Inflammatory Myofibroblastic Tumour in Children: A Report of Two Cases and Review of Literature.

ABSTRACT: Inflammatory myofibroblastic tumour in paediatric patients present with a diagnostic dilemma because of its clinical, radiological and histopathological features overlapping with other mesenchymal tumours common in this age. Because of its rarity, the exact features are still unclear. Here, we are reporting clinical, radiological and histopathological appearances of two such cases. In both cases, the exact diagnosis was confirmed only after immunohistochemistry. There is a need for further detailed study to exactly determine the natural course and prognosis of these tumours.

[Intranodal palisaded myofibroblastome: A rare cause of inguinal lymphadenopathy]. / Le myofibroblastome palissadique intraganglionnaire : une cause rare d'adénopathie inguinale.

INTRODUCTION: Lymphadenopathies are a major cause of consultation in internal medicine, with various causes of diagnosis. Unexplained persistent lymphadenopathy must be biopsied to rule out malignant tumor. CASE REPORT: We report the case of a 53-year-old man, with inguinal lymphadenopathy evolving for more than one year. The patient had no associated symptoms and his blood tests were unremarkable. Due to the progression of the adenopathy and its hypermetabolism on PET-CT, an excisional biopsy was performed. Histological analysis revealed an intranodal proliferation of spindle cells with a palisading pattern. ß-catenine and smooth muscle actin labelling were positive, leading to the diagnosis of intranodal palisaded myofibroblastoma, a benign tumour. CONCLUSION: Intranodal palisaded myofibroblastoma is a rare benign cause of adenopathy, with often inguinal lymph node localization and slow growth and without risk of recurrence after surgical removal.

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.

Vulval superficial myofibroblastoma with lymphocytic and eosinophilic infiltrate.

We present the case of a vulval superficial myofibroblastoma with a lymphocytic and eosinophilic rim in a woman in her late 20s. The tumour presented in pregnancy as a cystic lesion with pain and increasing size. While the histopathology of superficial myofibroblastomas has been well defined in the literature, to our knowledge, there has been no documentation of the presence of an inflammatory infiltrate of lymphocytes and eosinophils surrounding and within the tumour. This may potentially act as a diagnostic or prognostic reference.

Myofibroblastoma in the Liver: A Case Report and Review of Literature.

Myofibroblastoma is a rare benign mesenchymal tumor first described in the breast. It is also known as mammary-type myofibroblastoma outside of the breast, more frequently located along the embryonic milk line. Exceptionally, myofibroblastoma can occur at visceral locations. We present a case of myofibroblastoma detected incidentally in the liver. A well-circumscribed mass, grossly measuring 6.2 cm in the liver parenchyma, was found on imaging studies. Histologically, the lesion is characterized by benign spindle cells in a hyalinized collagenous stroma, with positive staining for SMA and ER, focal positivity for CD34, negative for desmin, and loss of RB1. This rare tumor at such an unusual location makes it diagnostically challenging, especially on core biopsy of the lesion. To our knowledge, this is the second case of myofibroblastoma in the liver reported in the English literature and the first such case with a detailed pathology description.

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.

Inflammatory myofibroblastic tumor presenting as a subepithelial lesion of the colon

We present the case of a 42-year-old male admitted to the emergency department for a 15-day history of diarrhea, with bloody stools in the past 7 days. The patient denied abdominal pain or distension as well as any constitutional symptoms. On physical examination he presented good general health condition, with abdomen slightly tender in the lower quadrants; digital rectal examination was remarkable for the presence of dark blood. Laboratory evaluation revealed new onset normocytic anemia (Hb 10.8 g/dL, MCV 89 fL) and RCP of 3.3 mg/dL. Colonoscopy was performed, which showed a large cecal subepithelial lesion, with surface ulcerations. Histology reported mixed inflammatory infiltrate but no malignancy. Further investigation was carried out with an abdominal and pelvic computerized tomography that, other than the cecal mass, showed multiple infracentimetric mesenteric lymph nodes. A right laparoscopic hemicolectomy was performed. Pathological analysis led to the unusual diagnosis of inflammatory myofibroblastic tumor (IMT) of the colon. There was no sign of recurrence after 6 months of follow-up (AU)

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.

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.

Diagnostic Challenges of Intra-operative Frozen Consultation for Mammary Epithelioid Myofibroblastoma.

