Extranodal Rosai-Dorfman disease. Clinical and pathological characteristics in a patient with a pseudotumor of bone

Primary intraosseous Rosai-Dorfman disease: An analysis of clinicopathologic characteristics, molecular genetics, and prognostic features

Background

Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder of uncertain pathogenesis. Most patients present with proliferation in the lymph nodes manifesting as adenopathy; however, RDD may primarily arise in a variety of extranodal sites, including the bone, which is a great challenge in the diagnosis. The clinicopathological characteristics and prognostic features of primary intraosseous RDD have not been well characterized.

Methods

We retrospectively analyzed the clinicopathologic and prognostic features of four cases of primary intraosseous RDD during the past 10 years in our hospital, with a review of an additional 62 cases with complete follow-up data from the literature.

Results

Primary intraosseous RDD was identified in 0.14% (4/2,800) of total bone biopsies performed at our institution over the study period. According to our retrospective analysis, a total of 18 cases of primary lymph node, skin, or other non-osseous site-based RDD were diagnosed in our hospital. The ages of the 66 total patients ranged from 1.5 to 76 years, with a median age of 25 years. There were 31 male and 35 female patients, with a male-to-female ratio of 0.89:1. Primary intraosseous RDD occurred most often in the bones of the extremities (60.6%, 40/66), with the proximal tibia being the most common location; 39.4% (26/66) of the cases arose in the axial skeleton, predominantly in the vertebra and craniofacial bones. Solitary masses and multiple tumors were present in 84.8% (56/66) and 15.2% (10/66) of the cases, respectively. Pain of the affected area was the most common presenting symptom. Radiographically, the lesions were lytic with well-defined and usually sclerotic margins. Immunohistochemistry showed that large histiocytes from patients with RDD were positive for OCT2, in addition to S100 and CD68. Molecular tests were performed in seven reported cases and four of our cases. All the 11 cases were non-decalcified. PCR results showed that there were no BRAF-V600E, KRAS, or NRAS mutations in primary intraosseous RDD; only one case with both RDD and Langerhans cell histiocytosis showed BRAF-V600E mutation. The survival data showed that 22.7% (15/66) of the patients experienced recurrences or developed RDD at distant sites during the follow-up period (median follow-up, 13 months; range, 1-106 months). The 5-year progression-free survival (PFS) of the patients with primary intraosseous RDD was 57.5%. We found that there was a significant difference in PFS between female and male patients (p = 0.031). However, there was no statistically significant difference in PFS between patients with solitary masses and multiple tumors (p = 0.698). Similarly, no statistically significant differences in PFS were found between the different age groups (p = 0.908) or tumor locations (p = 0.728).

Conclusion

Primary intraosseous RDD is an extremely rare disease. The diagnosis of RDD may be quite challenging because of its non-specific clinical presentation and imaging. Immunohistochemistry showed that large histiocytes were positive for OCT2 in addition to S100 and CD68, which may be helpful for differential diagnosis. Molecular detection showed that RDD may be related to the MAPK pathway, though these results are also ultimately not specific. The pathogenesis of RDD is yet to be elucidated, but recent studies suggest possible clonality of hyperproliferative histiocytes.

Osseous Rosai-Dorfman disease of tibia in children: A case report

BACKGROUND

Rosai-Dorfman disease (RDD), or sinus histiocytosis with massive lymphadenopathy, is a benign histiocytic disorder. Extranodal involvement is common, occurring in > 40% of patients, but bone involvement occurs in < 10% of cases. In addition, primary bone RDD is extremely rare. The majority of patients are adolescents and young adults, and the mean age at onset is 20-years-old.

CASE SUMMARY

We report an 8-year-old Chinese girl who presented to our hospital with an insidious onset of swelling and pain in the middle shaft of her right tibia for 4 mo. We performed total surgical resection of the right tibia lesion and allograft transplantation. A good prognosis was confirmed at the 6 mo follow-up. Pain and swelling symptoms were totally relieved, range of motion of her right knee and ankle returned to normal, and there was no clinical evidence of lesion recurrence at last follow up. Our case is the second reported case of osseous RDD without lymphadenopathy in the shaft of the tibia of a child.

CONCLUSION

Extranodal RDD is a rare disease and can be misdiagnosed easily. Lesion resection and allograft transplantation are an option to treat extranodal RDD in children with good short term result. Pediatric orthopedist should be aware of this rare disease, especially extranodal involvement.

Primary Rosai-Dorfman disease of bone arising in the infantile ilium: A case report

Rosai-Dorfman disease (RDD) is an extremely rare benign histiocytic disorder that usually affects young adults. Extranodal involvement of the RDD is common and may occur in >40% of patients, but bone involvement occurs in <10% of cases. Furthermore, primary bone RDD is extremely rare. The present study reports a case of primary bone RDD arising in the infantile ilium. Plain radiographs and computed tomography (CT) revealed an osteolytic lesion at the peri-acetabular region of the patient's right ilium. Fluorodeoxyglucose positron emission tomography indicated an abnormal accumulation only in the right iliac bone, without any other accumulation. An open biopsy was performed and the diagnosis of primary RDD of bone in the ilium was made. The bone lesion exhibited spontaneous regression on radiography, and the patient was able to walk without any limping or pain at 8 months after the biopsy. After 18 months of follow-up, the bone lesion had completely disappeared, and no joint deformity was observed on radiography or CT. The present report described the clinicopathological details of this rare case and reviewed the relevant literature.

Unusual presentation of Rosai-Dorfman disease (RDD) in the bone in adolescents

Rosai-Dorfman disease (RDD), or sinus histiocytosis with massive lymphadenopathy (SHML), is a rare idiopathic histiocytic disorder. The usual presentation of RDD is painless bilateral cervical lymphadenopathy. Extranodal RDD with lymphadenopathy occurs in almost 50% of patients but extranodal RDD, without lymphadenopathy, is very rare. Isolated RDD in the bone occurs in only 2% of patients but it is histologically similar to its nodal counterpart. There are only 14 previously reported cases of RDD in the bone without lymph node involvement in children. Here we describe two new patients--one with rib and lung involvement and the other with multi-osseous involvement.

Multifocal osseous involvement as the sole manifestation of Rosai-Dorfman disease

Rosai-Dorfman disease may involve extranodal sites exclusively. Osseous involvement as the sole manifestation of disease is uncommon. The present report describes a 60-year-old woman presenting with lytic lesions in the lower end of femur and mid-fibula on one side and unaccompanied by disease elsewhere.