# “Primary Chronic Granulomatous Sialadenitis of the Parotid Gland: A Rare Case Report”

## TL;DR

This paper presents a rare case of chronic granulomatous sialadenitis in the parotid gland, emphasizing the diagnostic challenges and the importance of combining multiple methods for accurate diagnosis.

## Contribution

The paper contributes a rare clinical case and highlights the need for a stepwise diagnostic approach for non-neoplastic parotid lesions.

## Key findings

- Chronic granulomatous sialadenitis can mimic benign tumors and may require surgical excision for definitive diagnosis.
- FNAB has high specificity and predictive values but may not always confirm non-neoplastic lesions.
- Inflammatory parotid lesions require clinico-pathological and immunohistochemical correlation for accurate diagnosis.

## Abstract

Parotid gland tumors account for 1-3% of head and neck tumors and approximately 70-80% of all salivary gland neoplasms, most of which are benign and predominantly occur in adults. However, non-neoplastic parotid lesions, such as chronic granulomatous sialadenitis, are rare entities with an estimated incidence of 1.7%. They may present as slow-growing, painless masses that are clinically indistinguishable from benign tumors, representing a diagnostic challenge. Case Report: We report the case of a patient with a left parotid mass of two years' evolution, initially evaluated by fine-needle aspiration biopsy (FNAB) (reported as Milan category II, non-neoplastic) and subsequently treated with surgical excision. Histopathological analysis revealed chronic granulomatous sialadenitis, with no evidence of infectious agents or apparent systemic involvement, suggesting a possible autoimmune or idiopathic origin. Discussion: FNAB is the initial diagnostic method of choice due to its low cost, accuracy, and minimal complication rate. It shows a sensitivity of 80%, specificity of 97%, positive predictive value of 90%, and negative predictive value of 94%. However, when cytological findings do not allow confirmation of the nature of the lesion, or when the clinical course is atypical, surgical excision with subsequent histopathological evaluation becomes necessary. Ideally, intraoperative biopsy analysis should be available to establish the definitive diagnosis. Conclusion: Granulomatous reactions in the parotid gland may result from ductal obstruction, specific infections, or systemic granulomatous diseases, making clinico-pathological and immunohistochemical correlation essential. This case highlights the importance of considering inflammatory lesions in the differential diagnosis of parotid masses and the need for a stepwise approach that combines cytology, imaging, and selective surgery.