Rosai-Dorfman disease presenting as a solitary mediastinal mass

Rosai-Dorfman Disease: Rare Pulmonary Involvement Mimicking Pulmonary Langerhans Cell Histiocytosis and Review of the Literature

Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy, is a rare nonmalignant lymphohistiocytic proliferative disorder. We report a patient with RDD who presented with multiple skin lesions, pulmonary involvement, and CT manifestations mimicking Langerhans cell histiocytosis, which improved after initiation of corticosteroid treatment.

Membranoproliferative glomerulonephritis associated with Rosai-Dorfman disease

Rosai-Dorfman disease is also known as sinus histiocytosis with massive lymphadenopathy. Extranodal Rosai-Dorfman disease has been reported in ~ 43% of cases; the most frequent extranodal sites – skin, soft tissue, bone, respiratory tract, and eye – are usually involved in association with lymphadenopathy. Lack of lymph node involvement is rare, especially when patients manifest renal disease. Here, we describe a patient who developed membranoproliferative glomerulonephritis when lymphadenopathy was absent. During follow-up for sinus histiocytosis, a 7-year-old Japanese boy developed proteinuria and hematuria. No renal abnormality was present in ultrasound imaging. Histologic examination of a renal biopsy specimen disclosed moderate mesangial proliferation, focal thickening of glomerular capillary walls, and mesangial interposition. Mononuclear cells infiltrated the interstitium. Immunofluorescence showed intense IgG, C3, and C4 reactivity in portions of the mesangium and glomerular capillary walls. Electron microscopy depicted nodular deposits in mesangial, endocapillary, and subepithelial areas. Immunohistochemistry for S-100 protein, CD68, and lysozyme was positive within the interstitium. CD1a staining was absent. These findings were diagnostic for membranoproliferative glomerulonephritis. Multidrug therapy, including methylprednisolone and mizoribine, improved urinary findings and induced complete remission of both diseases. To the best of our knowledge, this is the first report of Rosai-Dorfman disease complicated by renal disease in the absence of concurrent nodal involvement. Clinicians should be alert to this diagnostic possibility.

Updates on histiocytic disorders

Histiocytic disorders are rare entities that are becoming more recognized as our understanding of the molecular pathogenesis lead to novel diagnostic tests and targeted drug development. A symposium held at the American Society of Pediatric Hematology/Oncology (ASPHO) 2013 Annual Meeting discussed new insights into histiocytic disorders. This review highlights the symposium presentations, divided into three sections encompassing Langerhans cell histiocytosis (LCH), hemophagocytic lymphohistiocytosis (HLH) and Rosai Dorfman disease (RDD) including subsections on pathogenesis, clinical diagnostic criteria and novel insights into treatment. Details of other histiocytic disorders as well as the standard treatment guidelines have been published elsewhere and are beyond the scope of this discussion [Haupt et al. (2013). Pediatr Blood Cancer 60:175-184; Henter et al. (2007). Pediatr Blood Cancer 48:124-131].

Intrathoracic Rosai-Dorfman disease with spontaneous remission: a clinical report and a review of the literature

Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy, is a rare non-neoplastic disease that is characterized by a proliferation of histiocytes mostly in lymph nodes. However, the etiological mechanism of RDD still remains unclear. Intrathoracic manifestations of RDD are only observed in 2% of patients with RDD. Spontaneous remission was reported in about 20% of patients with RDD; however, there are no reports of an intrathoracic manifestation of RDD that showed a spontaneous remission within a short period of time. A 64-year-old Japanese female with dry cough and left chest pain was introduced to our hospital, and computed tomography revealed a pulmonary nodular lesion and enlarged mediastinal lymph nodes. The bronchial specimen obtained from the abnormal mucosal lesion showed massive infiltration of histiocytes underneath the bronchial epithelium and emperipolesis, a typical pathological finding in RDD, which is characterized by the presence of histiocyte-like cells engulfing intact lymphocytes. These histiocytes were positive for S-100 (one of the known positive markers of RDD) and for CD68 (a marker for various cells of the macrophage lineage). All these findings are consistent with the diagnosis of RDD. These radiological and endoscopic findings spontaneously resolved within four months without any treatment. In conclusion, clinicians should be aware of this disease as one of differential diagnoses of pulmonary nodules in combination with mediastinal lymph node enlargements, especially in order to differentiate it from primary lung cancer.