Epicatechin is a polyphenol compound that promotes skeletal muscle differentiation and counteracts the pathways that participate in the degradation of proteins. Several studies present contradictory results of treatment protocols and therapeutic effects. Therefore, the objective of this systematic review was to investigate the current literature showing the molecular mechanism and clinical protocol of epicatechin in muscle atrophy in humans, animals, and myoblast cell-line. The search was conducted in Embase, PubMed/MEDLINE, Cochrane Library, and Web of Science. The qualitative analysis demonstrated that there is a commonness of epicatechin inhibitory action in myostatin expression and atrogenes MAFbx, FOXO, and MuRF1. Epicatechin showed positive effects on follistatin and on the stimulation of factors related to the myogenic actions (MyoD, Myf5, and myogenin). Furthermore, the literature also showed that epicatechin can interfere with mitochondrias\' biosynthesis in muscle fibers, stimulation of the signaling pathways of AKT/mTOR protein production, and amelioration of skeletal musculature performance, particularly when combined with physical exercise. Epicatechin can, for these reasons, exhibit clinical applicability due to the beneficial results under conditions that negatively affect the skeletal musculature. However, there is no protocol standardization or enough clinical evidence to draw more specific conclusions on its therapeutic implementation.

Genital rhabdomyomas are extremely rare benign tumors of skeletal muscle origin, majority of them being reported in vaginal location. Extensive literature search revealed only three such cases reported in cervix. We hereby report fourth such case of cervical rhabdomyoma in a 35-years-old female patient. The diagnosis was confirmed by histomorphology with desmin and myoD1 positivity on immunohistochemistry. Due to paucity of cases no definite treatment guidelines are available. Differentiation from identical and more common malignant counterpart which is rhabdomyosarcoma is essential to avoid unnecessary aggressive therapy.

Rhabdomyosarcoma is the most common sarcoma diagnosed in childhood and adolescence, arising from the bladder/prostate in only 5%-10% of cases. Treatment-induced cytodifferention of tumor cells into mature rhabdomyoblasts has been reported following chemoradiation and is thought to suggest a more favorable outcome. We report a case of embryonal rhabdomyosarcoma of the bladder/prostate that exhibited extensive cytodifferentiation with downregulation of myogenin and MyoD1 gene expression in rhabdomyoblasts following treatment with chemoradiation therapy. The downregulation of myogenin and MyoD1 expression in rhabdomyoblasts following chemoradiation treatment has not previously been described in the literature and its significant remains uncertain.

Evidence points to the role of DNA methylation in ulcerative colitis (UC)-associated cancer (UCC), the most serious complication of ulcerative colitis. A better understanding of the etiology of UCC may facilitate the development of new therapeutic targets and help to identify biomarkers of the disease risk.
A search was performed in three databases following PRISMA protocol. DNA methylation in UCC was compared with sporadic colorectal cancer (SCRC), and individual genes differently methylated in UCC identified.
While there were some similarities in the methylation patterns of UCC compared with SCRC, generally lower levels of hypermethylation in promoter regions of individual genes was evident in UCC. Certain individual genes are, however, highly methylated in colitis-associated cancer: RUNX3, MINT1, MYOD and p16 exon1 and the promoter regions of EYA4 and ESR.
Patterns of DNA methylation differ between UCC and SCRC. Seven genes appear to be promising putative biomarkers.

Spindle cell rhabdomyosarcoma is a rare variant of embryonal rhabdomyosarcoma that has a predilection for young males and most commonly involves the paratesticular region followed by head and neck. Histopathology demonstrates elongated spindle cells with fusiform to cigar-shaped nuclei and indistinct eosinophilic cytoplasm arranged in fascicles or whorls. Although the tumor demonstrates increased cellularity and moderate atypia, the microscopic and architectural patterns can allow this tumor to be confused with multiple entities, such as leiomyosarcoma, spindle cell carcinoma, desmoplastic melanoma, or fibrosarcoma, with important therapeutic implications. Immunohistochemical workup demonstrates sarcomeric differentiation with reactivity for desmin, myogenin, and MyoD1 markers. Compared with other subtypes, the spindle cell variant in children is associated with a favorable outcome; however, in the adult population there does not appear to be any prognostic advantage.

