Endobronchial follicular dendritic cell sarcoma.
Butler J, Yessayan L, and Simoff M. Endobronchial follicular dendritic cell sarcoma. Chest 2015; 148(4).
Follicular dendritic cells are found in the germinal centers of lymph nodes or extranodal lymphoid tissue and present antigen to B-cells. Tumors are rare and they make up less than 1% of soft tissue sarcomas. Here we discuss the case of a follicular dendritic cell sarcoma occurring as an endobronchial tumor. CASE PRESENTATION: A 19 year old African American female presented with fever, dyspnea, sore throat and productive cough. CT chest showed a 1cm endobronchial lesion within the right main bronchus causing lung collapse and post-obstructive pneumonia. She became hypoxic in the ER, intubated and started on broad spectrum antibiotic therapy. Fiberoptic bronchoscopy showed a 100% obstructing pearly-colored endobronchial lesion in the right mainstem bronchus just distal to the carina. She subsequently underwent rigid bronchoscopy with laser ablation and mechanical debulking. Frozen section revealed spindle cell sarcoma with necrosis, later identified as follicular dendritic cell sarcoma. Markers for CD35, vimentin, and CD99 were strongly positive. CT abdomen and pelvis was negative for metastatic disease. PET scan showed hypermetabolism in the right hilum and mild hypermetabolism in the axillary lymph nodes. She underwent right upper lobe sleeve lobectomy and level 10 lymph node resection, both specimens were negative for malignancy. Adjuvant chemotherapy was not given. Surveillance bronchoscopy with endobronchial biopsies years 1 and 2 post surgery were negative for recurrence. DISCUSSION: FDC sarcoma is a rare tumor and often misdiagnosed as lymphoma or carcinoma. Staining for markers such as CD21, CD35 is helpful. The etiology remains controversial but suggested predisposing factors from the literature include hyaline-vascular Castleman disease, Epstein Barr virus, paraneoplastic pemphigus, and myasthenia gravis. Histologic features such as high mitotic count and coagulative necrosis are associated with unfavorable outcome. For localized disease, surgical resection is the therapy of choice. Adjuvant chemoradiation therapy is usually Conclusions: FDCS should be considered in the differential diagnosis of any spindled-cell tumor occurring in the lung.