Intraoral adult rhabdomyoma: a case report

S-100 Immunohistochemical Positivity in Rhabdomyoma: An Underestimated Potential Diagnostic Pitfall in Routine Practice

A 66-year-old man presented with a 2.8 cm lesion of the left vocal cord. On contrast-enhanced computed tomography scans, the tumor extended to the supraglottis, subglottis, paraglottic space and anterior commissure, causing partial obstruction of the laryngeal lumen. At another hospital, a fragmented incisional biopsy was diagnosed as a granular cell tumor, as to the S-100 immunohistochemical positivity. After excision, the tumor revealed to be an adult-type laryngeal rhabdomyoma. The typical cytoplasmic rod-like inclusions and cross striations were more evident in the second specimen. We confirmed the unusual S-100 immunohistochemical positivity (variable intensity, >90% of tumor cells). Muscle markers were not performed on the previous biopsy, resulting positive in our specimen (Desmin: strong, diffuse expression; Smooth Muscle Actin: strong staining in 10% of tumor cells). Melan-A, CD68, GFAP, pan-cytokeratins, CEA, calretinin and neurofilaments resulted negative. To our brief, systematic literature review, S-100 positivity (usually variable, often weak or patchy/focal) was globally found in 19/34 (56%) adult-type rhabdomyomas of the head and neck region. Especially on fragmented biopsy material, the differential diagnoses of laryngeal rhabdomyomas may include granular cell tumors, oncocytic tumors of the salivary glands or of different origin, and paragangliomas.

Oral Adult Rhabdomyoma

This report describes a case of an adult rhabdomyoma (ARM) occurring in the oral cavity. A 47-year-old man was referred for the diagnosis of a painless, well-circumscribed, submucous nodule located on the floor of the mouth, measuring approximately 6.0 cm in length. Computed tomography revealed a well-defined, solid, and hypodense mass. A benign salivary gland or mesenchymal tumor were the main diagnostic hypotheses. Under local anesthesia, the patient underwent surgical excision. Microscopically, the tumor comprised large polygonal well-defined cells with abundant, eosinophilic granular cytoplasm with cross striations. No atypia or mitosis was observed. The cells were positive for muscle-specific actin, desmin, and sarcomeric alpha-actin. Based on these features, a diagnosis of ARM was established. No recurrence was observed after 48 months. Although rare, ARM should be considered in the differential diagnosis of oral submucosal nodules, especially those located on the floor of the mouth.

Rare Diseases of the Salivary Glands and of Facial Nerve

Salivary gland diseases are rare. In the European Union (EU) a disease is considered to be rare if not more than 5 of 10,000 people are affected by it. According to estimates in Germany are about 4 million people with a rare disease. In the EU are about 30 million people with rare diseases [1]. In the present work most of the described diseases of salivary glands and of the facial nerve fall in this category. They form a very heterogeneous group whose treatment takes place mainly in specialized centers. Still, it is essential for the otolaryngologist to identify and to diagnose these diseases in order to initiate the right therapeutic steps. The work is a compilation of innate andacquired rare salivary gland disorders and of rare facial nerve disorders. The etiologies of inflammatory diseases, autoimmune disorders and tumors are taken into account. For the individual topics, the current literature, if available, was evaluated and turned into summarized facts. In this context the development of new processes, diagnostics, imaging and therapy are considered. Genetic backgrounds of salivary gland tumors and the trends in the treatment of tumorous lesions of the facial nerve are picked up. Furthermore, also rare diseases of the salivary glands in childhood are described. Some of them can occur in adults as well, but differ in frequency and symptoms. Due to the rarity of these diseases, it is recommended to tread these in centers with special expertise for it. Finally, the difficulties of initiation of studies and the problems of establishing disease registries concerning salivary gland disorders are discussed. This is very relevant because these pathologies are comparatively seldom.

Multinodular adult rhabdomyoma in female: A rare case report

Rhabdomyomas are rare benign mesenchymal tumors of striated muscle origin. These are classified as cardiac and extracardiac types. Extracardiac type is further classified as adult, fetal and genital types. Adult rhabdomyoma represents <2% of all muscular tumors. It mostly occurs in adults (median: 60 years). Males are more commonly affected (M:F = 3:1) and usually present as solitary lesion. We report a rare case of multinodular adult rhabdomyoma arising from the floor of the mouth. A 55-year-old female presented with a painless, soft, mobile, nontender and multinodular swelling in the right submandibular region and the floor of the mouth for 2 months. Fine-needle aspiration cytology showed cellular smears of large elongated to round cells with abundant eosinophilic granular cytoplasm, small nuclei and occasionally prominent nucleoli. Histology revealed partially encapsulated lesion showing sheets of large, oval to polygonal cells with abundant deeply eosinophilic and granular cytoplasm, with small peripherally placed nuclei with few cells showing prominent nucleoli. Prominent cytoplasmic vacuolations (periodic acid-Schiff positive) were present. The cells were positive for desmin and myogenin. This case is an extremely rare presentation of multinodular adult rhabdomyoma in a female. The correct identification of this lesion is important to avoid an unnecessarily aggressive resection, yet providing potentially curative therapy.

Extra-tongue oral granular cell tumor: Histological and immunohistochemical aspect

BACKGROUND

Granular cell tumor (GCT) is an uncommon benign tumor founded in any part of the body but mainly in the tongue. Extra-tongue oral granular cell tumor (ETOGCT) is rare with few cases reported. Here we describe seven cases of oral GCT located in sites other then the tongue and discuss histopathological and immunohistochemical differences between differential diagnoses.

MATERIAL AND METHODS

We retrieved all cases diagnosed with oral granular cell tumor, from the Oral Pathology Service at the School of Dentistry/ University of São Paulo, and excluded the ones sited in the tongue. Immunohistochemical staining anti-S100 was also performed.

RESULTS

The presented cases of Extra-tongue Oral Granular Cell Tumor (ETOGT) are composed by granular cells with intimately association with the adjacent tissue. Atypia and mitoses were not seen, and in most cases, the typical pseudoepitheliomatous hyperplasia was not observed.

CONCLUSIONS

The importance of an adequate attention is to avoid misdiagnoses, since ETOGT is rare and the tricking histopathological findings could induce to it. All the cases can be differentiated from the tumors that has a granular cell proliferation through a morphological analysis and when needed, immunohistochemistry stain.

Fetal Rhabdomyoma of the Right Tonsil with Polyp-Like Appearance

Skeletal muscle neoplasms, in contrast to other groups of tumors, are almost malignant. The benign variant, rhabdomyoma, is distinctly rare. Rhabdomyomas can be classified generally into two types: cardiac and extracardiac. Extracardiac rhabdomyoma can be further divided into three subtypes: adult, fetal, and genital type. Adult rhabdomyoma is the most common subtype of rhabdomyoma even though it remains relatively rare. Fetal rhabdomyomas are less common than the adult type. In this paper we report a rare case of a fetal rhabdomyoma with polyp-like appearance originating from right tonsil. Punch biopsy and then right tonsillectomy were performed for complete excision. There was no obvious recurrence.