Adult rhabdomyoma in the parapharyngeal space: report of 2 cases and review of the literature

Case Report: Unveiling the unexpected: a rare case of adult-type rhabdomyoma in a 9-year-old boy

Rhabdomyoma is an exceedingly rare benign soft tissue tumor of skeletal muscle origin, classified into cardiac and extracardiac types based on location. Extracardiac rhabdomyoma further includes adult, genital, and fetal types depending on the degree of differentiation. Most patients are between 40 and 70 years old, with a mean age of 60 years and a male predominance. This case report presents a 9-year-old boy diagnosed with an oropharyngeal tumor, initially presenting with a 6-month history of a foreign body sensation in the throat, presenting as night-time snoring. Postoperative histological examination revealed adult rhabdomyoma, characterized by specific immunohistochemical and histologic traits including cytoplasmic positivity for muscle-specific Actin (MSA), Desmin, Myogenin, and MYOD1, large polygonal skeletal muscle cells and frequent extensive vacuolization. This report highlights the unusual age of presentation for this variant and underscores the need for heightened clinical awareness to ensure accurate diagnosis and effective management of such rare occurrences.

High 18F-fluoro-2-deoxy-D-glucose uptake in adult-type rhabdomyoma of the larynx

Rhabdomyomas are rare benign mesenchymal tumors of the skeletal muscles and uncommon in the head and neck region. Laryngeal rhabdomyomas are much rarer. We present the case of a 32-year-old woman who was admitted to our hospital for shortness of breath due to pneumothorax. As otolaryngologists, we were consulted for a soft tissue tumor over the left side of the larynx that was accidentally found on the chest computed tomography (CT). The patient underwent laryngomicrosurgery for tumor biopsy, and histological examination revealed a laryngeal rhabdomyoma. After the operation, magnetic resonance imaging of the neck was performed and the tumor was suspected as rhabdomyosarcoma. Positron emission tomography/computed tomography (PET/CT) showed an 18F-fluoro-2-deoxy-D-glucose (FDG)-avid soft tissue mass on the left side of the larynx. After complete tumor removal via transoral laser microsurgery, no recurrence was reported for 5 years.

Rhabdomyoma of the Oral Cavity Mimicking Reactive Lesions: A Case Report and Review of the Literature

Extracardiac rhabdomyoma is a tumor that rarely occurs in head and neck region. Adult and fetal types of extracardiac rhabdomyoma are diagnosed only by histopathological examination. In the oral cavity, this lesion usually affects the mouth floor and tongue. Despite the low incidence, adult rhabdomyoma should be considered in the differential diagnosis of oral cavity lesions, and histopathological evaluation might be helpful for the final diagnosis. This study aims to report a rare case of rhabdomyoma mimicking reactive lesions and review the literature. A 34-year-old male was referred to the pathology department with a yellowish sessile lesion in the labial maxillary vestibule. During an excisional biopsy, a mass of unencapsulated soft tissue beneath the vestibular mucosa was observed. The yellowish color in clinical features has led to lipoma as the initial clinical diagnosis. The histological examination exhibited an encapsulated, well-circumscribed benign neoplasm composed of multiple lobules of large polygonal cells with prominent abundant granular eosinophilic cytoplasm. No cellular atypia was observed. Diagnosis of the adult type of rhabdomyoma was made by collective agreement. Rhabdomyoma can be mistaken for other reactive lesions and may resemble their appearance.

Simultaneous Malignant and Benign Nonepithelial Neoplasms of the Larynx-A Case Report and Literature Review

Nonepithelial tumors of the larynx are relatively rare neoplasms of the head and neck. The chondrosarcoma, which develops commonly from cricoid and thyroid cartilage, stands for 0.2% of the laryngeal malignant neoplasms. The rhabdomyoma is even more uncommon benign tumor developing from the laryngeal striated muscles. The clinical manifestation and the treatment options depend on the histopathological evaluation, tumor localization, and its size. In presented case, the simultaneous occurrence of benign and malignant tumors of mesenchymal origin in the patient's larynx was provoking hoarseness, globus sensation, and dysphagia. To the best of authors' knowledge, no other case of the concomitance of rhabdomyoma and chondrosarcoma of the larynx have been reported in the literature.

Adult-Type Rhabdomyoma of the Omohyoid Muscle

Rhabdomyomas are benign tumors composed of mesenchymal tissue and having a histologic appearance similar to skeletal muscle. Extracardiac rhabdomyomas are rare, and the majority of the adult subtype occur in the head and neck (H&N) region. Diagnosis can be challenging due to fine-needle aspiration (FNA) and core needle biopsy being suspicious for sampling error from surrounding muscle or concerning for rhabdomyosarcoma. We present a case of a slowly enlarging left neck mass in the strap musculature of a 45-year-old Hispanic male. Multiple FNA and core biopsies failed to establish a diagnosis, and excisional biopsy was pursued revealing a hypertrophied left inferior belly of the omohyoid muscle. Histological analysis was diagnostic of an adult-type extracardiac rhabdomyoma, with complete surgical excision being the gold standard treatment for these tumors. The patient had an uneventful recovery. Skeletal muscle tumors of the H&N are uncommon, and benign extracardiac rhabdomyoma must be considered in the differential diagnosis to prevent unnecessarily aggressive intervention and appropriate patient counseling before and after surgery.

Primary parapharyngeal leiomyosarcoma: A case report

Leiomyosarcoma is a rare malignant soft-tissue tumor whose cells resemble smooth-muscle tissue. It has been reported to arise in different areas of the head and neck region. Primary leiomyosarcoma of the parapharyngeal space, however, is extremely rare, as only 4 cases have been previously reported to date. We describe the somewhat urgent case of a primary leiomyosarcoma of the right parapharyngeal space in a 30-year-old man. We also review the diagnostic and therapeutic challenges that clinicians face in managing this rare tumor.