1/4. Myofibroblastic tumours: neoplasias with divergent behaviour. Ultrastructural and flow cytometric analysis.myofibroblasts are spindle cells having ultrastructural features in common with smooth muscle cells and fibroblasts. In the last few years, tumours have been described in which myofibroblasts represent not only a reactive mechanism but also a true neoplastic component. They constitute new nosologic entities which might be termed "myofibroblastic tumours". Tumours with benign and, rarely, malignant behaviour are reported to belong to this group of lesions. Recently, a third tumour type with borderline biological course, named "inflammatory myofibroblastic tumour" (IMT), has been identified, a condition that has been regarded as a benign and reactive disorder for a long time. Only in recent reports has been demonstrated that, in spite of an apparently benign morphological pattern, some cases of IMT have a malignant course. In this connection, dna analysis by flow cytometry is a valuable diagnostic tool, because it allows identification of the ploidy status, a procedure that is often useful for predicting the nature and the biological behaviour of the lesion. In this study, 11 cases of myofibroblastic tumours were examined retrospectively by evaluating clinicopathological features and dna ploidy status by flow cytometry. The diagnosis of myofibroblastic tumour was confirmed by performing histology, immunohistochemistry, and electron microscopy in all patients. In detail, these 11 cases were composed of 1 benign myofibroblastoma, 1 myofibrosarcoma and 9 IMTs. Among these myofibroblastic tumours, all those with local recurrence or distant metastases (one myofibrosarcoma and three IMT) showed an aneuploid cell population demonstrable by flow cytometric analysis, whereas the other cases with benign course (one benign myofibroblastoma and six IMT) exhibited an euploid dna content. These data suggest the following: a) Besides the rare myofibroblastomas and myofibrosarcomas, IMTs represent a larger group of lesions with potentially different biological and clinical course. b) dna flow cytometric analysis is a reliable tool that support histopathological examination in characterizing those cases of IMT that, though being malignant, mimic benign lesions. Consequently, it establishes the basis for a different therapeutic approach according to the euploid or aneuploid dna content.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
2/4. Inflammatory myofibroblastic tumour of paranasal sinuses with fatal outcome: reactive lesion or tumour?Inflammatory myofibroblastic tumours (IMTs) are clinicopathologically distinctive but biologically controversial entities, which have been described in the lungs, abdomen, retroperitoneum, and extremities, but rarely affect the head and neck region. IMT usually follows a benign clinical course after radical excision, but invasive, locally recurrent, and metastatic forms of abdominal and mediastinal IMT have also been described. This report describes a case of IMT of the paranasal sinuses with a fatal outcome. A 22 year old woman was admitted to hospital as a result of epistaxis. Computed tomography scan and magnetic resonance imaging showed an expansive process in the paranasal sinuses, extending into the nasal cavity, orbita, and endocranium. The tumour progressed despite several surgical procedures. radiotherapy, corticosteroids, and chemotherapy were unsuccessful, and the patient died four years after diagnosis, as a result of extensive intracranial spread of the tumour. This is the first known case of an IMT of the head and neck region with a fatal outcome. It shows that the aggressive behaviour of IMTs is not limited to abdominal and mediastinal locations, and supports recent observations that at least a subset of IMTs represents true neoplasia rather than reactive myofibroblastic proliferation.- - - - - - - - - - ranking = 0.16666666666667keywords = behaviour (Clic here for more details about this article) |
3/4. Intra-abdominal inflammatory myofibroblastic pseudotumor: case report and review of the literature.Inflammatory myofibroblastic pseudotumors (IPM) are very rare tumor characterized by unpredictable clinical behaviour. They arise in soft tissues of almost every organ and the most common site is the lung. Over 200 cases of inflammatory myofibroblastic pseudotumor of the lung have been described in literature. Intra-abdominal IMP are very rare. We describe a case of intra-abdominal IMP in a boy of 15 years old who presented symptoms and signs of acute appendicitis. Exploratory laparotomy revealed a mass in the peritoneal cavity. The mass was removed. The histologic examination showed that it was an IMP. Surgical treatment was the only therapy. Six months after the surgical operation the patient has no sign of illness.- - - - - - - - - - ranking = 0.16666666666667keywords = behaviour (Clic here for more details about this article) |
4/4. Neural variant of fetal rhabdomyoma and naevoid basal cell carcinoma syndrome.A 15-year-old boy with the characteristic features of the naevoid basal cell carcinoma syndrome presented with a retroperitoneal mass. The tumour showed morphological features of a still ill-defined variant of fetal rhabdomyoma, characterized by well-differentiated nerve fibres admixed with immature striated muscle cells, similar to neuromuscular choristoma. Four cases of fetal rhabdomyoma and naevoid basal cell carcinoma syndrome have been previously reported. The behaviour of this tumour has been benign, although a complete excision was impossible due to its close relation with abdominal vascular trunks.- - - - - - - - - - ranking = 0.16666666666667keywords = behaviour (Clic here for more details about this article) |