal gain. ALK phosphorylation-positive cases showed a statistically worse metastasis-free survival compared with phosphorylation-negative cases (P=0.0215). Particularly, metastasis of myxoid liposarcoma was associated with ALK phosphorylation (P=0.0019), but not with ALK protein expression or gene signal gain. However, the prognosis had no association with ALK protein expression, gene signal gain, or phosphorylation. ALK protein expression and phosphorylation play an important role in tumor biology and provide potential therapeutic targets for soft tissue tumors. Future research should focus on the oncogenic role and the efficacy of potential inhibitors of ALK.

Maxillary sinus inflammatory myofibroblastic tumors: a review and case report

An inflammatory myofibroblastic tumor (IMT) is an immunohistochemically diverse entity demonstrating neoplastic and nonneoplastic qualities. Although IMTs can arise in any area of the body, lesions arising in certain sites, namely, the nasal cavity, paranasal sinuses, and pterygopalatine fossa, demonstrate a heightened neoplastic and invasive potential. Despite case specific complete tumor regression and disease remission in response to pharmacotherapeutics, a subset of IMTs remain resistant to all forms of therapy. We present such a case, a 34-year-old female patient, with a highly resistant, maxillary sinus IMT. Her refractory, ALK-1 negative IMT has not responded well to novel therapies reported in current literature. This case suggests the role of zonal expressivity within a single lesion as a probable mechanism for its highly resistant nature and should promote determination of each IMT's cytogenetic profile to provide more effective targeted therapy. Paper includes a literature review of all maxillary sinus IMTs from 1985 to 2014 along with their immunohistochemical staining, treatments, and outcomes.

Inoperable inflammatory myofibroblastic tumour of the para-nasal sinuses and orbit with recurrence responding to methotrexate and prednisolone: a case report

BACKGROUND

Inflammatory myofibroblastic tumour is a rare neoplasm with a potential to behave in a malignant manner. It can occur anywhere in the body, however involvement of the head, especially the para-nasal sinuses is rare.

CASE PRESENTATION

A 33-year-old South Asian male presented with coryzal symptoms including a persistent cough with an asymmetrical swelling of the left side of the face. Imaging revealed a mass lesion involving the para-nasal sinuses eroding into the orbit. Histology and the clinical picture were compatible with inflammatory myofibroblastic tumour. As curative excision of the tumour was not feasible, medical management was offered. Despite early features of remission to glucocorticoids, tapering resulted in recurrence. Hence combination therapy with glucocorticoids and methotrexate was commenced with dramatic reduction of tumour burden and the patient has been in remission to date.

CONCLUSION

Inflammatory myofibroblastic tumour has the potential to behave in a malignant manner. Medical management with chemotherapy, glucocorticoids and non-steroidal anti-inflammatory drugs though effective, do not have a uniform response pattern. Surgically unresectable inflammatory myofibroblastic tumour above neck should be treated aggressively with combination regimens. Combination of prednisolone with methotrexate has been shown to have good outcome.

[Intra-abdominal soft tissue tumors. What needs to be known to reach the diagnosis with the help of immunohistochemistry, FISH and molecular biology]

Connective tissue tumors located inside the abdomen are a rare heterogeneous group of tumors, except for gastro-intestinal stromal tumors. They may be benign, malignant, or intermediate in terms of biologic potential. Pathologists have to remember the list of all the lesions possibly involved, with their immunohistochemical characteristics, and to know which molecular analyses are needed, with which expected results, and by which team they can be performed. The main tumor types are discussed with diagnostic tools and treatment consequences.

Inflammatory myofibroblastic tumours: a pictorial review

Objectives

To present the most important characteristics of inflammatory myofibroblastic tumours (IMTs) arising in different locations of the body with histological correlation.

Methods

To review the symptoms and main radiological findings of IMTs. On ultrasonography (US), these tumours can appear as hypoechoic or hyperechoic masses and a variable Doppler appearance with increased vascularity. Computed tomography (CT) and magnetic resonance (MR) are the most used imaging tools in their evaluation. On contrast-enhanced CT, IMTs can appear as homogeneous or heterogeneous lesions, with variable enhancement on delayed acquisitions due to fibrosis. These findings are also present on gadolinium contrast-enhanced MR. On T1-weighted and T2-weighted sequences, IMTs usually show low signal intensity reflecting also the presence of fibrotic tissue.