Myofibroblastoma (MFB) of the breast is a rare benign neoplasm that exhibits several morphologic variants and presents diagnostic challenges for pathologists, especially in recognizing intra-operative frozen sections. In order to raise awareness of this tumor and avoid misdiagnosis, we describe a case of a 38-year-old female patient diagnosed as epithelioid MFB. This painless tumor was well-circumscribed, found in the left breast and was physically examined over a period of six months. Histologically, this tumor was predominantly composed of epithelioid cells, which arranged as single cells, small clusters or nests. Tumor stroma was collagenized with spindle cells, adipose and focal myxoid areas. This case was misinterpreted as invasive carcinoma in the frozen section. The immunohistochemical profile demonstrated positivity for Vimentin, desmin, SMA, calponin, CD34, ER, PR and AR, whereas pan-keratin, keratin 7, keratin 34ßE12, keratin 5/6, EMA, p63 and S100 were negative. RB1 was abnormally negative, confirming the diagnosis of epithelioid MFB. Making a correct diagnosis is primarily dependent on awareness by the pathologist of this unusual variant of MFB and careful integration of clinicopathologic findings to avoid potential diagnostic pitfalls.

Liver mesenchymal neoplasms: something old, something new.

Histological examination of liver biopsies and resection specimens remains the gold standard to establish a definitive diagnosis of liver lesions. While hepatocellular carcinoma remains the most commonly encountered liver lesion on mass-directed biopsies, surgical pathologists must be aware of other entities that may pose diagnostic challenges, as an accurate diagnosis is key for patient management. Mesenchymal tumours of the liver are relatively uncommon, therefore many pathologists are unfamiliar with these tumours. While the clinical presentation and radiological features of these lesions often overlap, careful attention to histological clues can assist in weeding out various congeners to arrive at the most accurate diagnosis. An additional challenge when diagnosing mesenchymal tumours is the specimen type, as mass-directed core biopsies are limited and have become standard clinical practice. Besides careful attention to histological features, radiological findings and clinical history, immunohistochemical analysis and molecular studies have become of immense diagnostic value. In this review, we discuss several common and rare mesenchymal hepatic lesions as defined in the current World Health Organization (WHO) classification and most up-to-date literature. We also discuss immunohistochemistry panels and relevant molecular findings that may assist in rendering an accurate diagnosis when encountering these lesions in daily practice.

Mammary-type Myofibroblastoma with Leiomyomatous Differentiation: A Rare Variant with Potential Pitfalls.

Myofibroblastoma is a rare, benign stromal tumor with a diverse morphologic spectrum. Mammary-type myofibroblastoma (MTMF) is the extra-mammary counterpart of this neoplasm and its occurrence throughout the body has become increasingly recognized. Similar morphologic variations of MTMF have now been described which mirror those seen in the breast. We describe a case of intra-abdominal MTMF composed of short fascicles of eosinophilic spindle cells admixed with mature adipose tissue. The spindle cells stained diffusely positive for CD34, desmin, smooth muscle actin, and h-caldesmon by immunohistochemistry. Concurrent loss of RB1 (13q14) and 13q34 loci were confirmed by fluorescence in situ hybridization whereas anchored multiplex PCR and whole transcriptome sequencing did not reveal any pathognomonic fusions suggesting an alternative diagnosis. To the best of our knowledge this is the first documented case of leiomyomatous variant of MTMF.

Intranodal Palisaded Myofibroblastoma: A Diagnostic Differential for Inguinal Lymphadenopathy.

BACKGROUND Benign tumors of the lymph nodes are rare and are not usually considered in the differential diagnosis in cases of lymphadenopathy because reactive hyperplasia, lymphoma, and metastatic carcinoma are the most likely causes of enlarged nodes. Intranodal palisaded myofibroblastoma (IPM) is a very rare benign mesenchymal tumor of the lymph nodes most often affecting but not limited to the inguinal region, with up to 92 cases reported in the English literature. The cell of origin is the intranodal differentiated smooth muscle cell or myofibroblast. Although the pathophysiology of IPM remains unclear, theories about viral oncogenesis and mutational changes in the ß-catenin gene with subsequent abnormal expression of ß-catenin and cyclin D1 have been raised. CASE REPORT We report a case of IPM in a 48-year-old man who presented with a mass in the left groin, with inconclusive imaging. The typical histologic findings of smooth muscle actin, cyclin D1, and ß-catenin positive intranodal spindle cell proliferation with characteristic palisades, amianthoid fibers, collagenous bodies, lack of atypia, and very low mitotic count, together with characteristic profile on ancillary testing, confirmed the diagnosis. In addition to staining with smooth muscle actin, cyclin D1 and ß-catenin, immunohistochemical studies showed focal positivity with desmin, a finding previously reported in 2 of the published cases. Surgical excision is usually curative, with a 6% recurrence rate and no reported cases of locally aggressive disease or malignant transformation. CONCLUSIONS Although rare, IPM should be included in the differential diagnosis of isolated lymphadenopathy.

Molecular Characterization of Inflammatory Tumors Facilitates Initiation of Effective Therapy.

