Late dental and bone alterations in patients after orbital rhabdomyosarcoma treatment.

PURPOSE: Orbital rhabdomyosarcoma is a rare soft tissue sarcoma in childhood but with a good prognosis. Treatment usually includes surgery, chemotherapy, and radiotherapy. This study aimed to evaluate long-term alterations in teeth and cranial bones in children, adolescents, and young adults after oncologic treatment for childhood orbital rhabdomyosarcoma. METHOD: This was a cross-sectional study that evaluated patients treated for orbital rhabdomyosarcoma between 1988 and 2011. Demographic, clinical, and treatment data were collected during the study period; also, panoramic radiographs, cephalometric study, and photographs of the face were taken. RESULTS: Eight long-term survivors were studied. Of those, 50% were male, 75% had less than 5 years of treatment, and 88% had only one of the orbits affected by the tumor. Regarding treatment, 50% received 50.4 Gy of radiotherapy in the orbit; the chemotherapy included vincristine, actinomycin D, and cyclophosphamide in 75% of the cases and also ifosfamide and etoposide in 25%. The children presented craniofacial alterations, mainly when radiotherapy occurred between 0 and 5 years old (p = 0.01). The mandibles also showed dental alterations, probably due to chemotherapy. CONCLUSION: In conclusion, orbital RMS patients treated with chemoradiotherapy, important dental, and facial bone alterations were found. The most significant were in the maxilla and close to the irradiation field. Dental and mandibular bone alterations were also found, indicating the probable chemotherapy action, as this region was not included in the irradiation field.

Systemic sequelae and craniofacial development in survivors of pediatric rhabdomyosarcoma.

INTRODUCTION: The aim of this study was to evaluate the systemic sequelae, as well as the dental and craniofacial development, of patients with rhabdomyosarcoma in relation to the treatment received and clinical-pathological variables. MATERIALS AND METHODS: A retrospective cross-sectional study was performed. All individuals diagnosed with RMS between 1990 and 2022 were considered eligible. Cases who survived the primary tumor were included. Data were collected from medical records, and patients were called for clinical and radiographic examinations. RESULTS: Thirty-eight patients were assessed, with a mean disease-free survival of 216.68 months (±84.99). The primary location of the tumor was mainly the head and neck region (57.9 %). All patients received chemotherapy, and 30 (78.9 %) also underwent radiotherapy. The most frequently observed sequela was sensory impairment, which was significantly associated with tumors in the head and neck (p < 0.05), as well as with the use of radiotherapy (p = 0.034). Root formation failure was observed in 60 % of cases, microdontia in 50 %, and delayed tooth eruption in 40 %. A convex profile was predominant (80 %), along with maxillary (50 %) and mandibular (80 %) retrusion and a skeletal class II diagnosis (60 %). CONCLUSIONS: Late systemic, dental, and craniofacial developmental sequelae are observed in pediatric rhabdomyosarcoma survivors, especially in patients who underwent radiotherapy in the head and neck region. Younger individuals at the time of treatment are at greater risk of late sequelae.

Mimicry of Rhabdomyosarcoma by Tonsillar Actinomycosis: Case Report.

Actinomycosis is a rare infectious disease characterized by slowly progressive, chronic suppurative lesions, often mistaken for malignancies due to its ability to mimic them. It is caused by Actinomyces bacteria, which are part of the normal flora of the human oropharynx, gastrointestinal, and urogenital tracts. This case report describes a 51-year-old male with a history of mandibular rhabdomyosarcoma presenting with severe shoulder and hip pain, dysphagia, and headaches, initially suspected to be a cancer recurrence. However, after further investigation, including a PET-CT and tonsillectomy, the diagnosis of actinomycosis was confirmed through histopathological examination. The case highlights the diagnostic challenges of actinomycosis, especially in patients with complex clinical histories, emphasizing the importance of considering it as a differential diagnosis in similar presentations. The patient was treated with long-term antibiotic therapy, predominantly beta-lactams, demonstrating the necessity of a comprehensive diagnostic approach and the implications of a delayed diagnosis. This case underscores the critical need for high clinical suspicion and awareness among healthcare professionals regarding the potential for actinomycosis to mimic more common diseases, ensuring timely and accurate treatment.

