Muscle-specific Actin (muscle-specific + actin)

Distribution by Scientific Domains


Selected Abstracts


Histopathological characterization of aortic intimal sarcoma with multiple tumor emboli

PATHOLOGY INTERNATIONAL, Issue 11 2000
Naoki Nishida
A case of aortic intimal sarcoma with multiple tumor emboli and distal metastasis is reported. All metastasis (adrenal, spleen) were via the arteries. This case also had independent lung cancer. Macroscopically, the aortic tumor did not form a bulged mass, but had linear ulceration with abundant mural thrombi. Poorly cohesive large atypical cells were seen in the intima of the abdominal aorta without invasion into the media. Tumor cells were disseminated into the mural thrombi on the aorta and embolized its branches. In the metastatic tumor or tumor emboli of the distal artery, there were not only large atypical cells, but also the foci of spindle-shaped cells or epithelioid differentiation. Tumor cells in the aorta were immunohistochemically positive for only vimentin. Muscle-specific actin was positive focally for spindle-shaped cells of tumor emboli and metastatic tumors. Furthermore, cytokeratin-positive cells were scatteredly seen. All tumor cells were negative for factor VIII and did not have a histologic or phenotypic analogy with lung cancer. The primary intimal sarcoma in the present case was of undifferentiated non-endothelial intimal stromal cell origin, and may have had multipotential for differentiation. Investigation of the metastatic site was useful for recognizing the features of this tumor. [source]


Myofibroblastic differentiation in malignant fibrous histiocytoma (pleomorphic myofibrosarcoma): a clinicopathological study

HISTOPATHOLOGY, Issue 6 2001
E Montgomery
Myofibroblastic differentiation in malignant fibrous histiocytoma (pleomorphic myofibrosarcoma): a clinicopathological study Aims:,We compared the clinical and pathological features of pleomorphic malignant fibrous histiocytoma (MFH)-like soft tissue sarcomas with and without myofibroblastic differentiation on electron microscopy. Methods and Results:,Fifty-three soft tissue tumours designated as MFH by light and electron microscopy were reassessed. Eighteen were specifically diagnosed and excluded, and follow-up (FU) information obtained for 24 of the other 35 cases. Myofibroblastic ultrastructure was seen in 7/24 (29%). Seventeen of 24 (71%) lacked myofibroblasts on electron microscopy, which showed fibroblastic or undifferentiated cells. Histologically, all tumours but one had storiform-pleomorphic areas; one myofibroblastic neoplasm was fascicular and myxoid. No other morphological differences were seen. In seven myofibroblastic cases, smooth muscle in four cases and muscle-specific actin in two cases, desmin in three cases and S100 in one case were present. In 15 other tumours, smooth muscle in five cases and muscle-specific actin in one case, and desmin in one case were present; none of these cases expressed S100. CD34 was found in the myxoid areas of one myofibrosarcoma and 3/15 other tumours. Positivity for bcl-2 was seen only in non-myofibroblastic sarcomas (4/14). On follow-up (median 41 months), 2/7 (29%) myofibroblastic tumours recurred, 5/7 (71%) metastasized, and 3/7 (43%) patients died of disease. Among the non-myofibroblastic sarcomas, with a median follow-up of 47 months, 6/17 cases (35%) recurred, 10/17 (59%) metastasized, and 7/17 patients (41%) died of disease. Conclusions:,Pleomorphic sarcomas with and without myofibroblastic differentiation on electron microscopy are clinically and histologically similar. The former display myoid immunohistochemical markers more frequently. [source]


Skeletal muscle regeneration: report of a case presenting as a cutaneous nodule following blunt trauma to the lip

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 4 2007
Samer H. Ghosn
A 61-year-old man presented with a 4-month history of an enlarging nodule on the upper lip following blunt trauma. An initial punch biopsy was non-diagnostic. A deeper biopsy revealed a multilobular proliferation of atypical and pleomorphic cells with vesicular nuclei, prominent nucleoli, and large amphophilic cytoplasm. Immunoperoxidase studies showed these cells to be positive for muscle-specific actin and desmin and negative for S-100 protein and smooth muscle actin. Based on these findings, a diagnosis of skeletal muscle regeneration (SMR) was made. To our knowledge, this is the first report of SMR presenting clinically as a rapidly growing cutaneous nodule on the lip following blunt trauma. [source]


