Extranodal follicular dendritic cell sarcoma involving tonsil

Area of Science:

• Oncology
• Pathology

Background:

• Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm originating from lymph nodes and extranodal sites.
• Extranodal FDCS are frequently misdiagnosed due to rarity, leading to delayed or incorrect treatment.
• Accurate diagnosis is crucial for managing FDCS, given its metastatic potential.

Observation:

• A 30-year-old female presented with a year of progressive throat pain and dysphagia.
• Examination revealed an ulceroproliferative growth on the left tonsil without lymphadenopathy.
• Histopathology showed an infiltrative tumor with ovoid to spindle cells in storiform and fascicular patterns.

Findings:

• Immunohistochemistry confirmed FDCS with positivity for CD21, CD23, CD35, and S-100 protein, and negativity for cytokeratin.
• The Ki-67 labeling index was 6%, indicating a low-risk classification.
• Epstein-Barr virus (EBV) status was negative.

Implications:

• This case underscores the diagnostic challenges of extranodal FDCS, particularly in the tonsil.
• Early and accurate diagnosis of tonsillar FDCS is essential for appropriate patient management and prognosis.
• Further awareness and diagnostic criteria refinement are needed for rare extranodal sarcomas.