Abstract
Introduction:
Sinus histiocytosis with massive lymphadenopathy (SHML) also known as Rosai – Dorfman disease is a disease of bone marrow stem cell origin. It affects lymph nodes primarily. Solitary bone lesions are very rare and can cause diagnostic difficulty.
Aim:
To increase the awareness of SHML as a cause of cystic bone lesions.
Materials and methods:
A 2 year old presented with 4 months history of pain and swelling of the distal forearm. There was no history of tuberculosis or HIV disease. The swelling was 4 × 3 cm firm, non-fluctuant and slightly tender. There were no lymph nodes. Radiographs showed an oval cystic lesion expanding with a well-defined margin. The ulnar cortex was deficient. CT scan confirmed a cystic lesion with contents of granulation tissue. The Hb and WCC were normal, ESR 20 was, CRP<5 and mantoux was negative.
At surgery the lesion was curretted. The contents resembled tuberculous granulation but there was no caseation. The borders were well formed, the ulnar cortex was deficient
Results:
The histology revealed granulation tissue with numerous large histiocytes and immuno chemistry confirmed Rosai Dorfman disease. Healing with sclerosis was seen at 6 months.
Discussion:
Rosai Dorfman disease is a systemic disease of bone marrow stem cells and lymphadenopathy is the prominent manifestation. Only ±8% of cases have been reported with bone involvement and 4% of these had no lymphadenopathy. The lesions are cystic and medullary but cortical involvement can occur. Solitary ossseous lesions characterized by a background of histocytes without eosinophils can mimic Langerhans histocytosis, localized osteomyelitis, fibrous dysplasia, tuberculosis, simple or aneurysmal bone cysts and metastatic deposits
Conclusion:
Lesions of haematopoetic origin should be considered in the diagnosis of lucent bone lesions in children.