Acetylated galactopyranosyl N-heterocyclic monocarbene complexes of Silver(I) as novel anti-proliferative agents in a rhabdomyosarcoma cell line.

Herein, four silver(I) complexes bearing acetylated d-galactopyranoside-based N-heterocyclic carbene ligands were synthesized and fully characterized by elemental analysis, NMR, and X-ray photoelectron spectroscopy. All complexes were obtained with an anomeric ß-configuration and as monocarbene species. In this study, we investigated the biological effects of the silver(I) complexes 2a-d on the human rhabdomyosarcoma cell line, RD. Our results show concentration-dependent effects on cell density, growth inhibition, and activation of key signaling pathways such as Akt 1/2, ERK 1/2, and p38-MAPK, indicating their potential as anticancer agents. Notably, at 35.5 µM, the complexes induced mitochondrial network disruption, as observed with 2b and 2c, whereas with 2a, this disruption was accompanied by nuclear content release. These results provide insight into the utility of carbohydrate incorporated NHC complexes of silver(I) as new agents in cancer therapy.

Rhabdomyosarcoma Associated with Core Myopathy/Malignant Hyperthermia: Combined Effect of Germline Variants in RYR1 and ASPSCR1 May Play a Role.

Rhabdomyosarcomas have been described in association with thyroid disease, dermatomyositis, Duchenne muscular dystrophy, and in muscular dystrophy models but not in patients with ryanodine receptor-1 gene (RYR1) pathogenic variants. We described here an 18-year-old male who reported a cervical nodule. Magnetic resonance images revealed a mass in the ethmoidal sinus corresponding to rhabdomyosarcoma. As his father died from malignant hyperthermia (MH), an in vitro contracture test was conducted and was positive for MH susceptibility. Muscle histopathological analysis in the biopsy showed the presence of cores. Molecular analysis using NGS sequencing identified germline variants in the RYR1 and ASPSCR1 (alveolar soft part sarcoma) genes. This report expands the spectrum of diseases associated with rhabdomyosarcomas and a possible differential diagnosis of soft tissue tumors in patients with RYR1 variants.

Clinical-pathologic profile of head and neck rhabdomyosarcoma in children: a systematic review.

This systematic review aimed to analyze the clinicopathological profile and relevant prognostic factors of head and neck rhabdomyosarcoma in pediatric patients. The search was carried out in the electronic search portals PubMed, Lilacs, Embase, Scopus, and Web of Science. The search yielded studies that were then analyzed regarding study topic, data extraction, and risk of bias using the STROBE (Strengthening the Reporting of Observational Studies) guidelines. Finally, three studies were included for qualitative analysis. Most of the cases involved embryonic and alveolar rhabdomyosarcoma. Expression of MYOD1 was highly correlated with diagnosis of spindle cell/sclerosing rhabdomyosarcoma, which appears to have a poor prognosis in children. Furthermore, tumor size <5 cm and absence of metastasis accompanied by complete resection and administration of adjuvant therapies such as chemotherapy and radiotherapy favored a better prognosis.

Soft-Tissue Anaplastic Lymphoma Kinase-Positive Anaplastic Large Cell Lymphoma in a Child Unmasked by COVID-19.

Anaplastic large cell lymphoma (ALCL) is children's most common mature T-cell neoplasm. The majority is positive for anaplastic lymphoma kinase (ALK). Initial presentation as a soft-tissue pelvic mass without nodal involvement is rare and can be easily misdiagnosed. We report a case of a 12-year-old male presenting with pain and movement restriction in the right extremity. Computed tomography (CT) scan revealed a solitary pelvic mass. Initial biopsy examination concluded rhabdomyosarcoma. After developing pediatric multisystemic inflammatory syndrome due to coronavirus disease 2019 (COVID-19), central and peripheral lymph node enlargement appeared. New cervical adenopathy and pelvic mass biopsies were performed. Immunohistochemistry concluded an ALK-positive ALCL with a small-cell pattern. The patient was treated with brentuximab-based chemotherapy and eventually improved. Differential diagnosis of pelvic masses in children and adolescents must include ALCL. An inflammatory trigger may promote the appearance of a typical nodal disease, previously absent. Attention is warranted during histopathological examination to avoid diagnostic errors.

