Benign female genital tract smooth muscle tumors with adipocytic differentiation: A morphologic, immunohistochemical and MDM2 fluorescence in situ hybridization study of 44 conventional lipoleiomyomas and lipoleiomyoma variants

Leiomyomas with adipocytic differentiation typically occur in the uterus although they may arise at several sites in the female genital tract. While these are most commonly spindled leiomyomas with a component of adipocytic tissue ("conventional lipoleiomyomas"), there is a relatively ill-defined assortment of leiomyoma variants with adipocytic differentiation. We performed a morphologic, immunohistochemical and MDM2 gene amplification analysis of a large series of gynecologic leiomyomas with adipocytic differentiation to better define the clinicopathologic spectrum. Forty four tumors from 44 patients were identified and classified as conventional lipoleiomyoma (n = 21), adipocyte-rich lipoleiomyoma (defined as tumor volume >80 % adipocytes, n = 9); cellular lipoleiomyoma (n = 9); hydropic lipoleiomyoma (n = 3); and lipoleiomyoma with bizarre nuclei (n = 2). Patient age ranged from 32 to 83 years (mean 63; median 63). Primary location included uterine corpus (35), uterine cervix (3), uterine corpus/cervix (1), broad ligament (2), parametrium (2), and round ligament (1). Tumor size was 0.6-30 cm (mean 8; median 6). None of the 34 patients with follow up developed further disease (range 1-311 months; mean 65; median 41). Immunohistochemical expression of ER, PR, HMB45, Melan A, Cathepsin K and WT-1 in lipoleiomyomas and variants was similar to patterns in non-adipocytic gynecologic leiomyomas. MDM2 amplification fluorescence in situ hybridization performed on 14 tumors was negative in all. Our findings suggest female genital tract conventional lipoleiomyomas and lipoleiomyoma variants largely parallel their non-adipocytic counterparts in morphology and immunophenotype, and may be categorized using non-adipocytic leiomyoma histologic criteria.

Primary thyroid smooth muscle tumour

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Update on Mesenchymal Lesions of the Lower Female Genital Tract

This article provides an update of the recent developments in mesenchymal tumors of lower genital tract. We focus on the characterization of recurrent molecular events in certain genital stromal tumors, for instance angiomyofibroblastomas and superficial myofibroblastomas. Moreover, fusions involving Tyrosine-kinases receptors (NTRK, FRFR1, RET, COL1A1-PDGFB) have been demonstrated in an emerging group of mesenchymal tumors characterized by a fibrosarcoma-like morphology and a predilection for uterine cervix of premenopausal women. We also cover the topic of smooth muscle tumors of the lower genital tract, which can be now classified using the same diagnostic criteria than their uterine counterpart..

When the uterine mass is not a leiomyoma

A 37-year-old nulliparous woman with abnormal uterine bleeding and a uterine mass suggestive of a leiomyoma not responding to medical therapy was submitted to two hysteroscopies with histological analysis. The first one showed a 'leiomyoma' and the second a 'uterine smooth muscle tumour of uncertain malignant potential/epithelioid leiomyosarcoma, with positivity for hormonal receptors'. The patient was submitted to a total hysterectomy with bilateral salpingo-oophorectomy, and the microscopic examination of the tumour revealed a 'uterine tumour resembling ovarian sex-cord tumours'. According to the literature, most cases are diagnosed in postmenopausal women and have a favourable prognosis. These rare tumours have uncertain malignant potential and have no established treatment protocol, but it appears that a fertility-sparing approach is possible once they are well diagnosed.

HISTOPATHOLOGICAL, PROLIFERATIVE, APOPTOTIC AND HORMONAL CHARACTERISTICS OF VARIOUS TYPES OF LEIOMYOMAS

Uterine leiomyomas decrease the quality of life by causing significant morbidity among women of reproductive age. Histologically various types of leiomyoma's can be differentiated. We have analysed the histopathological, proliferation, apoptotic and hormonal profile in different types of leiomyomas. Study included altogether 140 cases distributed into following groups: group I - normal myometrium (20 cases), group II-classic leiomyoma (69 cases), group III-cellular leiomyoma (15 cases), group IV - bizarre cell/atypical leiomyoma (22 cases), group V - smooth muscle tumors of uncertain malignancy potential (STUMP) (8 cases) and group VI - leiomyosarcoma (6 cases). Together with classic histopathological features such as nuclear atypia, cellularity, presence of mitoses, vasculature and necrosis, immunohistochemical phenotype using antibodies against Ki67, Cas3, ER and PR were analysed. The results of our study showed that leiomyomas are characterised with variable histopathological and immunohistochemical phenotype. Especially, two entities, bizzare/atypical leiomyoma and STUMP, which can be divided into two subgroups according to the presence of the degree of atypia and the expression of proliferation, apoptosis and hormonal markers, which might be the explanation of their different prognosis. Presented histopathological and immunohistochemical features should be considered in the diagnosis of myometrial smooth muscle tumors.

Recent observations on mesenchymal tumours in adults and children

Recognition of the types and characteristics of mesenchymal tumours is important, since each type has biological features peculiar to itself that govern its growth and behaviour and it is essential to know these if treatment is to be effectual. Because many differentiated cell types are capable of acting as facultative fibroblasts, histological diagnosis is often in error. It has been found that no matter how bizarre a tumour may appear, if explanted in vitro, the cells will betray their true nature. By this means the various mesenchymal tumour types have been classified, many examples collected and followed up and their biological potentialities recorded. In more recent studies these uncommon tumours in children have been studied and many of them found to be less malignant than in adults. New varieties of mesenchymal tumours have been discovered in recent years, such as pseudosarcomatous fasciitis, elastofibroma dorsi, and bizarre variants of smooth muscle tumour.

Smooth muscle tumors of the alimentary canal

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Smooth muscle tumors of the stomach: a presentation of eleven cases

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