Inflammatory Myofibroblastic Tumor

Hepatic Inflammatory Pseudotumor-Focusing on Its Heterogeneity

Hepatic inflammatory pseudotumors (IPTs) are defined as benign, non-malignant, non-metastasizing tumors characterized by the presence of myofibroblastic spindle cells, hetorogenous populations of inflammatory cells, particularly plasma cells, lymphocytes and macrophages, as well as locations of fibrosis and necrosis without cellular anaplasia or atypical mitoses. Despite subsequent reports in the references, hepatic IPT remains difficult to diagnose; while posing major issues specifically for its differential diagnosis compared with that of other various benign diseases and malignant hepatic tumors. Histopathological findings are always a requisite for confirming the diagnosis, particularly given that the pathogenesis of IPT remains ambiguous to date. Hepatic IPT is a heterogeneous entity in terms of its clinical features, pathological findings, and pathogenesis. Once the diagnosis is confirmed, however, needless surgery such as wedge resection and lobectomy should be avoided. Here, we discuss the heterogeneity of hepatic IPT, its clinical features, pathological findings, and pathogenesis, and describe its differential diagnosis.

Uterine inflammatory myofibroblastic tumor harboring novel NUDCD3-ROS1 and NRP2-ALK fusions: clinicopathologic features of 4 cases and literature review

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm of intermediate biologic potential, which occurs mostly in the lung and abdomen cavity of children and young adults. Uterine IMTs are rare. Herein, we presented clinicopathologic features of 4 uterine IMTs. All four patients were initially diagnosed as leiomyosarcoma by other hospitals and corrected to uterine IMT after pathological consultation. Patient age ranged from 44 to 64 years old. Two cases demonstrated multiple masses. Microscopically, three tumors were composed of fascicular spindled cells with eosinophilic cytoplasm, and the other one was densely composed of spindled and epithelioid cells with bizarre and multinucleated cells. Tumor cells showed variable nuclear atypia, ranging from mild to severe. Prominent inflammatory cell infiltration was found in one case, and necrosis in two tumors. Immunochemistry staining revealed expression of smooth muscle markers in all four tumors, including a-SMA and desmin. Three tumors were positive for ALK protein expression. FISH analysis demonstrated ROS1 rearrangement in one tumor and ALK rearrangement in the other 3 tumors. NGS analysis showed novel NUDCD3-ROS1 and NRP2-ALK fusions in two tumors and TNS1-ALK fusion in the other two tumors. Gene aberrations involving p53 signaling pathway were identified in all four cases. All patients received surgery as primary treatment, and one had neoadjuvant chemotherapy. Three patients recurred within 12 months, and the other one recurred after 7 years. Patients with recurrence were treated with a combination of chemotherapy, targeted therapy, or surgery. In conclusion, the diagnosis of uterine IMTs can be challenging. Ancillary studies including ALK IHC, FISH, and NGS are helpful to establish diagnosis and to discover novel gene rearrangement potentially for targeted therapy.

Multifocal Inflammatory Pseudotumor of the Temporal Bone, Maxillary Sinus, and Orbit

OBJECTIVE

This is the first report of multifocal inflammatory pseudotumor (IPT) involving the temporal bone, orbit and paranasal sinus, and the use of rituximab as adjunctive therapy in multifocal temporal bone IPT.

PATIENT

We describe a 46-year-old man with orbital and maxillary sinus IPT, whose disease progressed despite radiation and steroid burst. He then developed contralateral mastoid disease, otalgia, aural fullness, and hearing loss.

INTERVENTION

He was initiated on rituximab and prednisone therapy. Mastoidectomy with near-total tumor removal was accomplished and histopathology confirmed IPT. A literature review was also performed.

MAIN OUTCOME MEASURE

Tumor regression or recurrence.

RESULT

Despite disease progression after radiation and steroids, his orbital, sinus, and mastoid disease improved after surgery, steroids, and rituximab. A review of four other previously reported cases of multifocal disease involving the temporal bone suggest that multifocal disease may be a more aggressive entity with higher recurrence rate compared with solitary disease. Although surgery and steroids are typically recommended, there is currently no consensus treatment recommendation.

CONCLUSIONS

Multifocal IPT of the temporal bone is a rare but aggressive entity for which surgery and steroid combination therapy should be first line treatment. We suggest rituximab may be an effective adjunctive treatment particularly for recurrent disease or where systemic therapy may be favored.