Embryonal rhabdomyosarcoma of the uterine cervix in an adult female.

Embryonal rhabdomyosarcoma (RMS) of the female genital tract is an uncommon malignancy, presenting mainly in the pediatric and adolescent populations, primarily affecting the first two decades of life. This malignancy presentation in adulthood is rare and is seldom seen. The incidence of this tumor affecting adult females is approximately 0.4 - 1%, with the common site being the vagina. This tumor infrequently involves the cervix. RMS has a poor survival rate and once diagnosed, it requires aggressive management by radical surgery accompanied by chemoradiation. We present a case of an anaplastic variant of embryonal RMS of the uterine cervix presenting as a cervical polyp in a 36-year-old female who complained of dyspareunia and post-coital bleeding.

Non-inferior efficacy of non-surgical treatment to surgical treatment in patients with nonmetastatic head and neck rhabdomyosarcoma: a SEER-based study.

PURPOSE: Head and neck rhabdomyosarcoma (HNRMS) is a rare but aggressive malignant neoplasm. Given the young patient age and critical anatomy of the head and neck, performing surgery on the primary tumor still remains debatable. This study aimed to evaluate the impact of the non-surgery-based treatment versus surgery-based treatment on patients with nonmetastatic HNRMS. METHODS: Patients diagnosed with nonmetastatic HNRMS between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database were enrolled in our study. Inverse probability treatment weighting (IPTW) method was employed to balance confounding factors between surgery and non-surgery groups. Kaplan-Meier methods and COX regression analyses were used to analyze survival outcomes of overall survival (OS) and cancer-specific survival (CSS). Prognostic nomogram was established to predict survival. RESULTS: A total of 260 eligible patients were extracted from the SEER database. Kaplan-Meier survival curves revealed that there was no significant difference in OS and CSS between the surgery and non-surgery groups both before and after IPTW (p > 0.05). Cox regression analyses and IPTW-adjusted Cox regression analyses for both OS and CSS showed similar survival between the two groups. Prognostic factors were explored and a nomogram for patients in the surgery group was constructed. Risk stratification based on the nomogram indicated that patients in surgery-high-risk group did not benefit from primary surgery. While those in surgery-low-risk group had an equal survival outcome to those in non-surgery group. CONCLUSIONS: Our study revealed that compared to patients receiving surgery, those not receiving surgery had similar survival outcomes for nonmetastatic HNRMS. Our established nomogram may serve as a practical tool for individual prognostic evaluations.

Rhabdomyosarcoma of the oral cavity in children aged 0-2 years: A scoping review.

BACKGROUND: The aim of this study was to collect, synthesize, and analyze the clinic-demographic data of rhabdomyosarcoma affecting the oral cavity of young children. METHODS: The clinical question was "What are the clinical characteristics of oral rhabdomyosarcoma in children aged zero to two years?" Two independent reviewers selected the studies, extracted data, and assessed the methodological quality through the Joanna Briggs Institute Checklist. Descriptive statistics were performed in SPSS. (protocol: osf.io/b9hvy). RESULTS: Thirty case reports with 41 patients were included (22 males; mean age at diagnosis: 15 months). All studies had some methodological limitations, mainly due to the lack of clarity for a final judgment. More than 70% of the cases affected the tongue or lips. Tumors had a fast growth (mean 2.5 months), usually with red coloration, and variable shape and consistency. Embryonal (63.41%) and alveolar (29.27%) were the most common histological subtypes. Treatment was quite variable but usually included surgery. Most patients (53.66%) were alive without disease at follow-up. CONCLUSION: Oral rhabdomyosarcoma is rare in children aged 0-2 years without a marked gender predilection. The tumor presents as a fast and infiltrative growth leading to local and/or systemic symptoms, and a favorable prognosis for most patients.

