1/12. smooth muscle tumor of the pleura. A case report and review of the literature.Smooth muscle tumors of the serosal membranes are extremely rare and have received little attention in the literature. To the best of our knowledge, only 1 published series of 5 pleural smooth muscle neoplasms has been published to date. We describe a primary pleural neoplasm with smooth muscle differentiation documented by light microscopy, immunohistochemistry, and electron microscopy. This tumor originated in the parietal pleura in a 32-year-old white man and was diagnosed incidentally by chest radiography; the diagnosis was confirmed by magnetic resonance imaging and biopsy. Four years later, the tumor was noted to have increased in size and disseminated into the chest wall as a separate circumscribed mass located in the pectoral muscle. Both masses were resected and diagnosed as smooth muscle tumors. We conclude that smooth muscle tumor of the pleura is a well-defined entity with a low, but definite malignant potential; therefore, we recommend complete resection and long-term follow-up for all patients.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
2/12. Solitary fibroleiomyomatous hamartoma of the lung in a patient without a pre-existing smooth-muscle tumor.A solitary well-demarcated tumor was found in the left lung of a 53-year-old man. It was located in the posterior region of the lower lobe just adjacent to, but apart from, the pleura. It was resected by video-associated thoracic surgery. Macroscopically, the tumor was a whitish solid nodule without hemorrhage or necrosis, and it was 1.5 cm in diameter. Histologically, the tumor consisted of a proliferation of fibromuscular tissue in interlacing fascicles in which many tubular or cleft-like epithelial inclusions were involved. The epithelial inclusions showed cystic changes with goblet cell metaplasia in part, but no atypical changes. Other mesenchymal components such as cartilaginous, myxomatous or adipose tissues were not seen. The patient had no history of neoplasm, including smooth-muscle tumor. Thus, we diagnosed this tumor as a "true" fibroleiomyomatous hamartoma, as distinct from so-called fibroleiomyomatous hamartoma or benign metastasizing leiomyoma, which are usually found in the lungs of women who have had hysterectomies, as multiple fibromuscular nodules. We report here this rare case and we review and discuss published reports of fibromuscular tumors of the lung.- - - - - - - - - - ranking = 0.5keywords = neoplasm (Clic here for more details about this article) |
3/12. Epstein-Barr virus-associated smooth muscle tumour: a distinctive mesenchymal tumour of immunocompromised individuals.immunosuppressed patients are predisposed to the development of smooth muscle tumours which show near consistent association with Epstein-Barr virus (EBV). This report describes a 37-year-old patient with acquired immunodeficiency syndrome who initially presented with two masses in the liver. Image-guided core biopsy revealed a spindle cell tumour with histological and immunological features of smooth muscle neoplasm which was shown by in situ hybridisation for EBV early RNAs to be EBV-associated. The literature on this uncommon entity is critically reviewed and the differential diagnosis is also discussed.- - - - - - - - - - ranking = 0.5keywords = neoplasm (Clic here for more details about this article) |
4/12. Malignant perivascular epithelioid cell tumor involving the prostate.Perivascular epithelioid cell tumor (PEComa) is a neoplasm chiefly composed of HMB-45-positive epithelioid cells with clear-to-granular cytoplasm and a perivascular distribution. We describe such a tumor involving the prostate and seminal vesicle in a 46-year-old man. The tumor had characteristic histologic features of PEComa. Immunohistochemically, the tumor cells were positive for HMB-45 but negative for epithelial markers, Melan-A, and S100 protein. The tumor behaved in a malignant fashion, and the patient died of the disease 4 years after diagnosis.- - - - - - - - - - ranking = 0.5keywords = neoplasm (Clic here for more details about this article) |
5/12. Clear cell 'sugar' tumor (PEComa) of the skin: a case report.The so-called perivascular epithelioid cell neoplasm (PEComa) family includes angiomyolipoma, clear cell 'sugar' tumor (CCST), lymphangioleiomyomatosis, and clear cell myomelanocytic tumor (CCMMT). These rare tumors are characterized by the co-expression of melanocytic and muscle markers. They have been recognized in an increasing number of sites but currently only one case of PEComa, of the CCMMT subtype, has been reported in the skin in abstract form. We provide the clinicopathologic description of a case of extrapulmonary CCST located in the dermis and superficial subcutis of the thigh of a 60-year-old female. The lesion was composed of nests of epithelioid and spindle cells with abundant clear to granular cytoplasm and distinct cell borders. The tumor showed strong and diffuse immunoreactivity with HMB-45. Scattered cells expressed desmin and h-caldesmon. antibodies to S-100 protein, melan-A, cytokeratins, and smooth muscle actin were negative. This first case of cutaneous PEComa of the CCST type expands the differential diagnosis of clear cell/granular cell tumors of the skin.- - - - - - - - - - ranking = 0.5keywords = neoplasm (Clic here for more details about this article) |