Animal model of left atrial thrombus in congestive heart failure in rats

The aim of the present study was to develop and study a new model of left atrial thrombus (LAT) in rat with congestive heart failure (CHF). CHF was induced by aortic banding for 2 mo, followed by ischemia-reperfusion (I/R) and subsequent aortic debanding for 1 mo. Cardiac function and the presence of LAT were assessed by echocardiography. Masson's staining was performed for histological analysis. All CHF rats presented with significantly decreased cardiac function, fibrosis in remote myocardium, and pulmonary edema. The incidence rate of LAT was 18.8% in the rats. LAT was associated with severity of aortic constriction, aortic pressure gradient, aortic blood flow velocity, and pulmonary edema but not myocardial infarction or a degree of left ventricular depression. The progressive process of thrombogenesis was characterized by myocyte hypertrophy, fibrosis, and inflammation in the left atrial wall. Fibrin adhesion and clot formation were observed, whereas most LAT presented as a relatively hard "mass," likely attributable to significant fibrosis in the middle and outer layers. Some LAT mass showed focal necrosis as well as fibrin bulging. Most LAT occurred at the upper anterior wall of the left atrial appendage. Aortic debanding had no significant impact on large LATs (>5 mm2) that had formed, whereas small LATs (<5 mm2) regressed 1 mo after aortic release. LAT is found in a rat model of aortic banding plus I/R followed by aortic debanding. The model provides a platform to study molecular mechanisms and potential new pathways for LAT treatment. NEW & NOTEWORTHY It is critically important to have a rodent model to study the molecular mechanism of thrombogenesis in the left atrium. Left atrial thrombus (LAT) is not a simple fibrin clot like those seen in peripheral veins or arteries. Rather, LAT is a cellular mass that likely develops in conjunction with blood clotting. Studying this phenomenon will help us understand congestive heart failure and promote new therapies for LAT.

Intussusception secondary to inflammatory myofibroblastic tumor of the small intestine. Case report

Introduction: Intussusception occurs when part of the intestine slides into an adjacent intestinal segment. Inflammatory myofibroblast tumor is a rare cause of this condition, and is observed in 5% -16% cases in adults.Case presentation: A 41-year-old woman presented with abdominal pain and distension. A exploratory laparoscopy was performed, finding ileocolic intussusception into the transverse colon. Due to uncontrollable bleeding, the procedure was converted to laparotomy; resection and latero-lateral ileocolic anastomosis were performed. Histopathology reported inflammatory myofibroblastic tumor, with a favorable postoperative evolution. The patient was discharged on the sixth postoperative day.Discussion: When located in the small intestine, 57% of the tumors that cause intussusception are benign, including the myofibroblastic tumor in this patient. The symptoms and signs associated with this neoplasm are cramp-like abdominal pain, nausea and vomiting. Although imaging studies may lead to suspect this diagnosis, in most cases it is made intraoperatively. Surgical resection of the affected intestinal segment is curative, with favorable prognosis.Conclusions: This case is considered as a rare cause of intussusception. It had a benign course and is still under study since its pathophysiology has not been fully understood.

Recurrent inflammatory myofibroblastic tumour of the lung: FDG PET/CT scan findings

Inflammatory myofibroblastic tumour (IMT) is a rare neoplasm, occurring most often in children and young adults. IMTs have intermediate biological behaviour with the chance of local invasion, recurrence and even distant metastasis. Wide range of clinical presentations makes the precise diagnosis of IMT more challenging. The best method for definitive diagnosis is tissue biopsy and newer imaging modalities including fleurodeoxyglucose (FDG) positron emission tomography (PET)/CT are useful tools in detection of disease recurrence or distant metastasis. Complete surgical resection is the best-known treatment for this tumour. Here we are presenting an IMT case in a 12-year-old girl in which her recurrent pulmonary IMT was diagnosed based on FDG PET/CT findings and referred for further salvage treatment. Overall imaging modalities are not specific, but PET/CT scan can be useful tool for evaluation of IMT regarding initial staging and restaging to assess treatment response and recurrence.

Hepatogastric Inflammatory Pseudotumor Presumably Deriving from Prior Amebic Infection

Introduction

Inflammatory pseudotumor is a rare entity with a clinical and radiographic presentation that is difficult to differentiate from malignancy. This is a case report of a large hepatogastric inflammatory pseudotumor that presumably developed from a prior amebic pseudocyst.

