Alveolar rhabdomyosarcoma on the external ear: a case report

Unusual outer ear swelling: Childhood auricular rhabdomyosarcoma

INTRODUCTION

Rhabdomyosarcoma (RMS) is the most frequent soft-tissue sarcoma in children and makes up 5% of all pediatric malignant tumors. The main head and neck locations are the base of the skull, nasopharynx, nasal cavity and orbit. An outer ear location is considered extremely rare. We present 3 cases of children, aged 6 to 14 years, presenting with auricular RMS.

CASE REPORTS

The first child, aged 6, was managed by 4 chemotherapy cycles followed by surgical resection of the tumor bed, completed by 5 further cycles of chemotherapy. The second, aged 14, was managed by 4 chemotherapy cycles followed by external radiation therapy of the tumor bed and lymph node areas, completed by 5 further cycles of chemotherapy. The third, aged 13, was managed by 4 chemotherapy cycles followed by surgery, completed by 5 further cycles of chemotherapy.

DISCUSSION

In these 3 patients, the treatment program achieved complete disease control. Prognosis was good, thanks to good surgical access. Diagnosis should be considered in case of unusual progressive swelling in the outer ear.

Embryonal rhabdomyosarcoma of the auricle in a child

We describe the diagnosis and management of a child with embryonal rhabdomyosarcoma of the auricle and emphasize both clinical and radiological findings of this rare condition. A nine-year-old boy presented for evaluation of a slowly enlarging left auricle mass. The mass was nodular, violaceous, semi-translucent, and hyperpigmented with an overlying pseudo-vesicular plaque. The mass appeared to involve the left cavum concha, root of the helix, superior aspect of the external auditory canal, the tragus and extend to a deep preauricular component. MR imaging documented a lobulated soft tissue mass surrounding the external auditory canal with superficial involvement of the pinna. Incisional biopsy of the mass suggested embryonal rhabdomyosarcoma. The tumor was completely removed by total auriculectomy and lateral temporal bone resection. The final diagnosis was embryonal rhabdomyosarcoma. Although rare, otolaryngologists, pediatricians, and radiologists need to consider rhabdomyosarcoma in the differential diagnosis of auricle mass in children.

Primary cutaneous rhabdomyosarcoma: a clinicopathologic review of 11 cases

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.

Rhabdomyosarcoma of the skin resembling carcinosarcoma: report of a case and literature review

Rhabdomyosarcomas (RMSs) are soft tissue sarcomas with skeletal muscle differentiation. Cutaneous RMSs are exceedingly rare, and in most cases, they represent metastatic disease or the dermal involvement by a tumor arising in the underlying soft tissues. We herein report the case of a 41-year-old man who developed a cutaneous swelling of the right nasal orbital angle. An initial incisional biopsy showed cytokeratin-positive atypical spindle cells forming long and intersecting fascicles, thus the case was diagnosed as carcinosarcoma. In the subsequent excisional biopsy, the skeletal myogenic differentiation of the tumor cells infiltrating the dermis and subcutis was demonstrated by morphology (presence of rhabdomyoblasts), immunohistochemistry (positivity for desmin, myogenin, myoglobin, and actins), and electron microscopy (evidence of rudimentary sarcomeric structures). A final diagnosis of primary cutaneous RMS was made. The patient was subjected to postoperative radiation and chemotherapy, but after 4 months, the patient developed a tumor recurrence followed by distant metastases and death. Review of the literature reveals that RMSs of the skin are often underrecognized and display peculiar clinical features in comparison with their more common soft tissue counterpart.

Rabdomiossarcoma alveolar cutâneo primário em paciente pediátrico

O rabdomiossarcoma é o tumor de partes moles mais comum na infância, sendo raro o acometimento exclusivamente cutâneo. Apresenta-se caso de criança com nódulo doloroso na face, cuja análise histopatológica e imunoistoquímica confirmou tratar-se de rabdomiossarcoma, o qual foi conduzido por equipe multidisciplinar. Os tumores de partes moles são responsáveis por 6% de todos os tumores infantis; destes, 53% são rabdomiossarcomas, que podem acometer qualquer sítio. A manifestação como nódulo dérmico é incomum, representando um desafio diagnóstico, já que não possui características clínicas que o diferenciem de outras patologias.