Intraosseous Spindle Cell/Epithelioid Rhabdomyosarcoma with TFCP2 Rearrangement: A Recent Recognized Subtype with Partial Response to Alectinib.

Rhabdomyosarcoma affects mainly pediatric patients and is currently classified into four categories: embryonal, alveolar, pleomorphic, and spindle cell/sclerosing. Recently, a molecular group of spindle cell/sclerosing rhabdomyosarcoma demonstrated new fusion transcripts involving FET-family genes with TFCP2. In this report, we describe a rare case of spindle cell/sclerosing rhabdomyosarcoma in a 19-year-old woman, presenting as a destructive lesion involving the condyle of mandible. Next generation sequencing was performed, revealing a FUS::TFCP2 fusion and deletion of ALK gene. Alectinib therapy was initiated, which resulted in a favorable response for 4 months. However, the patient died due progression of the tumor. To make an accurate diagnosis and ensure appropriate patient management, it is necessary to be aware of this variant and use proper immunohistochemical stains when facing malignant mesenchymal bone lesions, expanding its differential diagnosis.

Rhabdomyosarcoma with TFCP2 Rearrangement or Typical Co-expression of AE1/AE3 and ALK: Report of Three New Cases in the Head and Neck Region and Literature Review.

BACKGROUND: Rhabdomyosarcoma (RMS) harboring EWSR1/FUS-TFCP2 fusions has been recently described as a distinct form of RMS with an aggressive course and predilection for the craniofacial bones, especially the jaws. METHODS: We report three new cases of this rare entity, two from Brazil and one from Guatemala, with detailed clinicopathologic, immunohistochemical, and molecular descriptions. Additionally, we explored the English-language literature searching RMS with TFCP2 rearrangement or typical immunophenotype with co-expression of AE1/AE3 and ALK in the head and neck region. RESULTS: Case 1 is a 58-year-old male with a 3-month history of painful swelling in the anterior maxilla. Case 2 is a 22-year-old male presenting with right facial swelling and proptosis. Case 3 is a 43-year-old female with a rapidly growing tumor located in the zygomatic region. Imaging examinations revealed highly destructive intraosseous masses in the first two cases, and a soft tissue tumor with bone invasion in case 3. Microscopically, all cases showed a hybrid spindle and epithelioid phenotype of tumor cells which expressed desmin, myogenin and/or Myo-D1, AE1/AE3, and ALK. FISH confirmed molecular alterations related to TFCP2 rearrangement in Cases 1-2. In case 3, there was no available material for molecular analysis. The patients were subsequently referred to oncologic treatment. Additionally, we summarized the clinicopathologic, immunohistochemical, and molecular features of 27 cases of this rare RMS variant in the head and neck region reported in the English-language literature. CONCLUSION: RMS with TFCP2 rearrangement is a rare and aggressive tumor with a particular predilection for craniofacial bones, especially the jaws. Knowing its clinicopathologic and immunohistochemical profile can avoid misdiagnosis.

Rhabdomyosarcoma in low- and middle-income countries: A report from the Asociacion de Hemato-oncología Pediatrica de Centro América (AHOPCA).

This report describes the results of an observational study dedicated to rhabdomyosarcoma developed by the Asociación de Hemato-oncología Pediatrica de Centro América (AHOPCA) between 2001 and 2018. Overall, 337 previously untreated patients < 18 years old were included in the analysis; 58% had unresected disease, and 19% were metastatic at diagnosis. With a median follow-up of 6.6 years, five-year event-free and overall survival rates were 30% and 33%, respectively. Local progression/relapse was the main cause of treatment failure.