Case Report

A 14-year-old boy presented with increasing vomiting, epigastric pain, dysphagia, asthenia and weight loss. The clinical history included an amebic infection at the age of 2 months. Instrumental investigations revealed an 8 x 6 cm left subdiaphragmatic mass inseparable from the gastric fundus, which appeared to infiltrate the left hepatic lobe. Surgery disclosed a bulky mass adhering to the gastric fundus and left hepatic lobe that prompted total gastrectomy, resection of the second and third hepatic segments, and Roux-en-Y esophagojejunal loop anastomosis. Histology subsequently confirmed that this was a pseudocyst with a large calcified nucleus surrounded by myofibroblastic proliferation associated with a diffuse lymphoplasmacytic infiltrate affecting the gastric wall and hepatic parenchyma, hence the final diagnosis of inflammatory pseudotumor, presumably in response to a prior amebic pseudocyst.

Conclusions

Inflammatory pseudotumor is a rare entity that is seldom found in the stomach. The particular interest of the present case lies in the fact that it developed in the stomach and liver, presumably deriving from a previous amebic pseudocyst.

Pulmonary Inflammatory Myofibroblastic Tumor in Children: A Case Report and Brief Review of Literature

The inflammatory myofibroblastic tumor (IMT) is a rare lesion of unclear etiology and variable clinical course, consisting of a proliferation of fibroblasts and myofibroblasts, mixed with inflammatory cells. Synonyms of IMT are inflammatory pseudotumor and plasma cell granuloma reflecting the alleged inflammatory nature attributed to this lesion, even though this heterogeneity in the disease denomination is probably involved in a dispersion of the literature data. Among primary pulmonary neoplasms, it represents the most frequent endobronchial tumor of childhood and beyond the lung it has been described mainly in the bladder, mediastinum and mesentery. Despite having a tendency for local recurrence, the risk of distant metastasis is low. Clinical presentation depends on localization therefore lung peripheral lesions are often asymptomatic resulting in a delayed diagnosis. Radiological findings can suggest the diagnosis that must be confirmed by histopathology assessment. The tumor has been characterized by the application of immunohistochemical techniques, molecular biology and cytogenetics, which are very precious for the diagnosis. The therapeutic approach consists in the complete surgical excision of the lesion that normally ensures excellent survival. Due to the potential risk of recurrence, close clinical trial is indicated. To date only 24 cases of pulmonary IMT have been described, although the prevalence is probably higher. We present a case report of a 3-year-old girl with pulmonary IMT and a brief review of known literature cases in order to highlight the most common clinical presentations, the most useful diagnostic tools and therapeutic approach.

Myxoid Mesenchymal Tumors of the Uterus: An Update on Classification, Definitions, and Differential Diagnosis

Tumors with a predominant myxoid stroma are rare in the uterus. When encountered, however, they pose a diagnostic challenge. Traditionally myxoid leiomyosarcoma has been the most important consideration in this category, given its adverse prognosis and deceptively bland morphology. Conventional features of malignancy are variably present; in contrast, an infiltrative tumor border is a consistent pathologic characteristic. More recently, previously under-recognized lesions have been identified, in part due to our growing knowledge of their underlying molecular alterations: uterine inflammatory myofibroblastic tumor frequently harbors ALK rearrangements and a novel ZC3H7B-BCOR gene fusion has been described in a subset of myxoid high-grade endometrial stromal sarcomas. These tumors need to be distinguished from myxoid leiomyosarcoma, as by comparison have a less aggressive course and are amenable to targeted treatments. In addition, uterine mesenchymal tumors with malignant potential need to be distinguished from benign tumors and epithelial and mixed malignancies. This review aims to discuss our current understanding of the most common uterine myxoid neoplasms: their clinical features, their distinguishing histopathologic, immunohistochemical, and molecular features and the clues and pitfalls in their diagnosis.

Cytohistological and immunohistochemical characteristics of spindle-shaped mesenchymal neoplasms occurring in the gastrointestinal tract

The purpose of the present review is to analyze the cytohistological and immunohistochemical characteristics of spindle-shaped mesenchymal gastrointestinal neoplams (MGNs), a group of unusual neoplastic conditions with different biological behavior. These tumors exhibit clinical pictures strictly related to the site of origin and dimensions, even if they appear generally with an intramural localization. This latter point may suggest an useful application of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), mainly followed by the cell-block procedure (CBP) in the differential diagnostic approach. First of all, we discuss the most common entity of MGNs represented by gastrointestinal stromal tumors (GISTs), analyzing the morphologic characteristics and stressing the strength of immunohistochemical algorithm for diagnostic purposes. Successively, we have reported the less common group of spindle-shaped MGNs comprehensive of those arising elsewhere the soft tissues, such as leiomyomas, leiomyosarcomas, schwannomas, inflammatory myofibroblastic tumor and intra-abdominal desmoid fibromatosis. Finally, very uncommon spindle-shaped MGNs, like clear cell, follicular dendritic cell, undifferentiated pleomorphic and radiation-induced sarcomas as well as spindle cell dedifferentiated liposarcomas, have been briefly mentioned.

