Inflammatory myofibroblastoma mimicking cavernous hemangioma in the liver.

A 37-year-old female patient was admitted to the hospital with a large liver mass, diagnosed as hepatic inflammatory myofibroblastic tumour (HIMT), characterized by unique radiographic features and predominantly occurring in adults. HIMT consists of myofibroblast spindle cells infiltrated by plasma cells and/or lymphocytes, with an unclear aetiology linked to factors like infection and immune response. Treatment typically involves surgical resection, with chemotherapy or targeted therapy options for cases of incomplete resection or metastasis, emphasizing the need for precise diagnosis and tailored treatment strategies.

Unresectable infantile myofibroma discovered in utero.

The authors present a case of a proliferative nodule located beneath an infant's lower lip that was initially discovered on prenatal ultrasound and fetal magnetic resonance imaging (MRI). Biopsy revealed a smooth muscle actin-positive spindled cell proliferation with hemangiopericytoma-like vessels consistent with infantile myofibromatosis (IM). Since the location prevented surgical management, the clinicians opted to observe the lesion. Ultimately, the lesion fully regressed on its own confirming conservative management is an option for isolated IM.

Inflammatory myofibroblastic tumor in the urinary bladder in a dog.

An 8-year-old castrated male Maltese dog was presented with a urinary bladder mass, urolithiasis, and hematuria. A solitary, pedunculated, intraluminal mass on the caudodorsal wall was identified with extensive irregular bladder wall thickening, and the mass was surgically removed. Postoperative histopathology demonstrated a submucosal lesion comprising spindle cells with marked inflammatory cell infiltration, without malignant changes. Immunohistochemical staining revealed vimentin and desmin positivity in the mass. An inflammatory myofibroblastic tumor (IMT) was definitively diagnosed. No recurrence was observed during a 43-month follow-up period. Although IMTs are rare in dogs, they should be considered a differential diagnosis for mass-like urinary bladder lesions accompanying a chronic inflammatory disease process. Key clinical message: Canine IMT should be included in the differential diagnoses of bladder masses, especially when dogs exhibit chronic irritation and inflammation.

Tumeur myofibroblastique inflammatoire de la vessie chez un chienUn chien maltais mâle castré de 8 ans a été présenté avec une masse à la vessie, une lithiase urinaire et une hématurie. Une masse intraluminale pédonculée solitaire sur la paroi caudodorsale a été identifiée avec un épaississement important et irrégulier de la paroi vésicale, et la masse a été retirée chirurgicalement. L'histopathologie postopératoire a mis en évidence une lésion à la sous-muqueuse comprenant des cellules fusiformes avec une infiltration cellulaire inflammatoire marquée, sans modification maligne. La coloration immunohistochimique a révélé une positivité à la vimentine et à la desmine dans la masse. Une tumeur myofibroblastique inflammatoire (IMT) a été définitivement diagnostiquée. Aucune récidive n'a été observée au cours d'une période de suivi de 43 mois. Bien que les IMT soient rares chez le chien, ils doivent être considérés comme un diagnostic différentiel des lésions de la vessie de type masse accompagnant un processus de maladie inflammatoire chronique.Message clinique clé:L'IMT canine doit être incluse dans les diagnostics différentiels des masses vésicales, en particulier lorsque les chiens présentent une irritation et une inflammation chroniques.(Traduit par Dr Serge Messier).

Inflammatory Myofibroblastic Tumor of the Sigmoid Colon in an Infant: A Case Report and Literature Review.

Inflammatory myofibroblastic tumor (IMT) infrequently involves the sigmoid colon, and has not previously been described in an infant sigmoid colon.An inflammatory myofibroblastic tumor arose from the sigmoid colon of an 11-month-old boy, confirmed by anaplastic lymphoma kinase (ALK), smooth muscle actin (SMA) and desmin immunohistochemical staining. The patient recovered well after complete resection of the tumor.Sigmoid IMT can occur in infancy. This eighth case is the youngest so far. The child did well after surgical resection.

Intraocular myofibroblastoma tumour of the ciliary body: a case report and literature review.

