Alveolar rhabdomyosarcoma in a 68-year-old patient identified by cytogenetic analysis of bone marrow

Bone marrow metastasis of rhabdomyosarcoma mimicking acute leukemia: a case report and review of the literature

Bone marrow metastasis of rhabdomyosarcoma has been reported to be difficult to distinguish from acute leukemia. We herein describe a case of rhabdomyosarcoma with bone marrow metastasis mimicking acute lymphoblastic leukemia. A 29-year-old woman was admitted with thrombocytopenia, blast-like cells in the peripheral blood and a coagulation disorder. Bone marrow aspirates showed 94.8% blast-like cell infiltration (CD45(-), myeloperoxidase(-), and CD56(+)), and CT scan revealed the presence of an infiltrating mass in the nasal cavity. Based on a biopsy of the nasal cavity, the patient was diagnosed with rhabdomyosarcoma exhibiting bone marrow metastasis. She received chemotherapy, followed by radiation therapy, and has since remained alive for 26 months, as of the last follow-up.

A leukemic presentation of alveolar rhabdomyosarcoma in a 52-year-old woman without an identifiable primary tumor

A 52-year-old woman presented with fatigue and thrombocytopenia. Imaging studies were unremarkable with the exception of a positron emission tomography scan, which demonstrated intense F-18 fluorodeoxyglucose uptake fusing to the marrow. A bone marrow aspirate was notable for large discohesive cells with basophilic cytoplasm, and flow cytometric analysis identified a population of phenotypically unusual cells that coexpressed CD56 and CD71. Immunohistochemical findings in the marrow biopsy demonstrated that the neoplasm was alveolar rhabdomyosarcoma, further supported by the presence of a t(2;13). This unusual case demonstrates that leukemic presentations of rhabdomyosarcoma can occur in older adults in the absence of an identifiable primary tumor.

Soft tissue tumors of the anorectum: rare, complex and misunderstood

Anorectal soft tissue tumors are uncommon and often present both diagnostic and therapeutic challenges. Although many of these tumors are identified with imaging performed for unrelated reasons, most present with nonspecific symptoms that can lead to a delay in diagnosis. Historically, radical surgery (abdominoperineal resection) has been the mainstay of treatment for both benign and malignant anorectal soft tissue tumors. However, a lack of proven benefit in benign disease along with changes in technology has called this practice into question. In addition, the role of radiation and/or chemotherapy remains controversial. In this manuscript, we review the history and current status of anorectal soft tissue tumor management, with a particular focus on challenges in optimizing survival.

Comparing adult and pediatric rhabdomyosarcoma in the surveillance, epidemiology and end results program, 1973 to 2005: an analysis of 2,600 patients

PURPOSE

To compare clinical features and outcomes of adults and children reported to have rhabdomyosarcoma.

PATIENTS AND METHODS

We analyzed data from 1,071 adults (age > 19 years) and 1,529 children (age < or = 19 years) reported in the public-access Surveillance, Epidemiology and End Results database as having rhabdomyosarcoma, diagnosed from 1973 to 2005. Survival estimates were determined using survival time with the end point being death from any cause.

RESULTS

Adults with rhabdomyosarcoma had significantly worse outcome than children (5-year overall survival rates, 27% +/- 1.4% and 61% +/- 1.4%, respectively; P < .0001). Tumors in adults were more likely to be at an unfavorable site (65% v 55%; P < .0001) and to have histologies that are unusual during childhood, particularly the pleomorphic subtype (19%) and not otherwise specified (43%). Regional and distant spread was not more frequent in adults. Adults had significantly worse outcome than children with similar tumors. The most significant difference was in localized disease; 5-year survival estimates were 82% +/- 2.0% for children and 47% +/- 2.9% for adults (P < .0001). Multivariate analysis showed that age, histologic subtype, primary site location, stage, and local control with surgery and/or radiation were significant predictors of survival. However, alveolar subtype and unfavorable primary site lost significance when analysis was restricted to adults.

CONCLUSION

Adults reported to have rhabdomyosarcoma had worse survival than children with similar tumors. Predictors of poor outcome in children were valid in adults except for alveolar histology and unfavorable tumor site.

Alveolar rhabdomyosarcoma of the head and neck region in older adults: genetic characterization and a review of the literature

Alveolar rhabdomyosarcoma is remarkably rare in adults older than 45 years. Initial immunoprofiling of a small cell neoplasm of the head and neck region in an older adult may not include myogenic markers. A valuable diagnostic aid and important prognostic parameter in alveolar rhabdomyosarcoma is the identification of PAX3-FOXO1 [t(2;13)(q35;q14)] or PAX7-FOXO1 [t(1;13)(p36;q14)] rearrangements. The purpose of this study was to document the clinicopathologic, immunophenotypic, and genetic features of head/neck alveolar rhabdomyosarcoma in older adults. Prior isolated descriptions of 3 patients were included. Five patients were female and 2 male (median age, 61 years). Each neoplasm was composed of undifferentiated, small round cells in a predominantly solid pattern. Initially, ordered immunostains corresponded with early diagnostic impressions of a hematologic malignancy or neuroendocrine carcinoma. CD56 was positive in 5 of 5 tumors and synaptophysin in 1 of 6. Given the virtual absence of other lymphoid or epithelial markers, muscle immunostains were performed and these were positive. Definitive alveolar rhabdomyosarcoma diagnoses were confirmed genetically. This study illustrates the diagnosis of head/neck alveolar rhabdomyosarcoma in older adults is complicated by its rarity, lack of an alveolar pattern, and a potentially misleading immunoprofile (CD56 and synaptophysin immunoreactivity) if myogenic markers are not used. Both PAX3- and PAX7-FOXO1 alveolar rhabdomyosarcomas were identified in these patients. In children, PAX7-FOXO1 alveolar rhabdomyosarcoma is associated with a significantly longer event-free survival. In contrast, adult alveolar rhabdomyosarcoma behaves more aggressively with a worse overall survival than pediatric alveolar rhabdomyosarcoma. Further follow-up and additional cases are required to assess the prognostic relevance of these fusion transcripts in the context of advanced age.

