Clinical & Histological Review of Cutaneous Ro-sai-Dorfman Disease

Pathologists Juan Rosai and Ronald Dorfman initially described
in 1969 “sinus histiocytosis with massive lymphadenopathy” after
they observed symptomatic extensive lymph node enlargement...


Introduction
Pathologists Juan Rosai and Ronald Dorfman initially described in 1969 "sinus histiocytosis with massive lymphadenopathy" after they observed symptomatic extensive lymph node enlargement; and subsequently came to be designated "Rosai -Dorfman" disease [1].Rosai-Dorfman disease is a rare disorder characterized by increased production and accumulation of non-Langerhans sinus histiocytes within lymph nodes, most commonly affecting the cervical lymph node chain. Histiocytes may also accumulate in extranodal areas including the skin; central nervous system, kidney, and digestive tract.43% of cases of Rosai Dorfman disease demonstrate extranodal involvement. With skin being the most commonly site [2]. Thawerni et al were the first to report a case of cutaneous Rosai-Dorfman disease in 1978 [3].

Clinical Review
The aetiology of cutaneous Rosai-Dorfman disease is still unknown, immune and viral causes have been hypothesized. The signs and symptoms of this disease depend on which parts of the body are affected. Skin lesions seen in cutaneous Rosai-Dorfman disease are indurated firm papules or nodules measuring between 1-10 cm [1]. Age groups affected include children, adolescents and young adults [4]. The disease presents more commonly in males and in African descent [5]. Cutaneous Rosai-Dorfman disease (without nodal involvement) typically occurs at a later age of onset with a median age of 43.5 years and demonstrates female predominance with a ratio of (2:1), Asian and Caucasian individuals are mostly affected [6]. Laboratory findings are not specific and include: leucocytosis, elevated sedimentation rate and polyclonal gammopathy, elevated serum ferritin and normochromic/normocytic and autoimmune haemolytic anemia [7]. In our experience we recently encountered a patient who is       Treatment options reported in literature include surgical excision is recommended when lesion are localized, cryotherapy was successfully used for cutaneous Rosai-Dorfman syndrome that was refractory to topical and intralesional steroids [8].Dapsone was found to be effective in the treatment of cutaneous Rosai-Dorfman syndrome [9] ,100mg daily of dapsone was used to treat a patient with resistant to isotretinoin and oral, intralesional steroid with complete regression after 3 months of treatment with dapsone and patient remained in remission on his 1 year follow up [10].
Acitretin treatment for 4 months was found to be effective in a 12 year old patient [11,12]. High doses of Thalidomide (300 mg/d) can be effective in cases of extensive disease if patients can tolerate its side effects [13]. Other forms of treatment include isotretinoin, radiotherapy, Intralesional steroids.

Histology Review
The findings in Rosai-Dorfman disease and Cutaneous Rosai-Dorfman Disease are similar. Dermal infiltrates include large histiocytes, lymphocytes, and plasma cells. The histiocyte known as Rosai-Dorfman cell is considered diagnostic of Rosai-Dorfman disease, this cell is having an amorphous cytoplasm, large vesicular nucleus with prominent nucleoli and indistinct border [13]. Presence of lymphocytes and plasma cells engulfed within the cytoplasm of histiocytes is referred to as emperipolesis. This population express S-100 and are considered diagnostic although not pathognomonic of Rosai-Dorfman disease. This histiocytes population also may stain positive for CD68, and negative for CD1a [14,15], helping to exclude other differential diagnoses. In Immunohistochemistry demonstrated cells to be positive for S100, and variable CD68 positivity, but this population were negative with melanocytic markers including. Melan A and HMB45; other markers undertaken (CD1a, CD56, Factor 13a) were also negative as were special stains to exclude infective aetiology. S100 assisted in identifying emperipolesis as described by Brenn et al. [6] In conclusion the histological and immunohistochemical findings were all supportive of a pathological diagnosis of cutaneous Rosai-Dorfman disease.

Conclusion
Cutaneous Rosai-Dorfman disease is considered a distinct clinical entity of Rosai-Dorfman syndrome [14]. Extanodal Rosai-Dorfman disease without nodal involvement is extremely rare [6]; skin is considered the commonest extranodal site. Histologically Asians [16]. The diagnosis is made by histopathological examination looking for the presence of histiocytes that stain positive for S-100 and identification of emperipolesis [17]. Cutaneous Rosai-Dorfman syndrome is a benign condition which is self-limiting but may require treatment or surgical excision [18,19].