Oncocytoma of the larynx

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.

Oncocytic meningioma: a case report and review of the literature

Oncocytic meningioma is an uncommon variant of meningioma, with only 20 reported cases to date, that is histologically characterized by the presence of neoplastic cells with granular eosinophilic cytoplasm rich in mitochondria. We present the clinicopathological features of a case of oncocytic meningioma in a 49-year-old Chinese female, along with a literature review. Brain computed tomography and magnetic resonance imaging demonstrated a slightly hyperintense mass located in the right frontal region and attached to the dura. In addition, it was homogeneously enhanced following contrast administration. She underwent gross total surgical resection of the tumor and adjacent dura. Grossly, the well-demarcated, nonencapsulated mass had a solid and tan-white appearance with soft and rubbery consistency. The lesions were composed primarily of sheets, nests, and cords of large polygonal bland cells with finely granular eosinophilic cytoplasm rich in mitochondria. Mitotic figures were rare, and necrosis was absent. There was no infiltration of the dura or brain cortex. Immunohistochemical staining revealed that the neoplastic cells were positive for vimentin, epithelial membrane antigen, antimitochondrial antibody, and progesterone receptor, whereas MIB-1 stained only approximately 1% of the tumor cells. This is the first known report of an oncocytic meningioma arising in a Chinese patient. The patient was followed for 19 months without any evidence of metastasis or recurrence.

Nonparotid parapharyngeal oncocytoma: a case report and literature review

Oncocytoma is a rare, benign salivary neoplasm composed of mitochondria-rich cells called oncocytes. Although oncocytoma usually occurs in the parotid glands, it has much less commonly been reported to occur in minor salivary gland tissues. Although there have been a few reported cases of oncocytomas being found in the parapharyngeal space, most if not all cases seem to be extensions of deep lobe parotid tumors. We present a case of a 73-year-old man with a previous history of prostate cancer that had the incidental finding of an (18)F-fluorodeoxyglucose (FDG) image of a highly avid parapharyngeal space lesion noted on a follow-up positron emission tomography-computed tomography (PET/CT) scan. Excision of the mass, through a transcervical approach, demonstrated it to be an isolated oncocytoma of the parapharyngeal space, noncontiguous with the parotid gland. Based on our literature search, this may be the first such reported case. A brief review of the available literature examining the known body of knowledge regarding these neoplasms is presented.

Laryngeal Oncocytic Cyst Presenting with an Acute Onset of Stridor

Oncocytic lesions of the larynx are rare. When they have occurred, their presentation has been varied; these tumors may he completely asymptomatic and discovered incidentally, hut more commonly they present with voice alteration. We report a case of an oncocytic cyst in a patient who presented with an acute onset of stridor. We also discuss the clinical manifestations and management of laryngeal oncocytic cyst and its relevant pathologic features.

Alveolar soft part sarcoma of the larynx: a case report of an unusual location with immunohistochemical and ultrastructural analyses

BACKGROUND

Alveolar soft part sarcoma (ASPS) is a rare mesenchymal neoplasm of uncertain origin. In this article, we report a case of ASPS occurring in the larynx, an extremely rare location for this rather unusual tumor.

METHODS AND RESULTS

The patient was a 34-year-old Japanese woman who requested an examination for hoarseness. The tumor showed a proliferation of large polygonal cells with periodic-acid-Schiff-positive diastase-resistant intracytoplasmic granules, arranged in an alveolar growth pattern. The cytoplasm of the tumor cells was eosinophilic. Tumor cells were positive for vimentin and titin. Nuclear immunoreactivity for TFE3 was observed, and the Ki-67 labeling index was 14.7%. Ultrastructurally, electron-dense rod-shaped crystals were infrequently observed in the cytoplasm. This case was finally diagnosed as ASPS of the larynx.

CONCLUSION

We discuss the histogenesis and differential diagnosis of ASPS with immunohistochemical and ultrastructural findings. TFE3 immunohistochemistry was found to be a very useful marker for the diagnosis of ASPS.

Oncocytic cyst presenting as laryngocele with surgical emphysema

We present a case of laryngeal oncocytic cysts presenting as bilateral laryngoceles and surgical emphysema of the neck. Although there is a rare, but well-documented association of laryngoceles with laryngeal carcinoma, coexistence with another laryngeal pathology is less well reported.

Oncocytic meningioma

Six cases of meningioma showing oncocytic changes are described. The lesions were composed mostly of sheets, nests, and cords of large polygonal cells with finely granular eosinophilic cytoplasm rich in mitochondria. Neoplastic cells showed nuclear pleomorphism with prominent nucleoli. Necrosis and high mitotic rate were present in the majority of cases. Oncocytic differentiation was demonstrated by conventional histology, immunocytochemistry, electron microscopy, and Western-blot analysis. Oncocytic meningiomas showed an aggressive behavior; recurrences were observed in three cases, and invasion of brain cortex was evident in other two cases.