Inflammatory myofibroblastic tumor with ALK/TPM3 fusion presenting as ileocolic intussusception: an unusual presentation of an unusual neoplasm

Inflammatory myofibroblastic tumor is a rare spindle cell lesion of indeterminate malignant potential occurring in both pulmonary and extrapulmonary tissues. This report describes an unusual presentation of an unusual tumor at an unusual location: an intramural ileal case of inflammatory myofibroblastic tumor presenting with intussusception in a 29-year-old woman. We characterize this tumor through microscopic and ultrastructural analysis, extensive immunohistochemical analysis, ploidy analysis, and Epstein-Barr virus in situ hybridization, and we report the finding of an ALK/TPM3 fusion using fluorescence in situ hybridization.     

Inflammatory myofibroblastic tumor: Clinical,morphological, immunohistochemical and molecular features of a pediatric case

Inflammatory myofibroblastic tumor is an uncommon tumor regarded as “intermediate malignancy”. We present the clinical, pathological and molecular features of a mesenteric inflammatory myofibroblastic tumor in a 9-month-old male infant. The patient was referred to Anna Meyer Children Hospital of Florence, Italy, for an asymptomatic abdominal mass measuring about 7 cm. The lesion was radically excised, and the postoperative course was uneventful. Histologically, the tumor was composed of spindle cells immunopositive for vimentin and desmin admixed with an inflammatory infiltrate. Rearrangement of ALK gene was demonstrated by FISH and immunohistochemistry (cytoplasmic, perinuclear and punctate immunocoloration). The peculiar punctate ALK immunocoloration suggested a possible unusual ALK gene rearrangement involving the CLTC gene.     

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 10 HPFs 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.     

Inflammatory myofibroblastic tumor of the larynx: report of a case and review of the literature

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm, most commonly seen in children and adolescents. It can occur in nearly every part of the body. Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm mostly seen in the lungs, but also in extrapulmonary sites. But it may rarely be seen in the vical cord. We report a case of a 73-year-old men presented with hoarseness and cough. Laryngoscopy reveals a large non-ulcerated, red subepithelial mass arising from the right vical cord. Magnetic resonance imaging (MRI) scan revealed a mass in the right vical cord, and magnetic resonance imaging (MRI) enhanced scan showed the mass of the right vical cord inhomogeneous enhancement. The patient underwent right cordectomy with KTP laser, and further assessment of the tissue demonstrated a pathologic diagnosis of IMT.     

Inflammatory myofibroblastic tumor with valvular involvement: a case report and review of the literature

BACKGROUND: Inflammatory myofibroblastic tumor (IMT) of the heart is extremely rare with unpredictable clinical expression. IMTs, characterized by spindle cells, plasma cells, and a polymorphic inflammatory infiltrate, have a predilection for children and young adults. Clinically, IMT mimics malignancy, making a definitive diagnosis difficult, prior to histopathological examination. METHODS AND RESULTS: We describe a case of an intracardiac IMT in a 69-year-old woman. Histopathological examination of excised specimens revealed a marked, polymorphic, infiltrate of lymphocytes and plasma cells. CONCLUSIONS: Cardiac IMTs are benign lesions with favorable prognosis. Herein, we present this case, along with a review of all cardiac IMTs published after the last review in 2002, with emphasis on clinical, pathologic, and immunohistochemical features.     

Inflammatory myofibroblastic tumor of the posterior mediastinum: an older adult case with anaplastic lymphoma kinase abnormalities determined using immunohistochemistry and fluorescence in situ hybridization

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm that usually occurs in children and young adults. Anaplastic lymphoma kinase (ALK) abnormalities in IMT, determined using immunohistochemistry and/or molecular genetic studies, including fluorescence in situ hybridization (FISH), have almost been limited to children and young adults. In elderly cases of IMT, these ALK abnormalities are very rare. We report on a case of IMT arising in the posterior mediastinum of a 59-year-old Japanese man that showed ALK abnormalities determined using immunohistochemistry and FISH, suggesting the neoplastic nature of a subset of IMTs in older patients similar to those in younger ones and the presence of an additional mechanism(s) that allows them to start to grow late.     