BACKGROUND: Inflammatory Myofibroblastoma Tumors (IMTs) are extremely tumour rare in the intraocular. CASE PRESENTATION: A ciliary body tumor was found under slit lamp biomicroscopy in a 55-year-old male first diagnosed with cataract. Then this patient underwent trans-sclera resection via partial lamellar sclerouvectomy and par plans vitrectomy to remove the mass. Hematoxylin and eosin (HE) staining and immunohistochemistry findings showed that the characteristics of the tumor were consistent with IMT. CONCLUSIONS: We reported a rare case of intraocular IMT, which is confirmed by H&E staining, and IHC positive staining for Vimentin, Desmin and ALK, while negative staining for SMA, S-100, ki-67, CK, CD68, and calponin.

Superficial myofibroblastoma of the lower female genital tract: A clinicopathological analysis of 15 cases.

OBJECTIVE: To describe the clinicopathological features and differential diagnoses of 15 cases of superficial myofibroblastoma, a rare mesenchymal tumor involving the lower female genital tract. METHODS: The clinicopathological data and immunohistochemical findings were retrospectively analyzed in 15 cases of superficial myofibroblastoma. Meanwhile, a systematic literature review was conducted. RESULTS: The age of patients ranged from 34 to 73 years (median, 49 years). Most patients presented with nodular or polypoid masses ranging in size from 0.4 cm to 6.5 cm. Twelve tumors were located in the vagina, two in the vulva, and one in the cervix. Microscopically, the tumor was located in the subepithelial tissue, with a clear boundary and without capsule on the surface. The tumor cells were spindle, oval, stellate or wavy, and arranged in various architectural patterns of reticular, fascicular, wavy and disorderly patterns. There were no obvious cellular atypia and mitotic figures. Thin collagen fibers and thin-walled vessels could be observed in all cases. Most cases were diffusely and strongly reactive to Vimentin (12/12), Desmin (14/15), ER (15/15) and PR (13/14). Variable immunoreactivity for CD34 (8/15), Caldesmon (2/8), SMA (4/14) and CD99 (4/5) were observed. The tumors showed a low Ki67 proliferative index (≤5 %). Follow-up information was available in 10 patients and there was no evidence of recurrence or metastasis. CONCLUSIONS: Superficial myofibroblastoma is a rare benign tumor that originates from the hormone-sensitive, subepithelial mesenchymal tissue of the lower female genital tract, and should be differentiated from other mesenchymal tumors.

Uterine inflammatory myofibroblastic tumor: First report of a ROS1 fusion.

Inflammatory myofibroblastic tumor (IMT) of the uterus is an uncommon mesenchymal neoplasm that frequently harbors ALK rearrangements. In this report, we describe the first uterine IMT with a FN1-ROS1 fusion, which occurred in a 43-year-old woman who presented with menorrhagia. Morphologically, the well-circumscribed 3 cm tumor was comprised of compact and myxoid foci of relatively bland spindle cells admixed with scattered chronic inflammatory cells limited to the myxoid areas. ROS1 showed moderate cytoplasmic granular staining in < 30% of cells in the myxoid foci, while ALK was negative. RNA sequencing detected a FN1-ROS1 rearrangement that fused FN1 exon 37 to ROS1 exon 34. Although non-ALK-rearranged uterine IMTs are exceedingly rare, this example highlights the importance of performing ROS1 immunohistochemistry and/or molecular analysis in ALK-negative uterine neoplasms morphologically compatible with IMT.

Myofibroblastoma of the breast showing rare palisaded morphology and uncommon desmin- and CD34-negative immunophenotype: A case report.

Myofibroblastoma is a rare benign mesenchymal tumor typically arising in the breast. We report a diagnostically challenging case of myofibroblastoma of the breast showing a rare palisaded morphology and an uncommon desmin- and CD34-negative immunophenotype. A 73-year-old man underwent an excision for an 8 mm-sized breast mass. Histology revealed that the tumor was composed of fascicles of bland spindle cells showing prominent nuclear palisading and Verocay-like bodies. First, schwannoma, malignant peripheral nerve sheath tumor, and synovial sarcoma were suspected given the palisaded morphology. However, none of them was confirmed by immunohistochemical or molecular analyses. Next, a palisaded variant of myofibroblastoma was suspected by the morphology and coexpression of estrogen, progesterone and androgen receptors, BCL2 and CD10 in immunohistochemistry. However, the key diagnostic markers, desmin and CD34, were both negative. Finally, the diagnosis of myofibroblastoma was confirmed by detecting RB1 loss in immunohistochemistry and monoallelic 13q14 deletion (RB1 and FOXO1 loss) by fluorescence in situ hybridization assay. For the correct diagnosis of myofibroblastoma, it is important for pathologists to recognize the wide morphological spectrum, including a palisaded morphology, and the immunophenotypical variations, including desmin- and CD34-negative immunophenotypes, and to employ a comprehensive diagnostic analysis through combined histological, immunohistochemical and molecular evaluations.