A primary inflammatory myofibroblastic tumor of the scapula in a child: imaging findings

Inflammatory myofibroblastic tumor (IMT) is an uncommon tumor characterized by inflammatory cell infiltration and differentiated myofibroblastic spindle cells. IMT was first described in the lung and retroperitoneum. Occurrence in bone has been well described in the maxilla and occasionally in the long bones in the adult population. We present a unique case of IMT arising primarily from the scapula in an 8-year-old patient, not described previously in the pediatric or adult literature. Imaging demonstrated an ill-defined and aggressive osteolytic lesion with cortical bone destruction associated with an important soft tissue component that extended into the adjacent muscles. Histologically, the tumor was composed of spindle and polygonal cells distributed in an inflammatory background with different proportions of plasma cells, lymphocytes, eosinophils and neutrophils. The absence of cellular atypia helped to differentiate this entity from malignant spindle cell tumors, and imaging could differentiate the tumor from the nontumoral inflammatory reaction.

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.

Obstructive pseudotumor of tuberculosis in a young woman: a rare presentation

Retroperitoneal pseudotumor is an extremely rare presentation of extrapulmonary tuberculosis. The diagnosis of this paucibacillary disease is difficult which is usually misdiagnosed as a malignant tumor. High index of suspicion is required for early diagnosis and treatment of retroperitoneal pseudotumor which can affect prognosis of this disease. Because of its rarity and difficult diagnosis, we report an 18-year-old immunocompetent girl who presented with abdominal pain and vomiting. Upper endoscopy showed an exudative mass between the second and third parts of duodenum. Abdominal computed tomography (CT) revealed a large retroperitoneal mass with extension into small bowel. Exploratory laparotomy and histopathological examination of tissue showed calcified granuloma. Ziehl-Neelsen staining and PCR confirmed the tuberculosis. The patient was successfully treated with standard antituberculosis therapy.

Inflammatory myofibroblastic tumor of the thigh without bone involvement: a case report

Inflammatory myofibroblastic tumors are rare, and those located in the extremities without bone involvement are even rarer. We present the case of a 61-year-old Chinese male patient with an inflammatory myofibroblastic tumor of the right thigh. It was excised and a histopathologic examination revealed an inflammatory myofibroblastic tumor. This case is presented by virtue of its rare location.

Inflammatory myofibroblastic tumor with RANBP2 and ALK gene rearrangement: a report of two cases and literature review

Abstract

Inflammatory myofibroblastic tumors (IMTs) are categorized as intermediate biologic neoplasms, whereas IMTs with genetic features of ran-binding protein 2 (RANBP2) and anaplastic lymphoma kinase (ALK) rearrangement (IMT-RAs) are possibly related to a more aggressive clinical course. However, fewer than 10 cases of IMT-RA have been reported to date. Herein, we present 2 new cases of IMT-RA in which both tumors recurred quickly after primary surgery; one patient died 3 months later from the disease, and the other patient has been living with the disease for 12 months. IMT-RAs are characterized by noncohesive epithelioid and rounded tumoral cell morphology, commonly derived from pelvic and peritoneal cavities, and frequently show larger tumor sizes. The relation between the clinicopathologic features and poor prognosis of IMT-RA is discussed.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3314123381007714

Colonic inflammatory myofibroblastic tumours: an institutional review

AIM

The aim of the study was to present the largest series of colonic inflammatory myofibroblastic tumour (C-IMFT) in the literature so far and to provide a review of this condition.

METHOD

A retrospective review was carried out of a consecutive series of patients diagnosed with a C-IMFT at a community-based hospital with a specialized gastrointestinal unit between 2002 and 2011. The main outcome measures were success rate and postoperative complications. Using a set of terms we searched the PubMed database for papers published on C-IMFT. We reviewed the data from these studies and case reports.

