Bilateral parotid diffuse hyperplastic oncocytosis: Case report

A case report of synchronous bilateral multifocal nodular oncocytic hyperplasia in parotid gland

INTRODUCTION AND IMPORTANCE

Multifocal nodular oncocytic hyperplasia (MNOH), alternatively known as Benign Nodular Oncocytosis, was first identified by Schwartz and Feldman in Cancer in 1969. It manifests as numerous nodular growths of oncocytic cells scattered within the salivary gland tissue; Bilateral and multifocal lesions in the parotid gland are rare occurrences. Among these, bilateral multifocal oncocytic lesions are even less common.

CASE PRESENTATION

We report a case of 59-year-old woman with no prior medical or surgical history who presented to our ENT department due to a gradual, painless enlargement of both parotid glands that had been ongoing for four months. She underwent bilateral parotidectomy. Histologic exam confirmed the diagnosis of bilateral multifocal nodular oncocytic hyperplasia with a histological variant of clear cells. The postoperative course was unremarkable.

CLINICAL DISCUSSION

Diagnosis presents challenges due to the rarity of this condition. Precise diagnosis relies on imaging techniques such CT scans and MRI features. There is no consensus on the therapeutic management.

CONCLUSIONS

Our case report adds to the scarce literature concerning this condition, emphasizing the importance of careful clinical evaluation, precise diagnosis, and proper management.

Oncocytoma of the parotid gland: A rare benign tumour

Oncocytomas are one of the infrequent neoplasms seen in the oral cavity accounting for less than 2% of all neoplasms in the oral cavity with less than 1% chance of malignant transformation. They affect the major salivary glands and have a female predilection. The cognisance of the unique clinical and histopathological features is very important to conclude a confirmatory diagnosis. This paper reviews a case of oncocytoma presented in our department and also elucidates the diagnostic criteria for the same.

Parotid gland oncocytosis: Multifocal adenomatous oncocytic hyperplasia variant - A case report in Singapore

Oncocytosis is a rare, benign, non-neoplastic lesion that can be further classified into diffuse oncocytosis or multifocal adenomatous oncocytic hyperplasia. This tumour has been estimated to account for 0.1% of all parotid gland tumours.¹ Here, we report a rare case of a patient who presented to the Oral and Maxillofacial Surgery Department with a 3-cm swelling of his left parotid gland. Histopathological results from a superficial parotidectomy revealed the lesion to be a multifocal adenomatous oncocytic hyperplasia of the parotid gland. A description of this rare disease and its management are included in this article.

Multifocal Parotid Oncocytic Cystadenomatosis: A Rare Process that Can Mimic Malignancy

Multifocal cystic oncocytosis (MCO) is a rare, benign process accounting for approximately 0.1% of salivary gland lesions. Salivary oncocytosis is characterized by multiple unencapsulated solid nodules of oncocytic cells derived from transformed striated ducts. MCO is a variant of salivary oncocytosis which manifests as cystically dilated striated ducts. It is difficult to obtain a definitive preoperative diagnosis of MCO; therefore, these lesions are commonly treated with surgery. We report the unique case of a 66-year-old male who previously underwent a superficial left parotidectomy for a pleomorphic adenoma. Four years later, he presented with clinical and radiographic suspicion of a multifocal recurrent pleomorphic adenoma. The patient subsequently underwent a revision parotidectomy. However, final pathology confirmed a diagnosis of MCO. Although MCO is commonly treated with surgery due to lack of a definitive preoperative diagnosis, surgery is unnecessary outside of diagnostic, functional or cosmetic considerations. Thus, if a patient with parotid oncocytosis treated by superficial parotidectomy develops disease re-manifestation in the residual deep lobe, further surgery is not indicated. There is no risk of malignant progression in this process. We report on this unusual entity as it may mimic salivary malignancy or, as in this case, recurrence of benign disease.

Oncocytic lesion of parotid gland: A dilemma for cytopathologists

Oncocytes are epithelial cells with abundant, granular, eosinophilic cytoplasm due to presence of numerous large mitochondria of varied sizes. The presence of oncocytes in salivary glands can occur in a variety of conditions. Here, we present a rare case of a 68 year old male patient who presented with a 6 cm diameter swelling in the right parotid region. A fine needle aspiration cytology done from the lesion showed a cellular oncocytic lesion. A possibility of oncocytoma was entertained. Histopathology of the mass showed a rare entity called diffuse hyperplastic oncocytosis. Originally believed to be a metaplastic process, oncocytes can occur in various lesions ranging from hyperplastic conditions to malignant neoplasms. However, diagnosis on cytological smears can be very challenging for the cytopathologist.

L'hyperplasie oncocytaire nodulaire multifocale de la glande parotide

OBJECTIVES

Oncocytic lesions rarely affect the parotid gland, accounting for less than 1% of all salivary lesions. The WHO classification described three main types: diffuse oncocytosis, focal nodular oncocytosis hyperplasia, and oncocytoma. Multifocal nodular oncocytosis hyperplasia of the parotid gland represents an extremely rare, non-tumorous pathology of the parotid gland.

MATERIAL AND METHODS

We report a case of multifocal nodular oncocytosis hyperplasia of the parotid gland in a 70-year-old woman who was referred for a left preauricular mass that had gradually increased in size over the last 2 years. No lymph node of the neck was palpable.

RESULTS

MRI demonstrated multiple bilateral lesions of the parotid glands. Total parotidectomy, preserving the facial nerve, was performed.

CONCLUSION

We discuss the physiopathology and the treatment of multifocal nodular oncocytosis hyperplasia and provide a review of the literature.

[Masseter oncocytoma of parotid origin]

INTRODUCTION

Tumors developed in a salivary ectasia of the parotid gland are very rare. The authors describe a case of oncocytoma developed in such an ectopy.

OBSERVATION

The tumor located in the parotid region was observed in a 79-year old man. There was no facial palsy, no pain, and no cervical adenopathy. MRI was the most helpful to localize and characterize the tumor. Surgical resection was performed after a parotidectomy. Histology confirmed the diagnosis.

DISCUSSION

The physiopathology of this rare entity is discussed with a literature review. It might correspond to a mitochondrial anomaly.

Bilateral oncocytoma of the parotid gland

Oncocytic neoplasms are a group of rare tumours that mostly affect the parotid gland (80%), sometimes affect the submandibular gland (9%) and rarely affect the intraoral minor salivary glands. The incidence of oncocytic neoplasms represents approximately 1% of parotid neoplasms and bilateral presentation is very rare. Herein we describe a single case involving bilateral presentation of oncocytoma of the parotid glands.