Embryonal rhabdomyosarcoma of the uterine cervix in an adult female

ABSTRACT Embryonal rhabdomyosarcoma (RMS) of the female genital tract is an uncommon malignancy, presenting mainly in the pediatric and adolescent populations, primarily affecting the first two decades of life. This malignancy presentation in adulthood is rare and is seldom seen. The incidence of this tumor affecting adult females is approximately 0.4 - 1%, with the common site being the vagina. This tumor infrequently involves the cervix. RMS has a poor survival rate and once diagnosed, it requires aggressive management by radical surgery accompanied by chemoradiation. We present a case of an anaplastic variant of embryonal RMS of the uterine cervix presenting as a cervical polyp in a 36-year-old female who complained of dyspareunia and post-coital bleeding.

Report of a Primary Testicular Embryonal Rhabdomyosarcoma.

Primary testicular rhabdomyosarcoma is a rare pediatric genitourinary tumor with few cases reported in the literature. The clinical presentation is identical to that of other common testicular neoplasms. Diagnosis entails careful microscopic examination and immunohistochemical analysis to rule out other primary testicular malignancies. Treatment consists of radical orchiectomy and adjuvant chemotherapy with possible retroperitoneal lymph node dissection. This multimodal approach is required to improve survival outcomes and reduce disease recurrence. We present the case of a primary testicular embryonal rhabdomyosarcoma in a 19-year-old male who presented with a rapidly, enlarging, painless testicular mass. He was treated with radical orchiectomy and adjuvant chemotherapy. Once found with metastatic disease, he then received salvage chemotherapy and radiotherapy without success.

[Primary pulmonary rabdomyosarcoma: clinical-pathological and immunohistochemical findings]. / Rabdomiosarcoma pulmonar primario: hallazgos clínico-patológicos e inmunohistoquímicos.

Pulmonary rhabdomyosarcona is a rare entity and the histopatological differential diagnosis can be difficult. We report on a case of a 48-year-old male patient with a neoplasm located at the hilum of the right lung. The histological study of the lobectomy specimen allowed the diagnosis of embryonal rhabdomyosarcoma to be made. Given the absence of tumor lesions in other sites, it was classified as primary pulmonary neoplasm. The patient underwent chemotherapy and subsequently a completion pneumonectomy for recurrence of the tumor. One year after the initial surgery, he presented a metastasis in the right adrenal gland. He died 20 months after the original diagnosis. The importance of immunohistochemistry in the diagnosis is emphasized and the different theories that attempt to explain the histogénesis of these tumors in unusual sites are analyzed.

El rabdomiosarcoma pulmonar es una entidad rara y muy poco frecuente, más aún en la población adulta, lo que puede dificultar el diagnóstico correcto. Se presenta el caso de un varón de 48 años con un tumor pulmonar. El estudio histológico reveló que se trataba de un rabdomiosaroma embrionario pulmonar primario. Dada la ausencia de lesiones tumorales en otros sitios fue catalogado como primario pulmonar. El paciente realizó quimioterapia y posteriormente fue sometido a una neumonectomía por recidiva de la neoplasia. Al año de la cirugía inicial presentó una metástasis en glándula suprarrenal derecha. Falleció al cabo de 20 meses del diagnóstico original. Se enfatiza la importancia de la inmunohistoquímica en el diagnóstico y se analizan las distintas teorías vigentes que intentan explicar la histogénesis de estos tumores en sitios no habituales.

[Embryonal botryoid rhabdomyosarcoma of the uterus]. / Rabdomiosarcoma embrionario botrioide de útero.