RESULTS

There were seven patients with a histopathologically proven C-IMFT. The patients' mean age was 39 ± 11.3 years. Four presented with clinical features of intestinal obstruction of varying severity and three with symptoms of anaemia. Complete surgical resection with end-to-end anastomosis was performed. The gross morphology included polypoidal myxoid tumours that served as a lead point for intussusception in two cases, a whorled mass in two and a circumferential infiltrative tumour in three. Microscopically, all tumours had typical features of IMFT with a variable expression of anaplastic lymphoma kinase (ALK-1) and tumour-free resection margins. All patients were well without local recurrence or metastasis at a mean follow-up of 46.8 ± 11.9 months.

CONCLUSION

Surgical resection is effective for this rare tumour which mostly behaves in a benign manner. Our review supports the need for patients to be followed up for long periods because of the possibility of metastasis or late recurrence.

Primary inflammatory myofibroblastic tumor of the breast with rapid recurrence and metastasis: A case report

Primary inflammatory myofibroblastic tumor (IMT) of the breast is extremely rare; only 19 cases have been reported in the English literature. In the present study, we present a case of IMT in a 56-year-old female patient who was admitted to our hospital due to a mass found in her right breast. Mammogram and ultrasound revealed a well-circumscribed mass and surgery was performed. Histopathologically, the lesion was composed of spindle and inflammatory cells, including plasma cells and lymphocytes. Mitotic figures were not observed. Immunohistochemically, the tumor cells were positive for SM-actin, anaplastic lymphoma kinase (ALK) and vimentin and focal positive for desmin, but negative for NSE, S-100, CD117, CD34, NF, CD21, CD35 and CD68. Thus, we made a diagnosis of IMT and advised regular follow-up. However, the patient had local recurrence and metastasis to the left groin area 3, 7 and 10 months after the initial surgery. Notably, the histopathological characteristics of the recurrent and metastatic foci were similar to those of the initial specimen, but mitotic figures were clearly observed. Thus, we conclude that IMT shows occasionally malignant biological behavior although it is a neoplasm of intermediate biological potential that frequently recurs and rarely metastasizes. We advise that clinical physicians should regularly follow up patients after focal resection for IMT.

Klatskin-like lesions

Hilar cholangiocarcinoma, also known as Klatskin tumour, is the commonest type of cholangiocarcinoma. It poses unique problems in the diagnosis and management because of its anatomical location. Curative surgery in the form of major hepatic resection entails significant morbidity. About 5-15% of specimens resected for presumed Klatskin tumour prove not to be cholangiocarcinomas. There are a number of inflammatory, infective, vascular, and other pathologies, which have overlapping clinical and radiological features with a Klatskin tumour, leading to misinterpretation. This paper aims to summarise the features of such Klatskin-like lesions that have been reported in surgical literature.

Inflammatory myofibroblastic tumor of the lung: a benign lesion with aggressive behavior

Inflammatory myofibroblastic tumor is a rare solid tumor that most often affects children and young adults. They present as myofibroblastic cell proliferations accompanied by inflammatory cells made up mostly of plasma cells. Although benign, the tumor may be very aggressive locally. In this report we describe a 22-year-old woman with primary invasive myofibroblastic tumor of the left lower lobe leading to a left pneumonectomy.

Rare gastric inflammatory myofibroblastic tumor in an adult woman: a case report with review of the literature

Inflammatory myofibroblastic tumor (IMT) of the stomach is extremely rare and its prognosis is unpredictable. We present a 37-year-old woman with a gastric IMT. She presented epigastric pain since 2 months, anemia and weight loss associated. Physical examination showed cutaneous pallor and mild abdominal tenderness in the epigastrium. Abdominal ultrasonography showed a tumor near the pancreas and the CT scan revealed that the lesion was arising from the stomach. Upper endoscopy showed a submucosal lesion of approximately 7.5 cm located in the posterior wall of the gastric body such as a gastrointestinal stromal tumor (GIST). The patient underwent a subtotal gastrectomy and Billroth I reconstruction. The histopathological and immunohistochemical analysis revealed an IMT that originated from the gastric wall.

Inflammatory myofibroblastic tumours of the respiratory tract: paediatric case series with varying clinical presentations

OBJECTIVES

To highlight the clinical importance of inflammatory myofibroblastic tumours of the respiratory tract in children, and to present a case series of three children which illustrates this tumour's variable clinical presentation.

CASE HISTORY

The series includes: a nine-year-old girl with a diagnosis of juvenile idiopathic arthritis, who presented with finger clubbing and was found to have an inflammatory myofibroblastic tumour in her right upper lobe; a 15-year-old adolescent with a left main stem bronchial inflammatory myofibroblastic tumour, who presented with breathlessness and chest pain; and a 12-year-old girl with a tracheal inflammatory myofibroblastic tumour who presented with stridor. In each case, the tumour was resected surgically.