Non-malignant fibroblastic/myofibroblastic tumors in pediatric age group: Clues and pitfalls to the cytological diagnosis.

INTRODUCTION: Fibroblastic/myofibroblastic tumors constitute 12% of all pediatric soft tissue tumors with the majority of them belonging to the benign and intermediate prognostic categories. They are often misdiagnosed owing to their variable clinical presentation and unusual microscopic features. The diagnosis, specially cytological diagnosis of benign and intermediate categories is difficult due to paucity of cellular component and increased amount of extracellular matrix as compared to malignant ones. We hereby discuss the Fine needle aspiration cytology (FNAC) findings of non-malignant fibroblastic/myofibroblastic lesion in the pediatric age group encountered at our institute. METHODS: All the benign and intermediate fibroblastic/myofibroblastic/fibroadipocytic lesions (age 0-12 years) diagnosed on FNAC over a period of 3½ years (Jan 2016- July 2019), with availability of corresponding histopathology were included in the study. RESULTS: A total of seven pediatric benign and intermediate fibroblastic/myofibroblastic lesions with histopathological confirmation were identified which included Infantile digital fibromatosis (IDF) (n = 2), Lipofibromatosis (n = 1), Fibrous hamartoma of infancy (FHI) (n = 1), Fibromatosis colli (FC) (n = 2) and myofibroma/myofibromatosis (n = 1). FNAC smears were mainly paucicellular with presence of benign spindle shaped cells in a collagenous stroma common to almost all the cases. A few additional findings such as degenerated skeletal muscle fibres, muscle giant cells and mature adipose tissue were also present in some cases. CONCLUSION: Fibroblastic/myofibroblastic tumors although uncommon, form an important category that must be considered in the differential diagnosis of pediatric soft tissue tumors. FNAC cytology features when assessed in a proper clinical setting (specially the age and site of presentation) are helpful in suggesting probable preoperative diagnosis in these lesions.

Clinicopathological and radiological characterization of myofibroblastoma of breast: A single institutional case review.

Myofibroblastoma is a rare type of benign myofibroblastic neoplasm in the breast. It is clinically presented as a well-circumscribed mass, usually small in size (usually less than 4.0 cm), and can mostly be cured by local excision. Rare cases of giant myofibroblastoma greater than 10 cm have been reported, but also follow a benign clinical course. Histologically, breast myofibroblastoma is featured by bland fascicles of spindle cells intermixed with thick hyalinized collagen bundles. Mast cells are frequently found within the stroma. However, a wide spectrum of morphological variants can occur in myofibroblatoma, making its diagnosis challenging sometimes. Differential diagnosis of myofibroblastoma with other spindle cell lesions in the breast, either benign or malignant, is also important in practice. In this study, we collected 15 cases of breast myofibroblastoma diagnosed in our institution during a 20 year period. The sizes of these cases range from 0.4 cm to 35.2 cm (mean is 3.7 cm). To our knowledge, the case of giant breast myofibroblastoma we presented here is the largest one reported to date. The histological examination of the cases show great morphological variations. Besides the classical type, features of cellular, collagenized, palisading, epithelioid, myxoid, myoid, solitary fibrous tumor-like are also identified in the case series. Immunohistochemical staining patterns as well as clinical features of the cases are also summarized and compared. All cases in this study show no recurrence on follow-up. In addition, cases that are important differential diagnosis for breast myofibroblastoma are also studied. Their key histological characteristics are compared with myofibroblastoma, and their immunohistochemical and molecular features are discussed.

Inflammatory Myofibroblastic Tumor of the Orbit in an 8-Month Old.