Rhabdomyosarcoma is a malignant neoplasm of mesenchymal origin with skeletal striated muscular differentiation. It is the most common sarcoma of childhood and has four subtypes: embryonal, alveolar, pleomorphic and spindle cell/sclerosing. Of all of them, the embryonal one is the most prevalent and presents a variant, botryoid, which usually involves hollow organs in the form of a multilobed polypoid mass. We present the case of a 27-year-old woman who consulted for vaginal bleeding and in whom colposcopy revealed a whitish polypoid lesion that was externalized through the external cervical os. Histological examination revealed cellular sectors alternated by lax, myxoid areas, together with typical isthmic-endometrial glands. The atypical spindle cell proliferation was arranged in nests, made up of ce lls with large eosinophilic cytoplasm with transverse cytoplasmic striations and eccentric nuclei with homogeneous chromatin. Areas of densely packed cells were exhibited immediately, but separated from, the intact epithelial lining by a thin layer of loose stroma (cambium layer). The immunostaining profile was positive for desmin, muscle-specific actin and myogenin, and negative for smooth muscle actin. A diagnosis of embryonal botryoid rhabdomyosarcoma of the uterine corpus was made.

El rabdomiosarcoma es una neoplasia maligna de origen mesenquimal con diferenciación muscular estriada esquelética. Es el sarcoma más común de la infancia y presenta cuatro subtipos: embrionario, alveolar, pleomórfico y de células ahusadas/esclerosante. De todos ellos el embrionario es el de mayor prevalencia y presenta una variante, botrioide, que suele comprometer órganos huecos en forma de una masa polipoide multilobulada. Presentamos el caso de una mujer de 27 años que consultó por sangrado vaginal y en quien se evidenció en la colposcopia, una lesión polipoide blanquecina que se exteriorizaba a través del orificio cervical externo. El estudio histológico reveló sectores celulares alternados por áreas laxas, mixoides, junto a glándulas ístmico-endometriales típicas. La proliferación fusocelular atípica, se disponía en nidos, constituidos por células de amplio citoplasma eosinófilo con estriaciones citoplasmáticas transversales y núcleos excéntricos con cromatina homogénea. Se exhibían áreas de células densamente condensadas inmediatas y próximas al revestimiento epitelial intacto, pero separadas de él, por una fina capa de estroma laxo (capa cambial). El perfil de inmunomarcación resultó positivo para desmina, actina músculo específico y miogenina, y negativo para actina músculo liso. Se realizó diagnóstico de rabdomiosarcoma embrionario botroide de cuerpo uterino.

Rabdomiosarcoma pulmonar primario: hallazgos clínico-patológicos e inmunohistoquímicos / Primary pulmonary rabdomyosarcoma: clinical-pathological and immunohistochemical findings

Resumen El rabdomiosarcoma pulmonar es una entidad rara y muy poco frecuente, más aún en la población adulta, lo que puede dificultar el diagnóstico correcto. Se presenta el caso de un varón de 48 años con un tumor pulmonar. El estudio histológico reveló que se trataba de un rabdomiosaroma embrionario pulmonar primario. Dada la ausencia de lesiones tumorales en otros sitios fue catalogado como primario pulmonar. El pa ciente realizó quimioterapia y posteriormente fue sometido a una neumonectomía por recidiva de la neoplasia. Al año de la cirugía inicial presentó una metástasis en glándula suprarrenal derecha. Falleció al cabo de 20 meses del diagnóstico original. Se enfatiza la importancia de la inmunohistoquímica en el diagnóstico y se analizan las distintas teorías vigentes que intentan explicar la histogénesis de estos tumores en sitios no habituales.

Abstract Pulmonary rhabdomyosarcona is a rare entity and the histopatological differential diagnosis can be difficult. We report on a case of a 48-year-old male patient with a neoplasm located at the hilum of the right lung. The histological study of the lobectomy specimen allowed the diagnosis of embryonal rhabdomyosarcoma to be made. Given the absence of tumor lesions in other sites, it was classified as primary pulmonary neoplasm. The patient underwent chemotherapy and subsequently a completion pneumonectomy for recurrence of the tumor. One year after the initial surgery, he presented a metastasis in the right adrenal gland. He died 20 months after the original diagnosis. The importance of immunohistochemistry in the diagnosis is emphasized and the different theories that attempt to explain the histogénesis of these tumors in unusual sites are analyzed.

