Angiofollicular lymph node hyperplasia resembling a spinal nerve sheath tumor: a rare case of Castleman's disease.

BACKGROUND CONTEXT: Angiofollicular lymph node hyperplasia (Castleman's disease) is a lymphoproliferative disorder of unknown etiology. Although uncommon, the localized form of this disease can manifest in the central nervous system, typically as a meningeal-based intracranial lesion. Castleman's disease involving the spine is exceedingly rare. This represents only the second reported case of a patient with Castleman's disease whose presentation mimicked that of a spinal nerve sheath tumor.

PURPOSE: We report a rare case of angiofollicular lymph node hyperplasia that mimicked a spinal nerve sheath tumor and was treated with gross total resection.

STUDY DESIGN: Case report.

PATIENT SAMPLE: A 31-year-old female with angiofollicular lymph node hyperplasia presenting with a paraspinal mass.

OUTCOME MEASURES: The patient's outcome was based on clinical history, physical and radiographic examinations.

METHODS: A 31-year-old woman with a mediastinal mass previously diagnosed as sarcoid via biopsy presented with the new onset of radicular pain and radiographic enlargement of her mass. Magnetic resonance imaging demonstrated a 4.3x5.7x6.0 cm homogenously enhancing soft-tissue lesion that emanated from and widened the T3/T4 neural foramen on the left. The differential diagnosis based on the location of the lesion and imaging characteristics included schwannoma, neurofibroma, paraganglioma, sarcoid, and lymphoma. Gross total resection was performed via thoracotomy. Histological examination identified angiofollicular lymph node hyperplasia (Castleman's disease) of the hyaline-vascular subtype. The patient did not receive adjuvant chemotherapy or radiation therapy.

RESULTS: The patient had resolution of her symptoms without any clinical or radiographic evidence of recurrence at 1-year follow-up using magnetic resonance imaging with and without contrast.

CONCLUSIONS: Castleman's disease is a rare pathologic entity that should be considered in the differential diagnosis of a patient with a paraspinal mass. Spine surgeons should be aware of this diagnosis as it has treatment and follow-up implications that differ from the neoplasms it can mimic. Complete surgical excision is an effective treatment for solitary lesions. Screening for concurrent and future malignancies in these patients is prudent.