6/12. Glomus coccygeum: report of a case and review of the literature.The glomus coccygeum is a vestigial structure related to the canals of Sucquet-Hoyer, an arteriovenous anastomosis surrounded by glomus cells derived from modified smooth muscle and involved in thermoregulation. It is an incidental finding in specimens from the sacral area and may represent a diagnostic challenge to the unaware observer. We present a case of a glomus coccygeum, presenting as a 1.5-mm structure adjacent to a typical pilonidal cyst excised from a 7-month-old boy, which was the subject of a second opinion consultation. The lesion showed small to medium sized clusters of predominantly epithelioid cells with moderate amounts of clear to eosinophilic cytoplasm, intercellular borders, and plump, round nuclei with fine chromatin. These cells were closely associated with small vascular channels and nerves. immunohistochemistry revealed that the epithelioid cells expressed vimentin, muscle-specific actin, neuron-specific enolase, and S-100 protein, were weakly positive for smooth muscle actin, and negative for desmin, synaptophysin, and chromogranin. The endothelial cells of the vascular channels were antibody CD31 positive. Recognition of the histologic features of glomus coccygeum is important to avoid confusion with glomus tumor and neural or smooth muscle neoplasms in the sacral area.- - - - - - - - - - ranking = 0.5keywords = neoplasm (Clic here for more details about this article) |
7/12. Report of an unusual problematic uterine smooth muscle neoplasm, emphasizing the prognostic importance of coagulative tumor cell necrosis.Follow-up data of the clinical behavior of uterine smooth muscle tumors with low malignant potential are scarce. We present a woman suffering from a uterine smooth muscle cell tumor with increased cellularity, absence of significant atypia, and two to three mitotic figures per 10 HPFs but with minimal focal coagulative tumor cell necrosis (CTCN). These microscopic features are currently accepted to label the lesion as a "smooth muscle neoplasm of low malignant potential, limited experience." After a disease-free survival of 4 years, two retroperitoneal tumors around the iliac vessels were extirpated. Both tumors consisted of smooth muscle cells with mild to moderate atypia and a mitotic index of 5-10 per 10 HPFs but with multifocal and extensive CTCN. These microscopic features were sufficient to establish the diagnosis of leiomyosarcoma. This case adds to the limited experience of the clinical behavior of problematic uterine smooth muscle cell neoplasms and underscores the prognostic importance of CTCN.- - - - - - - - - - ranking = 3keywords = neoplasm (Clic here for more details about this article) |
8/12. Dedifferentiated mixed stromal-smooth muscle tumor of the uterus. Report of a case.So-called dedifferentiation in mesenchymal neoplasms of the uterus is very rare. Among conventional low-grade stromal tumors only three cases of dedifferentiation were reported, whereas in mixed stromal-smooth muscle tumors the dedifferentiation was yet not described. Here we present such a case of low-grade mixed stromal-smooth muscle tumor with dedifferentiation. The tumor occurred in 52-years-old postmenopausal patient. The high-grade component representing a dedifferentiation showed morphology of undifferentiated sarcoma with myxoid change. The low-grade component with morphology of mixed stromal-smooth muscle tumor was limited to a few peripheral areas of the lesion. Immunohistochemically, the low-grade component showed typical positivity for CD10, estrogen receptor, progesterone receptor, and focal reactivity for myoid markers, whereas the dedifferentiated component expressed only vimentin, CD10 and estrogen receptor. This case demonstrates that low-grade mixed stromal-smooth muscle tumor of the uterus can dedifferentiate like a pure stromal tumor. It shows that extensive sampling/histological search may be needed for recognition of a minor component in a dedifferentiated tumor.- - - - - - - - - - ranking = 0.5keywords = neoplasm (Clic here for more details about this article) |
9/12. Diffuse intra-abdominal clear cell myomelanocytic tumor: report of an unusual presentation of "PEComatosis" simulating peritoneal mesothelioma.We report a case of diffuse myomelanocytic tumor of the peritoneum that simulates, clinically and instrumentally, a malignant mesothelioma. The patient was a 70-year-old woman with a history of ancient hysterectomy for fibroids, who presented with abdominal discomfort. Exploratory laparotomy revealed diffuse encasing of the peritonealized organs by a thin, fleshy, gray-white tissue rind. Scattered tumor masses were present as well. A dominant lesion measuring 6 cm in larger size was resected from the pelvis. Histological examination revealed a tumor composed of epithelioid and spindle cells, exhibiting either a clear or slightly eosinophilic cytoplasm and a mild to moderate nuclear pleomorphism. Focal areas of necrosis could be documented. Immunohistochemically, tumor cells were positive for HMB45, melan-A, and smooth muscle actin, but negative for other antibodies, including epithelial markers, desmin, and S100 protein. We believe that this case represents an example of myomelanocytic tumor of uncertain biologic potential, a member of the recently devised perivascular epithelioid cell tumors (PEComa), with an unusual presentation simulating a diffuse mesothelial neoplasm. The origin of this particular lesion is briefly discussed in light of the recent literature published on the subject.- - - - - - - - - - ranking = 0.5keywords = neoplasm (Clic here for more details about this article) |
10/12. Atypical myxoid smooth muscle tumor of the prostate: ERUS, CDI, and MR findings.Atypical myxoid smooth muscle tumor (AMSMT) of the prostate is a rare neoplasm not previously described in the radiographic literature. This report describes the unusual appearance of this tumor during endorectal ultrasound (ERUS), color Doppler imaging (CDI), and magnetic resonance imaging (MRI) in a 26-year-old man.- - - - - - - - - - ranking = 0.5keywords = neoplasm (Clic here for more details about this article) |
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