Cutaneous mesenchymal hamartoma with mixed myogenous differentiation

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 4 2006
John Edwin Schrecengost
A 3-month-old infant girl presented with a polypoid lesion in the perianal region. No changes in this lesion had been noted since birth. Microscopic examination of the excised specimen showed a mixture of mesenchymal elements, dominated by haphazard thin fascicles of skeletal muscle. Collagen and vascular changes were also apparent. Immunohistochemistry showed positive staining for muscle-specific actin and desmin in the fascicular components of the lesion, and smooth muscle actin, desmin, and h-caldesmon positivity in a haphazard collection of muscle fibers in the deep dermis and anal submucosa. Numerous Verhoeff-van Gieson positive elastic fibers were also noted. Hamartomas containing skeletal muscle have rarely been reported outside of the head and neck region. They must be distinguished from a variety of other tumors, including juvenile rhabdomyoma, benign Triton tumor, and rhabdomyosarcoma. [source]


Glomus Coccygeum: Report of a Case

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005
A. Rahemtullah
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, that 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 histological features of glomus coccygeum is important to avoid confusion with glomus tumor and neural or smooth muscle neoplasms in the sacral area. [source]


Pyogenic granuloma of the oral cavity: Comparative study of its clinicopathological and immunohistochemical features

PATHOLOGY INTERNATIONAL, Issue 7 2005
Apostolos Epivatianos
There are two histological types of pyogenic granuloma (PG) of the oral cavity: the lobular capillary hemangioma (LCH) and non-LCH type. The aim of the present study was to examine and compare the clinical features, etiological factors, diameter of vascular elements and immunohistochemical features of LCH and non-LCH histological types of PG to determine whether they are two distinct entities. Thirty cases of LCH and 26 cases of non-LCH PG were retrieved and retrospectively studied. Clinically, LCH PG occurred more frequently (66.4%) as sessile lesion whereas non-LCH PG occurred as pedunculated (77%). Non-LCH PG was associated more frequently (86.4%) with etiological factors. The lobular area of the LCH PG contained a greater number of blood vessels with small luminal diameter than did the central area of non-LCH PG. In the central area of non-LCH PG a significantly greater number of vessels with perivascular mesenchymal cells non-reactive for ,-smooth muscle actin and muscle-specific actin was present than in the lobular area of LCH PG. The differences found in the present study suggest that the two histological types of PG represent distinct entities. [source]


Collagenous fibroma (desmoplastic fibroblastoma) of the finger in a child

PATHOLOGY INTERNATIONAL, Issue 4 2002
Jun Nishio
Collagenous fibroma (desmoplastic fibroblastoma) is a distinctive benign fibrous soft tissue tumor that typically occurs in the subcutaneous tissue or skeletal muscle in adults. We describe a case of collagenous fibroma in a 7-year-old boy who presented with a 1-cm solitary, firm nodule on the volar aspect of the metacarpophalangeal joint of the left little finger. Microscopically, the tumor was composed of spindle- and stellate-shaped cells embedded in a hypovascular, densely collagenous stroma. No mitotic figures, calcifications or necrosis were identified. Immunohistochemically, tumor cells were diffusely positive for vimentin, but negative for smooth muscle actin, muscle-specific actin, desmin, cytokeratin, S-100 protein or CD34. To our knowledge, this is the second reported case of collagenous fibroma in children. Our case report indicates that the clinicopathological features of collagenous fibroma in childhood are similar to those in adults. [source]


Primary osteosarcoma of the uterine corpus: Case report and review of the literature

PATHOLOGY INTERNATIONAL, Issue 2 2002
Mu Su
A rare case of rapidly growing osteosarcoma that developed in the uterine corpus of a 62-year-old woman is presented. The tumor occupied almost the entire pelvic cavity and extended into the abdominal cavity, with marked involvement of the intestines. Histopathologically, the tumor was composed of an osteoblastic component, accompanied by conspicuous bone formation, and a fibroblastic component. The tumor cells were positive for vimentin and osteocalcin, as well as desmin, ,-smooth muscle actin and muscle-specific actin, but negative for h-caldesmon. The results indicated myofibroblastic differentiation in a part of the tumor. A review of 14 reported cases and our case of uterine osteosarcoma revealed that this tumor has a biologically aggressive nature, although its histopathological and immunohistochemical features are similar to those of osteosarcomas in soft tissue and bone. As the prognosis of patients with this tumor is poor, it is of importance to differentiate this tumor from other types of tumors arising from the uterine corpus. [source]