Inflammatory myofibroblastic tumor of the appendix arising after treatment of gastric cancer: a case report and review of the literature

Inflammatory myofibroblastic tumor (IMT) is a rare soft tissue neoplasm of uncertain malignant potential and unclear etiology. IMT involving the appendix is very rare. Herein, we report a case of IMT of the appendix in a gastric cancer patient who was treated with radical gastrectomy and adjuvant systemic chemotherapy. Rare cases of IMT associated with preceding events have been described in other organs/sites, but not in the appendix. A previous intra‐abdominal operation for gastric cancer may contribute to the development of IMT in the appendix as seen in the present patient. To our knowledge, this is the first case of appendiceal IMT arising after a previous operation.     

Inflammatory myofibroblastic tumor of larynx: a benign lesion with variable morphological spectrum

Inflammatory myofibroblastic tumor is a recently characterized lesion, composed of exuberant myofibroblastic proliferation and an inflammatory component. Its etiology remains controversial, as to whether this represents a benign tumor with limited potential to recur or progress. Exaggerated response to trauma or infection has also been implicated. Only a few cases of laryngeal inflammatory myofibroblastic tumor have been described in English after it has been assigned the new name. The prototype lesion, inflammatory pseudotumor, has been best described in association with the lung but has also been reported involving various organs. We report 2 additional cases with a considerable variation in the presentation and histology of the lesion, thus expanding the morphological spectrum of the entity. Both lesions appeared aggressive in clinical presentation. One case had relatively more pleomorphic appearance and increased mitotic rate. Both lesions were surgically resected, and complete voice preservation was achieved. No postoperative complications or recurrence were noticed. This uncommon neoplasm may appear clinically as a large infiltrating mass and may be mistaken as a malignant growth. Conservative resection of the tumor may provide a cure with adequate voice preservation.     

Inflammatory myofibroblastic tumor of bone harboring an ALK gene amplification

Inflammatory myofibroblastic tumor (IMT) is a neoplastic proliferation of myofibroblastic/fibroblastic cells with a variable admixture of inflammatory cells. It primarily affects soft tissue and viscera of children and young adults. IMT occurring in bone is extremely rare. Approximately 50% of IMTs carry a clonal rearrangement of the anaplastic lymphoma kinase (ALK) gene, while other receptor tyrosine kinase gene rearrangements have been seen in a small subset of IMT. Herein, we report the first case of IMT which harbors an ALK gene amplification rather than a rearrangement thus resulting in overexpression of the protein, arising from the femur of a 24-year-old man. Our case provides a novel pathogenesis for IMT. An overview of cytogenetic abnormalities of IMT is also integrated into this report.     

膀胱炎性肌纤维母细胞肿瘤的临床病理观察

目的探讨膀胱炎性肌纤维母细胞肿瘤的临床病理特点、诊断及鉴别诊断。方法采用HE、免疫组织化学（En Vision法）染色方法,观察5例膀胱炎性肌纤维母细胞肿瘤的组织学特点和免疫学表型,并对其中4例进行了随访。结果男性3例,女性2例,年龄10～53岁,平均年龄35岁;肿瘤位于膀胱顶底部3例,左侧壁2例,临床上表现为尿痛、血尿等症状。组织学表现为黏液丰富区和富于细胞区,梭形和星芒状肿瘤细胞散在或束状排列,间质可见大量纤细扩张的小血管网形成,各种炎细胞包括浆细胞、嗜酸性粒细胞、淋巴细胞及中性粒细胞的浸润。免疫组织化学检测显示瘤细胞AE1／AE3、波形蛋白、平滑肌肌动蛋白（SMA）、Calponin全部阳性,3例钙结合蛋白、4例结蛋白和4例间变性淋巴瘤激酶（ALK1）阳性。随访4例目前均存活,无复发。结论膀胱炎性肌纤维母细胞肿瘤是一种具有特殊临床病理特征的少见的中间型具恶性潜能的肿瘤。     

Inflammatory myofibroblastic tumor of small bowel wall in childhood: Report of a case and a review of the literature

Benign intestinal tumors are rare in children, however we describe an inflammatory myofibroblastic tumor (IMT) of the jejunum in a 2-year-old girl who presented with an intestinal obstruction. During laparotomy, an annular mass around the jejunum was resected, from which a histological diagnosis of IMT was made. A review of the literature for this rare entity emphasizes the importance of histological confirmation of its benign nature. Because of the risk of local recurrence, IMT cases should have a long-term follow up.     