Results

To show the main clinical symptoms and radiological features of IMTs in different locations: head and neck, lung, genitourinary, hepatic, splenic, gastrointestinal tract, mesenteric, muskuloskeletal.

Conclusions

Although IMTs in some organs are not uncommon, they are not usually included in the differential diagnosis of masses. Their radiological features suggest malignant neoplasms, whereas they are not. Consequently, this is an underdiagnosed entity and only after an histological exam could a definitive diagnosis be achieved.

Teaching Points

• Their radiological features suggest malignant neoplasms, whereas they are not

• CT and MR imaging are the most used tools in their evaluation

• IMT is an underdiagnosed entity

• The definitive diagnosis is only after histological exam

Inflammatory myofibroblastic tumour arising in the adrenal gland: a case report

Introduction

Inflammatory myofibroblastic tumour arising in the adrenal gland is exceptional. As far as we are aware, there have been only three previous reports in the literature. We report a fourth case.

Case presentation

A 29-year-old Caucasian man presented with upper quadrant pain due to a 15cm heterogenous adrenal mass that displaced his liver. He underwent an open right adrenalectomy. Histopathological examination showed the mass to be an inflammatory myofibroblastic tumour, a histologically distinctive lesion composed of myofibroblasts, plasma cells, lymphocytes and histiocytes. Ten months later he is well with no sign of recurrence.

Conclusions

The lesion was indistinguishable on imaging from an adrenal cortical tumour. Surgical treatment is the same but inflammatory myofibroblastic tumour carries a favourable prognosis.

A large inflammatory myofibroblastic tumor involving both stomach and spleen: A case report and review of the literature

Inflammatory myofibroblastic tumor (IMT) is a rare, benign neoplasm that most commonly occurs in pediatric patients; it has been described as a pseudosarcomatous proliferation of spindled myofibroblasts mixed with lymphoplasmacytic cells. IMT has been reported in a number of locations throughout the body; however, cases occurring in the gastrointestinal tract are rare and to date, no case involving both the stomach and spleen has been reported. The current study presents a case of an extremely large IMT invading both the stomach and spleen in a 50-year-old female, presenting with a three-month history of left-sided abdominal distension without abdominal pain, fever or vomiting. As the tumor had invaded the stomach and spleen, it was completely excised and concomitantly, the entire stomach and spleen were removed. Histological examination of the biopsy revealed fascicles of spindle cells in a mixed inflammatory background, with inflammatory cells that were immunopositive for vimentin, smooth muscle actin, and negative for anaplastic lymphoma kinase and CD30, confirming the diagnosis of IMT. Four months following local excision of the mass, accompanied by a total gastrectomy and splenectomy, no abdominal distension, abdominal pain, fever or vomiting were observed and no IMT recurrence was identified.

Mesenteric inflammatory pseudotumor: a case report and comprehensive literature review

PURPOSE

This study aims to provide an overview of the literature on mesenteric/omental inflammatory pseudotumors (IPTs).

METHODOLOGY

We present a new case of mesenteric IPT. We also conducted a systematic search of the English-language medical literature using PubMed, Medline, Google, and Google Scholar related to mesenteric or omental IPTs. The following search terms were used in various combinations: inflammatory myofibroblastic tumor, IPT, mesentery, and omentum. The search included articles published in the English language between January, 1978 and April, 2014. Studies were excluded if the full text was unavailable or missing information prohibited comparisons.

RESULTS

A total of 30 reports concerning 36 patients with inflammatory pseudotumors meeting the aforementioned criteria were included. The patients were aged from 10 months to 68 years (mean, 19.98 ± 20.5 years); 12 were female (16.75 ± 16.97 years; range, 10 months to 68 years) and 24 were male (21.6 ± 21.9 years; range, 18 months to 63 years). Detailed clinical and pathologic characteristics of 36 patients with IPTs are provided in Table 1.