Inflammatory myofibroblastic tumor is a mesenchymal neoplasm, commonly seen in the lung and abdominopelvic region of children. The authors present an 8-month-old female with a 2-month history of left-sided proptosis. Examination was significant for left-sided proptosis, a left exotropia and hypotropia, left supraduction and adduction deficits, and left optic disc elevation. MRI imaging revealed an extraconal left superomedial orbital mass with globe displacement and proptosis. Left anterior orbitotomy with excisional biopsy showed a solid mass composed of an infiltrative proliferation of bland spindle cells in a variably myxoid background with associated perivascular lymphoplasmacytic infiltration. Immunohistochemistry was positive for ALK-1 and CD34 and demonstrated focal positivity for S100. Fluorescence in-situ hybridization showed an additional copy of the 3'ALK gene (46%) in interphase cells examined. Next generation targeted sequencing found a DCTN1/ALK fusion. Findings were consistent with inflammatory myofibroblastic tumor. To the authors' knowledge, this is one of the largest primary orbital inflammatory myofibroblastic tumors in the youngest reported patient.

Potential Diagnostic Pitfalls in Evaluating Immunohistochemistry for Cervical Myofibroblastomas.

Cervicovaginal myofibroblastoma (CVM) is a rare benign mesenchymal tumor of the lower female genital tract that shows chromosomal loss of 13q14 (RB1 gene located in this region). The aim of this study was to investigate the utility of immunohistochemistry (IHC) for desmin, CD34, and Rb in diagnosing CVM. All cervical polyps diagnosed from July 2016 to July 2017 were retrospectively reviewed. Cases showing morphologic myofibroblastic differentiation were evaluated by IHC for desmin, CD34, and Rb. Desmin and CD34 staining was recorded as positive or negative. Rb nuclear staining was graded as follows: 0 (<10%), 1 (10%-25%), 2 (>25%-50%), 3 (>50%-75%), or 4 (>75%). Intact nuclear expression of Rb in endothelial cells served as an internal positive control. IHC was performed on 76 cases with 14 excluded from the final cohort due to poor Rb internal control. A total of 61/62 (98.4%) cases were positive for desmin and CD34 with the following Rb distribution: grade 0 (n=53, 86.9%), grade 1 (n=5, 8.2%), grade 2 (n=2, 3.3%), and grade 3 (n=1, 1.6%). One case negative for desmin and CD34 showed grade 3 Rb staining. Upon rereview of the histology, 7/175 cases (4%) were morphologically and immunohistochemically compatible with CVM (desmin and CD34+ grade 0 Rb staining). CVM is a rare and under-recognized entity (4% of cervical polyps) for which morphology remains the mainstay of diagnosis. IHC reliance serves as a potential diagnostic pitfall as 86.9% of cases showing myofibroblastic differentiation demonstrated the staining pattern of desmin and CD34 positivity and Rb deficiency.

Practical approach to diagnosis of bland-looking spindle cell lesions of the breast.

The diagnosis of bland-looking spindle cell lesions of the breast is often challenging because there is a close morphological and immunohistochemical overlap among the different entities. The present review will discuss reactive spindle cell nodule/exuberant scar, nodular fasciitis, inflammatory pseudotumor, myofibroblastoma (classic type), lipomatous myofibroblastoma, palisaded myofibroblastoma, benign fibroblastic spindle cell tumor, spindle cell lipoma, fibroma, leiomyoma, solitary fibrous tumor, myxoma, schwannoma/neurofibroma, desmoid-type fibromatosis, dermatofibrosarcoma protuberans, low-grade fibromatosis-like spindle cell carcinoma, inflammatory myofibroblastic tumor and low-grade myofibroblastic sarcoma arising in the breast parenchyma. The pathologist should be aware of each single lesion to achieve a correct diagnosis to ensure patient a correct prognostic information and therapy. Accordingly representative illustrations and morphological/immunohistochemical diagnostic clues will be provided.

Inflammatory Myofibroblastic Tumor Driven by Novel NUMA1-ALK Fusion Responds to ALK Inhibition.

