Differential Diagnosis for Parotid Gland Biopsy Showing Fibroconnective and Fibroadipose Tissue

• Single Most Likely Diagnosis
  • Benign fatty infiltration or fibrosis of the parotid gland: This is a common finding in parotid gland biopsies, especially in older adults, and can be associated with various conditions, including aging, obesity, or previous inflammation.
• Other Likely Diagnoses
  • Sjögren's syndrome: Although primarily known for its lymphocytic infiltration, Sjögren's syndrome can also lead to fibrosis and fatty replacement in the parotid gland.
  • Chronic sialadenitis: This condition can result in fibrosis and the formation of fibroadipose tissue within the parotid gland due to long-standing inflammation.
  • Benign lipomatous lesions (e.g., lipoma, lipomatosis): These are benign tumors composed of adipose tissue and can occur within the parotid gland.
• Do Not Miss Diagnoses
  • Malignant salivary gland tumors with lipomatous or fibrous components (e.g., liposarcoma, malignant myoepithelioma): Although rare, these tumors can have a significant impact on prognosis and treatment.
  • Sarcoidosis: This systemic disease can affect the parotid gland, leading to granulomatous inflammation and potentially fibrosis, and is important to diagnose due to its systemic implications.
• Rare Diagnoses
  • Kimura disease: A rare, chronic inflammatory disorder that can affect the parotid gland and other head and neck tissues, leading to fibrosis and eosinophilia.
  • Parotid gland involvement in systemic diseases (e.g., amyloidosis, hemochromatosis): These conditions can lead to deposition of abnormal substances in the parotid gland, resulting in fibrosis and other tissue changes.