CONCLUSION

Inflammatory myofibroblastic tumour are a rare but clinically important and pathologically distinct lesion of the respiratory tract in children. The cases in this series highlight some of the varied clinical presentations of inflammatory myofibroblastic tumours, and illustrate some of this tumour's different anatomical locations within the paediatric respiratory tract.

Inflammatory myofibroblastic tumour of liver masquerading as hilar cholangiocarcinoma

There is a wide variety of inflammatory and benign neoplastic disorders of the biliary system that mimic cholangiocarcinoma in terms of clinical manifestations and imaging findings. Inflammatory myofibroblastic tumour of the bilary tract is one such condition, which is extremely rare but benign. Like cholangiocarcinoma this condition presents as painless progressive obstructive jaundice and it is often difficult to differentiate between the two prior to laparotomy, with the usual investigative modalities. Diagnosis is usually established by the characteristic histopathology findings in biopsy specimen. Newer diagnostic modalities directed at obtaining preoperative biopsy of the lesion appear promising in differentiating benign from malignant biliary lesions, but their routine use is yet to become standardised. Until then, awareness of doctors about the existence of such benign entities might prompt a less aggressive treatment approach while dealing with atypical hilar lesions of liver.

Inflammatory myofibroblastic tumor of bone: two cases occurring in long bone

Inflammatory myofibroblastic tumor (IMT) is an unusual tumor composed of differentiated myofibroblastic spindle cells usually accompanied by numerous plasma cells and lymphocytes. IMT was originally described in the lung; occurrence in a long bone is rare. We present two examples of IMT arising in a long bone: one in the humerus and one in the femur. In both cases, imaging shows a poorly delineated osteolytic lesion with cortical bone destruction that aggressively extends into surrounding soft tissue. Histologically, the lesion is dominated by differentiated spindle cells with aprominent collagenous stroma and an inflammatory component including plasma cells and lymphocytes, and with positive immunoreactivity for anaplastic lymphoma kinase. The absence of cytologic atypia helps differentiate this lesion from malignant spindle cell tumors.

Anaplastic lymphoma kinase expression and prognosis in inflammatory myofibroblastic tumours of the maxillary sinus

Inflammatory myofibroblastic tumours (IMT) of the nasal cavity and nasal sinus are rare and, although over 50 cases have been reported in the English-language literature, their precise aetiology and biological behaviour have not been elucidated. Recent studies suggest that anaplastic lymphoma kinase (ALK)-positive tumours have a very low risk of metastasis, but ALK reactivity does not appear to correlate with recurrence. Between March 2002 and December 2008, we encountered three cases of maxillary sinus IMT and investigated them to determine the clinicopathological course, prognosis and immunohistochemical expression of ALK. Two of the patients died < 13 months after the initial diagnosis and the third had multiple recurrences. All three cases were immunohisto chemically negative for ALK expression. IMT of the sino-nasal tract is rare and may undergo malignant transformation in a minority of cases. The three cases manifested progressive extension with bone destruction and multiple recurrences, and two cases had a fatal outcome and one case had high recurrence.

Primary gastric inflammatory myofibroblastic tumor: a clinicopathologic and immunohistochemical study of 5 cases

Primary gastric inflammatory myofibroblastic tumors are rare. Here we report on 5 such cases (4 males and 1 female, age range 36-45 years). Their presenting symptoms included abdominal mass (5 patients), abdominal pain (4 patients), and upper gastrointestinal hemorrhage (1 patient). Tumor size ranged from 4.5 to 8 cm in the greatest dimension. Histologically, these tumors showed three patterns: myxoid hypocellular, fascicular, and hyalinized. A lymphoplasmacytic infiltrate was present in all 5 tumors. One to two mitotic figures were recognized in 10 high power fields (HPFs) in 4 patients and focally up to 5 in 10HPFs in 1 patient. No prominent nuclear atypia or necrosis was observed. ALK, smooth muscle actin, and vimentin staining were observed in all tumors. One tumor focally expressed desmin. S-100, CD21, CD34, CD35, CD68, and CD117 were negative in all IMTs. The patients were followed up for 2-5 years (mean 3.4 years), and none of them had tumor metastasis or died. Only one patient developed local recurrence and is now alive with no evidence of disease after the second surgery (11 months after the second surgery). Our results indicate that primary gastric IMTs have an intermediate behavior as seen at other sites.