Genetic diagnosis of alveolar rhabdomyosarcoma in the bone marrow of a patient without evidence of primary tumor

Alveolar rhabdomyosarcoma (ARMS) is characterized by two pathognomonic translocations, both involving the FOXO1 gene. We describe a case of a 10-year-old child with multiple lytic lesions involving all the vertebral bodies, sternum and femur and a bone marrow biopsy compatible with a small round cell neoplasia, but no evidence of a primary tumor. Interphase FISH analysis with specific probes evidenced a rearrangement involving the FOXO1 gene and RT-PCR identified the PAX7-FOXO1 fusion transcript. These data show a case of ARMS with no evidence of primary tumor presenting the PAX7-FOXO1 fusion gene.

Pediatric-type sarcomas in adult patients

Sarcomas included in the broad group of small round-cell tumors (SRCT) and some non-SRCT lesions that typically are seen in pediatric-age patients can rarely occur in adults. However, there are differences in the anatomic sites that are involved and the prognosis in these two patient groups. The diagnosis of pediatric-type sarcomas in adults is often challenging because of the unusual contextual clinical setting and morphologic features. Immunohistochemical studies have greatly facilitated this process. Moreover, limited biomolecular studies that have been conducted have demonstrated comparable cytogenetic alterations in adults and children with pediatric-type tumors. They also have raised interesting questions concerning possible biological bases for differences in clinical behavior in the two cohorts. This review focuses on the morphological, immunohistochemical, and molecular characteristics of childhood-type sarcomas that affect adults, with emphasis on possible pitfalls in differential diagnosis.

Chromosomal imbalances in pleomorphic rhabdomyosarcomas and identification of the alveolar rhabdomyosarcoma-associated PAX3-FOXO1A fusion gene in one case

Rhabdomyosarcomas (RMS) are soft tissue sarcomas resembling developing skeletal muscle, and pleomorphic rhabdomyosarcomas (PRMS) are a rare nonpediatric entity. Little molecular cytogenetic information exists for PRMS, and their relationship to other subtypes of rhabdomyosarcoma and other sarcomas is unclear. Chromosomal imbalances were determined in seven well-characterized cases of PRMS using comparative genomic hybridization. The smallest overlapping regions of gain were 1p22 approximately p33 (71%), 7p (43%), 18/18q (43%), and 20/20p (43%), and the regions of loss were 10q23 (71%), 15q21 approximately q22 (57%), 3p, 5q32 approximately qter, and 13 (all 43%). Four of the seven cases had amplicons involving the regions 1p21 approximately p31, 1q21 approximately q25, 3p12, 3q26 approximately qtel, 4q28 approximately q31, 8q21 approximately q23/8q, and 22q. These regions are distinct from those frequently associated with the alveolar subtype, whereas the embryonal subtype without anaplasia is rarely associated with amplification events other than gain/amplification of 8q material. The regions of imbalance appeared more similar to those reported for malignant fibrous histiocytomas (MFH) and osteosarcomas, consistent with the suggestion that PRMS can be considered part of the spectrum of MFH. In addition, one of the cases classified as PRMS showed evidence for the presence of a PAX3-FOXO1A fusion gene, which is characteristic of the alveolar subtype of RMS.

Rhabdomyosarcoma: cytogenetics of five cases using fine-needle aspiration samples and review of the literature

Cytogenetic analyses of fine-needle aspiration samples were performed on five cases of which three were alveolar rhabdomyosarcomas (RMS), one was embryonal RMS and one was RMS of mixed alveolar and embryonal histology. Three cases of alveolar RMS and one case of embryonal RMS showed t(2;13). A del(1)(p11) in a mixed alveolar and embryonal RMS was observed without the presence of t(2;13). add(17)(q25) was present in one of the alveolar RMS along with a t(2;13). Modal number of chromosome in the five cases ranged from hyperdiploid to hypertetraploid. Clinical, cytological, histopathological and cytogenetic findings are correlated. The role of additional abnormalities is discussed with a review of appropriate literature.

Hematologic masquerade of rhabdomyosarcoma

We present the case of a 12-year-old boy admitted with the diagnosis of acute leukemia, but found to have an infiltration of the marrow by an alveolar rhabdomyosarcoma (RMS) as determined by the cytogenetic demonstration of a t(2;13)(q25;q14). A primary tumor could not be found. With this case as a basis, we have tabulated features of all similar cases in the literature and discuss the possible optimal approaches to establishing the correct diagnosis in such patients.

Contribution of molecular genetic data to the classification of sarcomas

Many sarcomas are characterized by specific recurrent chromosomal translocations which provide powerful diagnostic tumor markers. Since 1992, the genes involved by almost all of these translocations have been cloned, inaugurating a new era in the study of sarcomas. At the biological level, these chromosomal translocations produce highly specific gene fusions, usually encoding aberrant chimeric transcription factors. Clinically, the correlation of these translocation-derived genetic markers and discrete histopathologic entities has been remarkable. Fusion gene detection has confirmed and refined the nosology of several sarcoma groups. The overall effect has been to strengthen certain pathological concepts rather than to revolutionize. The focus of this brief review is the recent impact that the cytogenetic and molecular detection of these translocations has had on sarcoma diagnosis and classification.