Follicular Dendritic Cell Sarcoma of the Tonsil: A Multimodality Approach.

Area of Science:

• Oncology
• Pathology
• Surgical Oncology

Background:

• Follicular dendritic cell sarcoma (FDCS) is a rare soft tissue sarcoma, representing less than 0.4% of all soft tissue sarcomas.
• Tonsillar involvement is uncommon, with only 35 reported cases, predominantly presenting as localized disease.

Observation:

• A 53-year-old male presented with an 11-month history of an enlarging neck mass, found to involve the tonsil and carotid triangle.
• Initial imaging indicated unresectable disease due to vascular involvement; initial biopsy suggested undifferentiated sarcoma.
• Pathological re-evaluation confirmed Follicular dendritic cell sarcoma (FDCS) based on CD21 positivity and negative CD1A/CD34 markers.

Findings:

• The patient received palliative chemotherapy (doxorubicin, dacarbazine) with partial response and stable disease.
• Third-line chemotherapy with gemcitabine and docetaxel resulted in 50% tumor regression, enabling surgical resection and radiotherapy.
• A trimodality approach (chemotherapy, surgery, radiotherapy with radiosensitizer) achieved disease control at 8-month follow-up, with manageable treatment-related complications.

Implications:

• This case underscores the importance of accurate pathological diagnosis in managing rare soft tissue sarcomas like FDCS.
• A multidisciplinary, trimodality treatment strategy can achieve good disease control even in advanced, unresectable FDCS of the tonsil.
• Effective therapeutic responses may still be achievable with third-line systemic therapy for FDCS.