BACKGROUND: Rhabdomyosarcoma is a malignant mesenchymal tumor with skeletal muscle differentiation. Primary cutaneous rhabdomyosarcoma is rare. We report a series of 11 cases of primary cutaneous rhabdomyosarcoma.
METHODS: Cases diagnosed as rhabdomyosarcoma arising in the dermis/subcutis with no identified primary tumor elsewhere were retrospectively reviewed. Follow-up was obtained.
RESULTS: The tumors occurred in five children and six adults. The adult subset consisted of pleomorphic, epithelioid and not otherwise specified (NOS) subtypes while the pediatric subset showed alveolar and embryonal subtypes. All cases showed immunohistochemical staining consistent with the diagnosis of rhabdomyosarcoma. Three adult cases showed immunoreactivity for cytokeratins (one pleomorphic, one epithelioid and one NOS.
CONCLUSIONS: Primary cutaneous rhabdomyosarcoma shows a bimodal age distribution and male predominance, correlating with rhabdomyosarcoma in deep soft tissue. Follow-up, available on all patients, showed aggressive behavior in both children and adults. Primary cutaneous rhabdomyosarcoma should be considered in the differential diagnosis of tumors with abundant eosinophilic cytoplasm and those with \"small round blue cell\" morphology. Desmin, myogenin and MYOD1 are a trio of markers with high sensitivity and specificity for primary cutaneous rhabdomyosarcoma. Cytokeratin immunoreactivity in primary cutaneous rhabdomyosarcoma represents a potential diagnostic pitfall in the differential diagnosis with sarcomatoid carcinoma.

Sclerosing spindle cell rhabdomyosarcoma (SSRMS) is a newly recognized entity in adults. The authors report a new case of SSRMS in a 31-year-old woman who presented with a large right leg mass. Biopsy revealed a malignant spindle cell neoplasm with focal sclerotic areas. A diagnosis of monophasic synovial sarcoma was favored initially. The tumor cells in the resection specimen were positive for myosin, myogenin, and MyoD1. Fluorescence in situ hybridization performed on the resection specimen showed no evidence of SYT gene rearrangement in the neoplastic cells, ruling out monophasic synovial sarcoma. A diagnosis of SSRMS was established. The patient succumbed to widely metastatic disease 16 months after initial diagnosis. This case highlights the utility of skeletal muscle markers and cytogenetic testing in distinguishing SSRMS from its mimic, monophasic synovial sarcoma. It is hoped that this case will expand the literature on adult SSRMS and help clinicians and pathologists better understand this newly described entity.

OBJECTIVE: To study the clinicopathologic characteristics of sclerosing rhabdomyosarcoma (SRMS) and its distinction from embryonal rhabdomyosarcoma (ERMS) and alveolar rhabdomyosarcoma (ARMS).
METHODS: The clinical, histologic and immunohistochemical features of 4 cases of SRMS were studied. The literature was reviewed.
RESULTS: All the 4 cases occurred in adults. The age of patients ranged from 20 to 54 years (mean = 41.5 years). The male-to-female ratio was 1:1. The tumor was located in the left wrist, right thigh, right face and right cheek respectively and the tumor size varied from 2.5 cm to 10 cm in dimension (mean = 5.7 cm). Histologically, SRMS was characterized by the presence of large amounts of heavily hyalinized matrix, mimicking osteoid or chondroid tissue. The tumor cells were composed predominantly of primitive small round cells which were arranged in diverse growth patterns, including fascicular, cord-like, single-file, trabecular, microalveolar and pseudovascular structures. A few rhabdomyoblasts were identified in 1 case. A second spindle cell component was focally found in 2 cases, resembling spindle cell rhabdomyosarcoma or peripheral nerve sheath tumor. Immunohistochemically, all cases showed diffuse staining for Myo D1 and focal staining for desmin. The staining for myogenin was often negative. Three of the cases also expressed muscle-specific actin and 2 cases were positive for alpha-smooth muscle actin. They were all negative for h-caldesmon, S-100 protein, CD31, CD34, AE1/AE3 and anaplastic lymphoma kinase protein.
CONCLUSIONS: SRMS differs from ERMS and ARMS morphologically. Recent cytogenetic studies however suggest a histogenetic relationship with ERMS. Familiarity with its morphologic features and immunophenotype may help to distinguish this peculiar variant of rhabdomyosarcoma from a variety of lesions with abundant sclerosing matrix.

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Rhabdomyosarcoma is the most common soft tissue malignancy in children but is rare in adults. The latest World Health Organization classification of soft tissue tumors recognizes embryonal, alveolar, and pleomorphic rhabdomyosarcomas. More recently, a sclerosing variant of rhabdomyosarcoma has been recognized and reported in seven adult patients. We describe a pediatric case of sclerosing rhabdomyosarcoma presenting as a sacral mass in a 3-year-old girl. Morphologically, the tumor showed a prominent sclerosing hyaline matrix and demonstrated pseudovascular and microalveolar architectural foci. Focal positivity was seen with desmin, smooth muscle actin, and myogenin. MyoD1 showed uniform diffuse nuclear staining. Fusion transcripts were not demonstrated by reverse transcriptase-polymerase chain reaction analysis. The histology, immunohistochemistry, and molecular genetics matched those reported in the seven adult cases of sclerosing rhabdomyosarcoma. This is the first case report, to our knowledge, of this rare tumor arising in the pediatric age group, and we compare the features with those reported in adult sclerosing rhabdomyosarcoma.