Primary hepatic clear cell myomelanocytic tumor,

APMIS, Issue 12 2007
Case report, review of the literature
A case of hepatic clear cell myomelanocytic tumor in a 31-year-old woman presenting clinically with abdominal pain is reported. Histopathologic examination showed a lesion characterized by a population of large epithelioid cells with clear or eosinophilic granular cytoplasm, rich in glycogen. Immunohistochemically, the tumor cells were positive for HMB-45, Melan-A and muscle-specific actin, but negative for epithelial markers, desmin, S-100 protein, and neuroendocrine markers. Ultrastructurally, the tumor cells had abundant glycogen, well-developed rough endoplasmic reticulum, microtubules and aberrant melanosomes. Clinical and pathologic features with a brief review of the relevant literature for hepatic CCMMT as a variant of perivascular epithelioid cell tumor (PEComa) are discussed. [source]


Cluster analysis of immunohistochemical markers in leiomyosarcoma delineates specific anatomic and gender subgroups

CANCER, Issue 18 2009
Jason C. Carvalho MD
Abstract BACKGROUND: Leiomyosarcoma (LMS) can be categorized into uterine, retroperitoneal, nonretroperitoneal soft tissue, cutaneous, visceral, and osseous anatomic subtypes. The differential expression of smooth muscle markers, estrogen receptor (ER), progesterone receptor (PR), and Wilms tumor-1 protein (WT1) by anatomic subtype and gender was explored. METHODS: A total of 78 LMS comprised of 30 uterine and 48 nonuterine tumors were studied. Nonuterine tumors were comprised of 17 soft tissue, 16 retroperitoneal, 7 cutaneous, 5 visceral, and 3 osseous subtypes. Immunohistochemical staining intensity on tissue microarray slides was scored as 0, 1+, or 2+, and cluster analysis was performed on the data. RESULTS: Smooth muscle actin was the most sensitive antibody (95%), followed by muscle-specific actin (91%), calponin (88%), desmin (73%), caldesmon (66%), and myosin (64%). Caldesmon and myosin were usually coexpressed, and were highest in retroperitoneal tumors (94%). There was no discernable correlation noted between histologic differentiation and smooth muscle marker expression. ER was much more common in women, with the highest frequencies noted in female retroperitoneal (86%) and uterine (63%) tumors. Nuclear WT1 was expressed in 11% of all tumors, and was limited to ER-positive uterine and female retroperitoneal tumors. Cluster analysis segregated 4 groups, most notably 1 driven by ER and PR, with the vast majority being uterine and female retroperitoneal tumors. CONCLUSIONS: Smooth muscle markers demonstrated variable sensitivities in LMS, with a tendency for anatomic subtypes to segregate based on expression patterns of these markers. ER defined a subgroup of uterine and female retroperitoneal tumors, and WT1 was limited to such tumors, suggesting a common line of differentiation as well as potential therapeutic targets. Cancer 2009. © 2009 American Cancer Society. [source]


Myoid differentiation and prognosis in adult pleomorphic sarcomas of the extremity

CANCER, Issue 4 2003
An analysis of 92 cases
Abstract BACKGROUND The results of a recent study demonstrated an association between myoid differentiation and an adverse prognosis in adult patients with pleomorphic sarcoma, as determined by 5-year metastasis-free survival rates. METHODS To confirm the importance of muscle differentiation on prognosis in a well controlled clinical context, 92 samples from patients with pleomorphic sarcoma of the extremity from a single institution were immunostained with 4 monoclonal antibodies believed to be correlated with myoid differentiation: ,-smooth muscle actin, muscle-specific actin, desmin, and myoglobin. RESULTS Forty-two cases were positive for at least 1 muscle marker and 50 cases were uniformly negative. Between the two groups, there was no significant difference in tumor size, tumor extent, or patient age found; however, histologic grade was significantly higher (P = 0.038) in the myoid tumors. The 5-year survival differed significantly between patients with myoid tumors (35%) and those without myoid tumors (65%) (P = 0.0054). Myoid differentiation remained an adverse prognostic indicator after adjusting for clinically significant factors (i.e., histologic grade, tumor size, tumor extent, and patient age) (P = 0.01) (hazard ratio, 2.39; 95% confidence interval, 1.24,4.63). Furthermore, there was an inverse relation found between the number of myoid markers present and survival (P = 0.004). CONCLUSIONS Myoid differentiation was found to be an independent indicator of adverse prognosis in adult patients with pleomorphic spindle cell sarcoma of the extremity. Cancer 2003;98:805,13. © 2003 American Cancer Society. DOI 10.1002/cncr.11617 [source]