Inflammatory myofibroblastic tumor (IMT) is a rare, mesenchymal tumor that has an increased incidence in childhood. Tumors are usually isolated to the chest, abdomen, and retroperitoneum, but metastatic presentations can be seen. Presenting symptoms are nonspecific and include fever, weight loss, pain, shortness of breath, and cough. Approximately 85% of IMTs harbor actionable kinase fusions. The diagnosis can be delayed because of overlapping features with inflammatory disorders, such as elevated inflammatory markers, increased immunoglobin G levels, fever, weight loss, and morphologic similarity with nonmalignant conditions. We present a girl aged 11 years with a TFG-ROS1 fusion-positive tumor of the lung that was initially diagnosed as an immunoglobin G4-related inflammatory pseudotumor. She underwent complete left-sided pneumonectomy and later recurred with widely metastatic disease. We then report the case of a boy aged 9 years with widely metastatic TFG-ROS1 fusion-positive IMT with rapid molecular diagnosis. In both children, there was an excellent response to oral targeted therapy. These cases reveal that rapid molecular testing of inflammatory tumors is not only important for diagnosis but also reveals therapeutic opportunities. Targeted inhibitors produce significant radiologic responses, enabling potentially curative treatment approaches for metastatic ROS1 fusion IMT with previously limited treatment options. Primary care pediatricians and pediatric subspecialists have a crucial role in the early consultation of a pediatric oncology center experienced in molecular diagnostics to facilitate a comprehensive evaluation for children with inflammatory tumors.

Myofibroblastoma of the male breast: A case report / Miofibroblastoma en la mama de un varón, descripción de un caso clínico

Myofibroblastoma (MFB) is a rare spindle stromal tumour of the breast that predominates in 60–80 years-old adult males. Its imaging features are nonspecific, leading to misdiagnosis. Thus, core biopsy is needed for definitive diagnosis. Macroscopically, MFB is usually a well-circumscribed, firm and rubbery, unencapsulated, pale white to grey round mass. Microscopically, it consists on spindle cells arranged in haphazardly intersecting fascicles or clusters, thick hyalinized collagen bundles and low mitotic activity with a lack of myoepithelial component and necrosis. Immunohistochemistry shows consistently positive immunoreactivity to vimentin and CD34, while expression of desmin, SMA, bcl-2 and CD99 varies. Oestrogen, progesterone and androgen receptors are usually expressed. They are constantly negative to cytokeratins, EMA, S100 protein, HMB-45 and c-kit (CD117). These differentiate them from fibroadenoma, phyllodes tumour, round pattern gynecomastia, carcinoma and sarcoma, since they present infiltrative growth and are negative to CD34. Wide local excision is curative, with no need of sentinel lymph node biopsy, since local recurrence is extremely low and has been reported to be less than 1.5%. No distant metastases have been described on the literature. We report a rare case MFB on a 73-year-old male attended at our institution presenting with a nodule on the right breast. (AU)

El miofibroblastoma (MFB) es un tumour estromal de células fusiformes que aparece en varones de 60-80 años. Las características radiológicas son inespecíficas, por lo que es necesaria la realización de biopsia para el diagnóstico definitivo. Macroscópicamente se trata de una lesión bien circunscrita, firme, no encapsulada. Microscópicamente consiste en células fusiformes organizadas en fascículos entremezclados con bandas de colágeno hialino, con baja actividad mitótica y ausencia de componente mioepitelial y necrosis. La inmunohistoquímica muestra la expresión constante de vimentina y CD34, con expresión variable de desmina, AML, bcl-2 y CD99. Los receptores de estrógenos, progesterona y andrógenos normalmente son positivos, mientras que la expresión de citoqueratinas, EMA, S100, HMB-45 y c-kit (CD117) es negativa. Estas características lo diferencian del fibroadenoma, tumour filodes, ginecomastia, carcinoma y sarcoma, ya que la mayoría de ellos se caracterizan por ser negativos para CD34 y presentar crecimiento infiltrativo. La tumorectomía es considerada curativa, sin necesidad de realizar biopsia selectiva de ganglio centinela, dado que la recurrencia local es baja (menos del 1,5%). No se ha descrito la presencia de metástasis a distancia en la literatura. Presentamos el caso de MFB en un varón de 73 años que debutó con un nódulo en la mama derecha. (AU)

Inflammatory myofibroblastic tumor: molecular landscape, targeted therapeutics, and remaining challenges.

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor of intermediate malignant potential that predominantly affects children, adolescents and young adults. IMT has a predilection for the lung, abdomen, pelvis, and retroperitoneum, however, can affect any part of the body. IMT is typically localized, and multifocal or metastatic disease is uncommon. Complete surgical resection is the treatment of choice when feasible. There is no established standard of care for unresectable and advanced IMT. Approximately half of IMTs harbor anaplastic lymphoma kinase (ALK) gene rearrangements, and fusions involving ROS1, PDGFRß, RET and NTRK have also been described. Given the molecular landscape of IMT, management of these tumors has evolved to include tyrosine kinase inhibitors and novel targeted therapeutics. This review highlights the molecular characteristics, evolution of targeted therapies and the remaining challenges in the management of IMT.

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.