Rabdomiosarcoma embrionario botrioide de útero / Embryonal botryoid rhabdomyosarcoma of the uterus

Resumen El rabdomiosarcoma es una neoplasia maligna de origen mesenquimal con diferenciación muscular estriada esquelética. Es el sarcoma más común de la infancia y presenta cuatro subtipos: embrio nario, alveolar, pleomórfico y de células ahusadas/esclerosante. De todos ellos el embrionario es el de mayor prevalencia y presenta una variante, botrioide, que suele comprometer órganos huecos en forma de una masa polipoide multilobulada. Presentamos el caso de una mujer de 27 años que consultó por sangrado vaginal y en quien se evidenció en la colposcopia, una lesión polipoide blanquecina que se exteriorizaba a través del orificio cervical externo. El estudio histológico reveló sectores celulares alternados por áreas laxas, mixoides, junto a glándulas ístmico-endometriales típicas. La proliferación fusocelular atípica, se disponía en nidos, constituidos por células de amplio citoplasma eosinófilo con estriaciones citoplasmáticas transversales y núcleos excéntricos con cromatina homogénea. Se exhibían áreas de células densamente condensadas inmediatas y próximas al revestimiento epitelial intacto, pero separadas de él, por una fina capa de estroma laxo (capa cambial). El perfil de inmunomarcación resultó positivo para desmina, actina músculo específico y miogenina, y negativo para actina músculo liso. Se realizó diagnóstico de rabdomiosarcoma embrionario botroide de cuerpo uterino.

Abstract Rhabdomyosarcoma is a malignant neoplasm of mesenchymal origin with skeletal striated mus cular differentiation. It is the most common sarcoma of childhood and has four subtypes: embryonal, alveolar, pleomorphic and spindle cell/sclerosing. Of all of them, the embryonal one is the most prevalent and presents a variant, botryoid, which usually involves hollow organs in the form of a multilobed polypoid mass. We pres ent the case of a 27-year-old woman who consulted for vaginal bleeding and in whom colposcopy revealed a whitish polypoid lesion that was externalized through the external cervical os. Histological examination revealed cellular sectors alternated by lax, myxoid areas, together with typical isthmic-endometrial glands. The atypical spindle cell proliferation was arranged in nests, made up of ce lls with large eosinophilic cytoplasm with transverse cytoplasmic striations and eccentric nuclei with homogeneous chromatin. Areas of densely packed cells were exhibited immediately, but separated from, the intact epithelial lining by a thin layer of loose stroma (cambium layer). The immunostaining profile was positive for desmin, muscle-specific actin and myogenin, and negative for smooth muscle actin. A diagnosis of embryonal botryoid rhabdomyosarcoma of the uterine corpus was made.

Metastatic primary brain rhabdomyosarcoma in a pediatric patient: illustrative case.

BACKGROUND: Primary intracranial rhabdomyosarcoma is an extraordinarily rare malignant tumor, with even fewer presenting with distant metastasis. To date, only five cases, including the one presented here, have been reported to present metastatic activity. OBSERVATIONS: A 12-year-old boy presented with a few days of headache, nausea, vomiting, but no neurological deficit. Brain computed tomography and magnetic resonance imaging demonstrated hydrocephalus and a cystic lesion with left parieto-occipital extension. After resection, pathology reported primary rhabdomyosarcoma, with positive desmin and myogenin on immunohistochemistry. The patient presented with pulmonary metastasis. The patient had an overall survival of 21 months after diagnosis with optimal treatment. LESSONS: Rhabdomyosarcoma is a malignant neoplasm arising from undifferentiated skeletal muscle cells, with morphological, immunohistochemical, ultrastructural, or molecular genetic evidence of primary skeletal muscle differentiation. It presents with a rapidly worsening clinical course and the final outcome is poor. Treatment is widely based on protocols that have been proven to be effective in extracranial versions of these tumors, although repeatedly ineffective. Primary brain rhabdomyosarcoma poses a diagnostic challenge because of its infrequent presentation, grade of undifferentiation and tumor heterogeneity. Immunohistochemical and genetic testing have proven to be useful tools for diagnosis.