[Case report: a patient with bladder sarcoma exclusively treated with transurethral resection with long-term follow-up]

Sarcoma is a rare malignant lesion in the urinary bladder and remains unknown of its natural history. We report a case of primary bladder sarcoma with long-term follow-up. A 35-year-old man suddenly presented with severely gross hematuria. Computer tomography was showed solitary lesion at the anterior wall of the urinary bladder without distant metastases. Transurethral resection of the bladder tumor (TURBT) was performed. Pathologic findings demonstrated sarcoma in the urinary bladder without remnant lesions. Immunohistochemical staining using conventional antibodies was not classified as the origin of this sarcoma. There have been no signs of recurrence during twenty years' follow-up after the treatment.

Inflammatory myofibroblastic tumors in two dogs

Two soft tissue masses from different locations in 2 dogs were submitted for histopathologic examination. Each was well demarcated and consisted of interweaving streams of bland spindle cells among which numerous plasma cells and lymphocytes were scattered. All the spindle cells reacted strongly to antibodies against vimentin and calponin, whereas a subset of the spindle cells expressed smooth muscle actin and desmin. Immunohistochemistry results were consistent with a myofibroblastic derivation for the spindle-cell population and the diagnosis of inflammatory myofibroblastic tumor (IMT) was made. This is the second report of IMT in the veterinary literature.

Metachronous inflammatory myofibroblastic tumour in the temporal bone: case report

Objective:

We report an extremely rare case of metachronous inflammatory myofibroblastic tumour in the temporal bone.

Method:

Case report and review of the world literature on metachronous inflammatory myofibroblastic tumour.

Results:

Inflammatory myofibroblastic tumour in the temporal bone is rare, and metachronous inflammatory myofibroblastic tumour in the temporal bone has never been reported in the English medical literature. We report a case of inflammatory myofibroblastic tumour in the right temporal bone in a 27-year-old woman presenting with right-sided otalgia and progressive hearing loss. A metachronous lesion was discovered in the left temporal bone one year later. The patient underwent surgical excision of the tumour via canal wall down mastoidectomy for both lesions. Long term steroids were prescribed after both surgical procedures. At follow up three years after the last procedure, the patient remained free of disease.

Conclusion:

To the best of our knowledge, this is the first reported case of metachronous inflammatory myofibroblastic tumour in the temporal bone.

Mimics of cholangiocarcinoma: spectrum of disease

Cholangiocarcinoma is the second most common primary malignant hepatobiliary neoplasm, accounting for approximately 15% of liver cancers. Diagnosis of cholangiocarcinoma is challenging and the prognosis is uniformly poor, with recurrence rates of 60%-90% after surgical resection. A wide spectrum of neoplastic and nonneoplastic conditions of the biliary tract may masquerade as cholangiocarcinoma, adding to the complexity of management in patients suspected to have cholangiocarcinoma. Mimics of cholangiocarcinoma constitute a heterogeneous group of entities that includes primary sclerosing cholangitis, recurrent pyogenic cholangitis, acquired immunodeficiency syndrome cholangiopathy, autoimmune pancreatitis, inflammatory pseudotumor, Mirizzi syndrome, xanthogranulomatous cholangitis, sarcoidosis, chemotherapy-induced sclerosis, hepatocellular carcinoma, metastases, melanoma, lymphoma, leukemia, and carcinoid tumors. These entities demonstrate characteristic histomorphology and variable clinicobiologic behaviors. The imaging findings of these disparate entities are protean and may be indistinguishable from those of cholangiocarcinoma. In most cases, a definitive diagnosis can be established only with histopathologic examination of a biopsy specimen.

Complete resection of pulmonary inflammatory pseudotumors has excellent long-term prognosis

OBJECTIVE

Pulmonary inflammatory pseudotumor is an uncommon disease, often with a benign presentation. However, invasion of adjacent thoracic organs, local recurrence, and distant metastases have been described, and the best management strategy remains unclear. We present a single large institutional experience in patients with pulmonary inflammatory pseudotumor and propose guidelines for treatment of this patient population.

METHODS

A retrospective study was performed to review all patients who underwent resection for pulmonary inflammatory pseudotumor between 1974 and 2007.