CONCLUSION

IPTs may be definitively diagnosed only by histopathological examination and are most effectively treated by resection with negative surgical borders. No consensus has yet been reached regarding when nonsurgical treatment options are most appropriate in management of these lesions. IPTs often recur locally, while distant metastases are very rare. Postoperative close surveillance is essential to detect recurrences early.

Inflammatory myofibroblastic tumours of the maxillary sinus: A brief clinical report and review of the literature

Although inflammatory myofibroblastic tumours (IMTs) have been accepted as a clonal neoplasm, their pathology is poorly understood due to variable presentation. There is no identifiable cause and they are usually observed as tumour growth combined with inflammation. In the current WHO classification, IMTs are designated as intermediate malignancies. In terms of biological potential, IMTs are classified under 'rarely metastasizing'. IMTs are rare in the maxillary sinus but, when reported, can be locally aggressive or even destructive if they invade the orbit. The authors present a brief clinical report describing a five-year-old girl with a slow-growing mass in the right maxillary sinus extending into the lacrimal sac and its management.

Intra-abdominal infantile inflammatory myofibroblastic tumors: A report of three cases

Inflammatory myofibroblastic tumor occurring at intra-abdominal sites in children can be confused with malignancy because of its large size and location. It is a tumor classified as ‘intermediate’ between benign and malignant, but usually benign, with a strong tendency for recurrence. Treatment is surgical excision. Here, we present a brief outline of three such cases presenting as abdominal mass in infants.

Neonatal tuberculosis and cardiac inflammatory myofibroblastic tumor

A 1-month-old neonate was admitted in respiratory distress. Two-dimensional echocardiography and computed tomography scan showed a mass anterior to the left ventricle and right ventricular outflow tract. A biopsy revealed an inflammatory myofibroblastic tumor. A tuberculin test showed an 18-mm diameter induration. Three of the 6 household contacts were also positive for pulmonary tuberculosis. Antituberculosis medication was started. After 1 year, echocardiography and computed tomography scan showed complete resolution of the mass.

Intra-abdominal inflammatory myofibroblastic tumor: Spontaneous regression

Inflammatory myofibroblastic tumors are usually treated by surgical resection. We herein report two cases of intra-abdominal inflammatory myofibroblastic tumors that were unresectable and underwent spontaneous regression without any treatment. Our case report and literature review show that regression is more common in the middle-aged and older male populations. Abdominal discomfort and fever were the most common symptoms, but the majority of patients had no obvious physical signs. There was no specific indicator for diagnosis. The majority of the lesions regressed within 3 mo and nearly all of the masses completely resolved within 1 year. We conclude that the clinical characteristics of inflammatory myofibroblastic tumors are variable and, accordingly, the disease needs to be subdivided and treated on an individual basis. Surgery is always the first-line treatment; however, for those masses assessed as unresectable, conservative therapy with intense follow-up should be considered.

Inflammatory myofibroblastic tumor: an unusual mimicker of childhood intrathoracic tuberculosis

Inflammatory myofibroblastic tumors are rare lesions of uncertain etiology that are often difficult to diagnose because of their myriad clinical presentations. Not uncommon, they mimic persistent pneumonia. We report a 4-year-old girl who presented with prolonged pyrexia, weight loss, severe anemia, hepatosplenomegaly, and nonresolving pneumonia. Initial investigations including flexible bronchoscopy and bronchial washing for usual causes of persistent pneumonia, such as tuberculosis and other infections, were negative. Chest computed tomography revealed a well-defined lesion involving the lingula and left upper lobe with extension into the subpleural space. Pleural tap and biopsy was also noncontributory. Thoracoscopic biopsy was suggestive of an inflammatory myofibroblastic tumor. As the lesion was encasing the major vessels, it was considered inoperable. The patient did not respond to steroid therapy and etoricoxib and later succumbed to the illness. This uncommon tumor should be considered in the differential diagnosis of children who presented with unresolving consolidation with pyrexia.