A comprehensive assessment of cutaneous Rosai-Dorfman disease.

BACKGROUND: Cutaneous Rosai-Dorfman (CRD) disease is a rare entity that is characterized by histiocytic proliferation in the skin. The disease has been reported to exhibit different clinical profiles and occasionally confounding histologic features that may be challenging for a correct diagnosis. The purpose of this study was to assess the pathobiology and highlight the variance in clinical and histologic spectrum of the disease based on published literature. METHODS: A PUBMED search was performed to retrieve cases of cutaneous Rosai-Dorfman disease published in the literature. A PRISMA-guided review of the included articles was performed. Three interesting case reports from our institution are also described. RESULTS: A total of 263 patients, of which 220 with purely cutaneous disease were identified in 152 studies. The mean age at presentation was 45.2 years with a slight female preponderance, and East-Asian, Caucasian and African populations being largely affected. Majority of the patients presented with multiple lesions, predominantly on limbs and comprising of nodules, plaques and papules that were occasionally pigmented. The classis histologic findings included large foamy histiocytes, exhibiting emperipolesis and a specific immunophenotype (S100+, CD68+, CD1a-). Inconspicuous emperipolesis, fibrosis, increased vascularity, neutrophilic microabscesses and concurrent langerhans cell histiocytosis and lymphoma in few cases highlighted the importance of immunohistochemistry for a definitive diagnosis. The disease shows an indolent and benign course with excision and chemotherapy being most effective for extensive and refractory cases. CONCLUSIONS: This review of largest cohort of CRD patients provides an updated insight into the clinicopathologic features with possible diagnostic pitfalls and effective therapeutic options that should be useful in diagnosis, management and future research opportunities.

S100-Negative, CD1a-Positive Cutaneous Histiocytosis in a Patient with S100-Positive, CD1a-Positive Pulmonary Histiocytosis.

In the diagnostic approach to histiocytic proliferations, immunohistochemistry may be a source of both confusion and clarification. We present a case of a 60-year-old man with a generalized pruritic eruption that demonstrated positive staining for CD1a, but negative staining for langerin and S100 protein. This immunophenotype is neither representative nor characteristic of any recognized dendritic cell tumor but has been previously described in 3 cases of skin-limited histiocytosis. However, our patient also demonstrated pulmonary histiocytic infiltrates that were positive for both CD1a and S100 proteins. This differing expression of S100 protein witnessed in 2 separate organ systems affords us insight into the pathophysiology of these histiocytic proliferations.

D-2-Hydroxyglutaric Aciduria with Enchondromatosis and Angiokeratoma Circumscriptum.

In this study, we report a four-year-old male with D-2-hydroxyglutaric aciduria (D2HA) and enchondromatosis with a prior history of hyperpigmented, segmental whorls and streaks on his abdomen who later presented with an eruption of angiokeratoma circumscriptum within a similar distribution. His condition can likely be explained by underlying somatic mosaicism; however, a unifying culprit gene mutation has not yet been identified. To date, only 10 reported cases of D2HA with enchondromatosis are available in the literature with three reported skin findings. This is the first reported case of angiokeratoma circumscriptum associated with the rare condition of D2HA and enchondromatosis.

Primary cutaneous CD30+ large cell B-cell lymphoma: a series of 10 cases.

BACKGROUND: White CD30 expression is described in extracutaneous diffuse large B-cell lymphomas, a primary cutaneous B-cell lymphoma (PCBCL) equivalent is not well defined. METHODS: Between June 1999 and July 2002 the authors encountered 10 patients with CD30+ PCBCLs of the large cell type. RESULTS: The patients comprised seven women and three men; five patients were over 80 years of age, all except one presenting with solitary plaques. With the exception of one death from myocardial infarction and one recurrence, all patients are well at a mean follow-up of 23.4 months. Skin biopsies showed a background of T-cell-rich reactive lymphoid hyperplasia in 7 of 10 patients, with variable granulomatous inflammation in 5 cases. The neoplastic large cells were immunoblastic in appearance. In four patients the infiltrate was dominated by large cells. In the remaining patients the reactive infiltrate defined the dominant cell population. The neoplastic cells expressed CD20, CD30, CD43, and BCL-2. In two cases associated with methotrexate therapy, Epstein-Barr virus expression was observed amid the neoplastic cell populace. CONCLUSIONS: CD30+ PCBCL is a distinctive form of B-cell lymphoma presenting in elderly patients and can be associated with a very good prognosis. In some patients the intensity of reactive inflammation obscures the diagnosis. In the authors' experience almost a third of the cases were associated with Epstein-Barr virus infection and methotrexate therapy, suggesting a distinctive association.

Eccrine angiomatous harmartoma in an infant.

Eccrine angiomatous hamartoma is a nevoid proliferation of eccrine glands and small vessels. It usually presents as a solitary, slow growing nodule, manifesting at birth or in childhood, which can be accompanied by hyperhidrosis and pain on palpation. We report an occurrence in an otherwise healthy 3-month-old girl who had multiple, asymptomatic, nodular lesions with a linear arrangement localized to the inguinal fold. We also review the literature on adnexal hamartomas of infancy.