RESULTS

A total of 25 patients were treated with pulmonary inflammatory pseudotumor at the Marie Lannelongue Hospital. The mean age was 33 years. Two patients were referred after an incomplete resection. One patient presented with cerebral metastasis. We performed a complete resection in all patients: wedge resection (n = 7), lobectomy (n = 6), sleeve arterial lobectomy (n = 1), lobectomy with thoracic inlet exenteration (n = 2), bilobectomy (n = 2), pneumonectomy with brain metastasectomy (n = 1), sleeve pneumonectomy (n = 2), sleeve main bronchus or tracheal resection (n = 2), wedge with sleeve main pulmonary artery resections (n = 1), and sleeve pneumonectomy with esophageal, aortic arch, and right pulmonary artery resection (n = 1). No adjuvant therapy was given to any patients. Postoperative 30-day mortality and morbidity rates were 4% and 8%, respectively. With a mean follow-up of 80 months (range 4-369 months, 100% follow-up), actuarial 10-year survival was 89%. One patient died of an extensive sarcomatous recurrence 2 years after surgery.

CONCLUSION

Pulmonary inflammatory pseudotumor is a malignant disease affecting young patients with local invasion, distant metastasis, local recurrence, and sarcomatous degeneration. A complete resection should always be performed at initial presentation because of its high likelihood of cure with aggressive management.

Inflammatory myofibroblastic tumor of the central nervous system and its relationship to inflammatory pseudotumor

Inflammatory myofibroblastic tumor (IMT) is a distinctive spindle cell lesion and occurs primarily in soft tissue. Recent evidence suggests a neoplastic nature, although historically, both neoplastic and nonneoplastic processes were combined in this category. Originally described as a nonneoplastic process, the term inflammatory pseudotumor (IP) has been used synonymously with IMT. IMTs have been linked to ALK gene (2p23) rearrangements, and some have suggested an association with the human herpesvirus 8 (HHV-8). IMT in the central nervous system (CNS) is rare, its characteristics are poorly defined, and its relation to similar tumors at other sites is unclear. To better characterize IMT within the CNS, we studied clinicopathologic features of 6 IMTs and compared them with 18 nonneoplastic lesions originally classified as IP. The IMT group consisted of 2 male and 4 female patients with a median age of 29 years. Of the six IMTs, 5 occurred within the cerebral hemispheres, and one was in the posterior fossa. All tumors were composed of neoplastic spindle cells and a variable amount of inflammatory infiltrate. Eighteen IPs included in this study consisted of predominantly inflammatory masses occasionally seen in the setting of systemic diseases. Only 1 IMT and none of the IPs recurred during the follow-up period. Four IMTs had either ALK protein overexpression or 2p23 rearrangement, and 1 case demonstrated both. None of the IPs were positive for ALK. Neither IMT nor IP cases demonstrated HHV-8 expression. We suggest that IMT in the CNS is distinct from the nonneoplastic IP, and distinguishing IMT from nonneoplastic lesions should enable better decisions for patient management.

Inflammatory pseudotumor associated with Mycobacterium tuberculosis infection

BACKGROUND

Inflammatory pseudotumor is a relatively rare entity; originally identified in the lung, it has been described in multiple extrapulmonary anatomic locations.

CASE REPORT

We report on the unusual case of an inflammatory pseudotumor associated with Mycobacterium tuberculosis infection, which was initially mistaken for a renal malignancy both in clinical and radiological settings. We additionally present three brief reviews concerning: (1) infectious agents postulated to induce morphological changes of an inflammatory pseudotumor; (2) mycobacterial pseudotumors; and (3) distinction from inflammatory myofibroblastic tumors of the renal pelvis.

CONCLUSIONS

The present case highlights the diagnostic importance of PCR-based detection of mycobacterial DNA in granulomatous tissue responses. It is of crucial importance that clinicians are aware of this unusual manifestation of mycobacterial infection to ensure that pertinent laboratory evaluation is employed and appropriate treatment is administered in order to avoid potential clinical implications.

Soft tissue tumors of the urinary bladder, Part I: myofibroblastic proliferations, benign neoplasms, and tumors of uncertain malignant potential

Most bladder tumors arise from the urothelium. However, there are several uncommon but significant bladder lesions that must be differentiated from urothelial carcinomas. These include both benign and malignant spindle cell lesions. The first half of this 2-part review will describe benign myofibroblastic proliferations including inflammatory myofibroblastic tumor and postoperative spindle cell nodule; benign neoplasms including leiomyoma, hemangioma, neurofibroma, and schwannoma; and tumors of uncertain malignant potential including paraganglioma, granular cell tumor, and perivascular epithelioid cell tumor. Common clinical presentations, morphological characteristics, and immunohistochemical features are described to aid the practicing pathologist in the identification of these entities. This review also describes current theories as to the pathogenesis of inflammatory myofibroblastic tumor and postoperative spindle cell nodule and details the current molecular markers identifying several of these lesions.