Radiological and clinicopathological analysis of intraspinal primary Rosai-Dorfman disease

Abstract

Background Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy (SHML), is a non-neoplastic histiocytic proliferation predominantly affecting lymph nodes, and usually presents with massive painless cervical lymphadenopathy accompanied by fever and weight loss. Extranodal involvement occurs in over 40% of patients; however, isolated extranodal disease without lymph node involvement is unusual. Although extranodal involvement has been reported in diverse sites, central nervous system manifestation, particularly in spinal cord is distinctly rare. It is a diagnostic challenge for radiologists and histopathologists to differentiate RDD from other spinal lesions because of its similarities in radiological and histological findings. Herein we describe a case of unusual isolated RDD in spinal cord. The radiology and clinicopathology of this lesion, as well as its differential diagnosis are discussed.  Methods The clinical manifestation of a patient with intraspinal primary RDD occurring C_3-6 level was presented retrospectively. Gross resected mass was routinely paraffin-embedded and stained with hematoxylin and eosin. Dako EnVision immunohistochemical staining system was used to detect the tumor antigen expressions, including S-100 protein (S-100), CD1a and CD68 (KP-1).  Results A 25-year-old female patient presented with 3-month history of numbness and weakness in both upper limbs associated with an increasing neck back pain. There was no fever and lymphadenopathy found in the patient. MRI of the whole spine revealed a subdural mass extending from C₃ to C₆ level of cervical spinal cord with homogeneous enhancement after contrast administration. Laminectomy and midline opening of the dura were performed. The subdural lesion appeared to have no capsule and attach the dura mater. The lesion was removed totally. Under the microscopic examination, dense fibrosis and intense chronic inflammation with focal neutrophilic infiltrates were noted. The clusters of large histiocytes with eosinophilic, finely granular cytoplasm and multinucleate giant cells were also observed in the lesion. Emperipolesis with intact lymphocytes within the cytoplasm of the large histiocytes were present. Mitotic activity and necrotic area were not observed. Special stains for organisms were negative. By immunohistochemical analysis, the characteristic histiocytes were positive for S-100 and CD68 and negative for CD1a. Based on clinical presentations and histological findings, a final histological diagnosis of primary RDD in spinal cord was made according to the criteria of WHO classification. The patient did not receive chemotherapy and radiotherapy, and attended follow-up for 12 months, without any neurological deficit or signs of recurrence.  Conclusions Isolated intraspinal RDD is rare. The definite diagnosis of this lesion should be made under the microscopical examination because the preoperative radiological appearance of the lesion does not differ from other lesions occurring in spinal cord, such as inflammatory pseudotumor, meningioma and lymphoma. Although good prognosis is obtained from gross total resection in most of reported patients with this lesion, recurrence could be found in individual cases, and chemotherapy and (or) radiotherapy had been applied for a few cases with multiple organs involvement to control the progression of lesion. Due to the rarity of its site, the strictly differential diagnosis should be made when the isolated RDD is encountered in spinal cord.

doi: 10.3969/j.issn.1672-6731.2014.04.011