Inflammatory pseudotumor of lymph node and spleen: An entity biologically distinct from inflammatory myofibroblastic tumor

Inflammatory pseudotumors (IPTs) of the lymph node and spleen are an uncommon, benign cause of lymphadenopathy and/or splenomegaly that often bear striking clinicopathologic similarities to the inflammatory myofibroblastic tumors (IMTs) found in soft tissues. These tumors have classically been grouped together under the umbrella category of "inflammatory pseudotumor." Recent evidence shows that IMTs are in fact neoplastic processes that often harbor balanced chromosomal translocations involving the ALK kinase gene. These translocations result in expression of ALK kinase in IMTs as assessed by immunohistochemical studies. However, the relationship between IMT and IPT of the lymph node and spleen is uncertain. To determine if ALK tyrosine kinase expression is also present in IPT, 13 cases of IPT (9 involving lymph nodes, 4 splenic lesions) were examined for the presence of ALK tyrosine kinase by immunohistochemical staining on paraffin-embedded tissue. In addition, in situ hybridization studies for Epstein-Barr virus--encoded RNAs (EBER) and immunoperoxidase studies for human herpesvirus-8 (HHV8)--specific proteins were performed. All cases had clinical, morphologic, and immunophenotypic findings typical of IPT and had varying proportions of fibroblastic and inflammatory components. Age ranged from 11 to 75 (median, 40) years; 8 subjects were male, and 5 were female. None of the cases (0 of 13) had positive staining for ALK kinase or HHV8, and in 1 a lymph node (1 of 13) was focally positive for EBV (EBER) by in situ hybridization. The absence of ALK kinase as detected by immunohistochemical studies in IPT of the lymph node and spleen suggests that this entity is biologically distinct from the histologically similar IMT.     

类似卵巢性索肿瘤的子宫肿瘤6例临床病理分析

目的 探讨类似卵巢性索肿瘤的子宫肿瘤(uterine tumor resembling ovarian sex cord tumor,UTROSCT)的临床病理学特征、分子遗传学改变及其鉴别诊断.方法 回顾性分析6例UTROSCT的临床病理学特征、免疫表型等.采用FISH检测JAZF1基因及NCOA2基因易位情况,并复...     

An inflammatory myofibroblastic tumor in liver with ALK and RANBP2 gene rearrangement: combination of distinct morphologic, immunohistochemical, and genetic features

Inflammatory myofibroblastic tumor is an intermediate-grade neoplasm with potential for recurrence and rare metastasis. Rearrangement of the anaplastic lymphoma kinase gene with variable fusion partners and anaplastic lymphoma kinase expression using immunohistochemistry are noted in about half of the tumors. We present a hepatic inflammatory myofibroblastic tumor from a 34-year–old man with an unusual rearrangement between the Ran binding protein 2 and anaplastic lymphoma kinase genes, as well as a peculiar round cell transformation of tumor cells and a unique nuclear membrane expression of anaplastic lymphoma kinase protein. As the fourth reported inflammatory myofibroblastic tumor with this fusion so far, we find that these genetic and morphologic features may be related to a poor clinical outcome. The diagnostic difficulty and other prognostic factors of inflammatory myofibroblastic tumor are also discussed.     

肾恶性横纹肌样瘤15例临床病理及免疫组织化学分析

报道１５例肾恶性横纹肌样瘤（ＭＲＴＫ）的临床病理及免疫组化特点。男女之比为２．８：１。年龄４个月至４岁７个月，平均１岁零６个月。随访１０例，８例均于术后半年内死１０亡，２例健在。典型组织学改变为细胞弥漫排列，多边形，胞浆丰富嗜酸性，核仁突出。部分细胞胞浆内有嗜酸性包涵体，部分病例可见上皮样排列，间质硬化及梭形细胞成分。免疫组化显示１５例Ｖｉｍｅｎｔｉｎ（＋），１２例ＥＭＡ（＋），８例Ｃｙｔｏｋｅｒａｔｉｎ（＋）。结果提示，本瘤是一种好发于婴幼儿、预后差、多表现型的恶性肾肿瘤。可能来源于某种具有双向分化能力的多潜能细胞。