Inflammatory myofibroblastic tumors (IMTs) are soft tissue neoplasms with rare metastatic potential. Approximately half of IMTs are positive for an ALK rearrangement, and ALK inhibitors have been used successfully in the treatment of IMTs with a variety of ALK fusions. This report describes a 21-year-old woman with an aggressive, metastatic IMT with a novel NUMA1-ALK fusion that showed a dramatic response to the ALK inhibitors crizotinib and alectinib. To our knowledge, this report provides the first published description of an IMT with a NUMA1-ALK fusion. The patient's aggressive IMT responded favorably to crizotinib and alectinib, suggesting that ALK inhibitors may be effective in IMT with NUMA1-ALK fusions. We review published reports of ALK-driven IMTs that have received ALK inhibitor therapy and suggest characteristics that may be associated with favorable response to treatment. We also discuss the strengths and limitations of immunohistochemistry, fluorescence in situ hybridization, and next-generation sequencing in the diagnosis and management of IMTs.

Gastric inflammatory myofibroblastic tumor treated with combined laparoscopic and endoscopic gastric wedge resection: a case report.

BACKGROUND: Inflammatory myofibroblastic tumor is an uncommon soft tissue neoplasm rarely reported in the stomach. CASE PRESENTATION: We identified a tumor highly suggestive of poorly differentiated gastric adenocarcinoma in the lesser curvature of the stomach of a 53-year-old female during screening endoscopy. Although the patient's gastric biopsy did not reveal cancer, the tumor configuration was strongly suspicious for malignancy, and we performed a gastric wedge resection using a combined laparoscopic and endoscopic method. The lesion was diagnosed as inflammatory myofibroblastic tumor based on its morphological and immunohistological features. CONCLUSIONS: Inflammatory myofibroblastic tumor should be considered in the differential diagnosis of soft tissue tumors in the stomach. We present a case of inflammatory myofibroblastic tumor safely treated with combined laparoscopic and endoscopic gastric wedge resection.

Fibroma of the breast: a rare tumour in the spectrum of the benign spindle cell tumours of the mammary stroma.

Benign spindle cell tumours of the mammary stroma comprises different lesions that show a variable degree of fibroblastic/myofibroblastic differentiation. We herein report a previously under-recognised hypocellular fibrocollagenous tumour of the breast, for which the term "fibroma" is proposed. The tumour was composed of CD34-positive bland-looking spindle cells embedded in an abundant hyalinised stroma. Fluorescence in situ hybridisation (FISH) showed 13q14 deletion in most neoplastic cells, a chromosomal alteration typically found in mammary myofibroblastoma. Based on morphological, immunohistochemical, and cytogenetic features, we suggest that fibroma belongs to the group of the benign spindle cell tumours of the mammary stroma.

[A peculiar intra-uterine lesion: Inflammatory myofibroblastic tumor (IMT)]. / Une lésion intra-utérine atypique : tumeur myofibroblastique inflammatoire (TMI).

A 25-year-old woman presented with a spontaneous vaginal expulsion of a 4cm well-circumscribed nodule a few weeks after delivery. An inflammatory myofibroblastic tumor diagnosis was made by morphologic, immunohistochemistry and FISH analysis of the nodule.

An Obstructed Malignant Inflammatory Myofibroblastic Tumour of the Rectum.

Inflammatory myofibroblastic tumour is rare but more common in children. It shows an immunophenotypic features of myofibroblastic differentiation, hence bearing neoplastic potential. The diagnosis is challenging especially if it involves rectum. Surgical resection is the mainstay of treatment if clinically obstructed. A 65-year-old gentleman presented with intestinal obstruction, which then followed by a hartmann's procedure. Final diagnosis is a rare case of inflammatory myofibroblastic tumour of the rectum. We discuss its genetic involvement with a literature review.

Lipomatous Angiomyofibroblastoma of the Vulva: Report of a Rare Variant.

Angiomyofibroblastoma is a rare and benign tumor that usually involves vulvovaginal area in women of reproductive age and early menopause. We report a lipomatous angiomyofibroblastoma in a 55-year-old multigravid woman. This tumor measured 9 cm in size and contained prominent mature adipose tissue that comprised approximately 50% of the tumor.

Plaque-Like Myofibroblastic Tumor of Infancy: A New Case Report and Literature Review.

Plaque-like myofibroblastic tumor of infancy is a rare entity, with only a few reports described in the literature. Herein we present a new case of a nodular plaque-like lesion of the left lower back in an 18-month-old boy. The lesion might initially be thought to be a dermatofibroma, but the overall characteristics suggested the diagnosis of plaque-like myofibroblastic tumor of infancy. We also provide a summary of previous reports in the literature about this exceptional tumor.