Pure alveolar rhabdomyosarcoma of the uterine corpus.

Herein is presented a very rare case of alveolar rhabdomyosarcoma in the uterine corpus of a 72-year-old woman. The wall of the uterine corpus was replaced by multiple whitish-yellow, friable nodules, measuring up to 6 cm. Microscopically, the tumor was predominantly composed of round to polygonal cells arranged in an alveolar, papillary or nest pattern intermingled with multinuclear giant cells with abundant eosinophilic cytoplasm. Extensive sampling failed to show epithelial elements. Immunohistochemically, the tumor was positive for striated muscle markers such as myoglobin, myoD1 and myogenin. Metastatic lesions were found in the retroperitoneum and pelvic lymph nodes. The patient was treated by postoperative chemotherapy, but she died of systemic metastases 12 months after surgery.

Fine-needle aspiration biopsy of alveolar rhabdomyosarcoma of the parotid: a case report and review of the literature.

The cytologic features of an alveolar rhabdomyosarcoma arising within the parotid gland are described. The occurrence of this neoplasm as a primary malignancy in the parotid gland is very rare, and the tumor is usually not included in the cytologic differential diagnosis of parotid tumors. The diagnosis of the current case was achieved by a combination of fine-needle aspiration biopsy and frozen sections. Realizing the difficulty of recognizing this tumor both histologically and cytologically, we present this case to increase the awareness of this tumor's occurrence within the parotid gland and other salivary glands, and to highlight cytomorphologic features that will aid the pathologist in making the correct diagnosis.

Membrane-bound paracrystalloid structures in alveolar rhabdomyosarcoma.

We report here a case of an alveolar rhabdomyosarcoma in a 25-year-old woman. Ultrastructural examination revealed a few periodical membrane-bound crystalloids, similar to those regarded as specific for alveolar soft-part sarcoma. Our study provides evidence supporting a myogenic origin of those periodic structures, and simultaneously a myogenic origin of alveolar soft-part sarcoma.

Rhabdomyosarcoma. Morphologic, immunohistochemical, and DNA study.

In this study 80 cases of predominantly adult rhabdomyosarcoma are presented as follows: 20 cases of the embryonal type, 32 cases of the alveolar and 8 cases of the pleomorphic type. Additional histologic classification was performed in each type. In myotube stage the histologic picture of fetal muscles cannot be compared to the alveolar type of rhabdomyosarcoma. Desmin and sarcomeric actin are observed in 47.7% of all cases, and myoglobin and myosin in only 23.1%. The reactions were diffuse, disperse, or focal. Electron microscopic study subdivides desmin positive tumors into three groups of differentiation. DNA analysis shows that most desmin positive cells are diploid in comparison to all the tumor cells that are hyperdiploid and tetraploid.

Solid alveolar rhabdomyosarcoma of the hand in adolescence: a clinical, histologic, immunologic, and ultrastructural study.

Rhabdomyosarcoma (RMS), a high-grade, malignant, skeletal muscle tumor, represents approximately 5% of neoplasms in children. The poorly differentiated forms of RMS are often not easily diagnosed and classified. Among the four histologic variants, alveolar RMS is the least frequently reported subtype. A poorly differentiated solid variant of alveolar RMS occurred on the right hand of a 16-year-old girl. Because of the tumor size, local invasiveness, and occurrence of cutaneous and breast metastases at presentation, the clinical staging was group IV (T2/NO/M1). Surgical excisions of the primary and metastatic locations were performed and chemotherapy with vincristine, dactinomycin, cyclophosphamide, and doxorubicin was administered. Light and electron microscopy studies revealed a solid proliferation with a focal alveolar pattern of monomorphous, small, round neoplastic cells without easily detectable muscular morphologic features. The skeletal muscle origin was revealed by the positive immunostaining for desmin, alpha-sarcomeric actin, muscle-specific actins, and enolase, and confirmed by immunoblotting for desmin. Despite the age of our patient, which is considered by some authors an independent predictor of outcome, all prognostic variables were unfavorable. However, a disease-free interval during three years of follow-up underlines the importance of multidisciplinary regimens for the treatment of this rare solid tumor of childhood and adolescence.

Fine needle aspiration (FNA) in the diagnosis of soft tissue tumours; a review of 22 years experience.

FNA plays an important role in preoperative diagnosis of soft tissue tumours. A close clinical/morphologic cooperation is essential. FNA should be performed on the most accessible part of the tumour, avoiding penetration of the deep portions of the tumour. Needles 0.7 mm (22 G) are recommended. For deep lesions, needles with a stylet should be used. After the FNA, tattooing of the aspiration channel is recommended, and the channel is surgically removed together with the tumour, if a sarcoma. Material from the FNA can be used for additional examinations, i.e. electron microscopy, immunohistochemistry, DNA ploidy analysis and chromosomal analysis. Those techniques are of great importance in the differential diagnosis, particularly in the paediatric small/round cell tumours. The majority of sarcomas can be defined as low grade or high grade malignant in FNA. For malignancy grading the following parameters are used: cellularity, pleomorphism, chromatin pattern, nucleolar structure, mitotic figures and necroses. Cytodiagnostic details of the most common soft tissue tumours and their differential diagnoses are presented.

Rhabdomyosarcoma of the clitoris.

Genitourinary rhabdomyosarcoma in females usually originates in the vagina or uterus, but rarely the vulva. The authors present a case of rhabdomyosarcoma originating in the clitoris. A 4-year-old with an alveolar rhabdomyosarcoma of the clitoris was treated with radical clitorectomy, radiation, and chemotherapy. Follow-up at 3 years showed no active disease.

Ultrastructural characterization of poorly differentiated rhabdomyosarcomas.

Twenty-five rhabdomyosarcomas, histopathologically and immunocytochemically classified as embryonal (12 cases), alveolar (11 cases), and pleomorphic (two cases), were studied by routine and immunogold electron microscopy, to identify, in poorly differentiated cells, reproducible markers useful for diagnostic purposes. Rhabdomyoblasts with rudimentary sarcomeres were observed in 12 cases (48%). Large cells (named oval cells) with an oval shape and an eccentric nucleus, like rhabdomyoblasts but lacking organized myofilaments, were observed in 20 cases (80%). By immunogold electron microscopy, performed on four of 25 cases, both oval cells and rhabdomyoblasts showed abundant intermediate filaments positive for desmin. Oval cells may be used as markers of poorly differentiated rhabdomyosarcomas.