Cutaneous Rosai-Dorfman Disease With Linear Lesions and Monoclonal Gammopathy.

Cutaneous Rosai-Dorfman disease (CRDD), a benign histiocytosis of unknown etiology, typically presents as a solitary or clusters of lesions. Although the histopathology is fairly distinctive, the laboratory abnormalities are not; past reports note elevated erythrocyte sedimentation rate, anemia, and polyclonal hyperglobulinemia. We describe a 61-year-old African American diabetic gentleman who presented with nodules in a linear distribution on the flank. Histopathologic examination of a biopsied nodule revealed a pandermal sheet-like infiltrate of plasma cells and histiocytes, some demonstrating elastophagocytosis and emperipolesis. The lesional histiocytes were S100 and CD68 positive and CD1a negative-findings consistent with a diagnosis of CRDD. Additional laboratory work-up performed 12 weeks after the biopsy was taken revealed an elevated serum κ light chain concentration of 37.26 mg/L (reference range: 3.30-19.40 mg/L), which correlated with an M-protein spike identified as IgG κ proteins per serum protein electrophoresis. Given the difficulty in excising a large area and preexisting diabetes, a course of low-dose methotrexate was selected for therapy with a recommendation of close follow-up for the monoclonal gammopathy. To the best of our knowledge, this is the first report of CRDD associated with a linear distribution of lesions and serum protein electrophoresis-confirmed monoclonal gammopathy.

Congenital subungual melanocytic nevus with a pseudo-Hutchinson sign.

We describe a 29-year-old woman with congenital melanonychia striata and compound nevus of the right first digit. There was extension of the hyperpigmentation onto the proximal nail fold, even beyond the borders established by the band of melanonychia striata. A dermal plaque with irregular borders and variegated pigmentation was also present over the distal digit extending from the pigmented region of the hyponychium. A limited number of biopsy proven congenital subungual melanocytic nevi have been reported in the literature. Interestingly, we found that the majority of these cases present with longitudinal melanonychia in association with periungual hyperpigmentation, constituting a pseudo-Hutchinson sign. Currently studies evaluating the diagnostic test characteristics of Hutchinson sign are lacking. While Hutchinson sign is traditionally considered a worrisome feature it is certainly not pathognomonic and a malignant cause should not be assumed without thorough assessment.

Focal preauricular dermal dysplasia: report of two cases and a review of literature.

We report two cases of focal preauricular dermal dysplasia and review the available literature. Focal preauricular dermal dysplasia is a form of aplasia cutis congenita in which atrophic skin lesions occur in a stereotypical bilateral distribution in the preauricular region. Although focal preauricular dermal dysplasia and membranous cutis aplasia of the scalp share clinical similarities, focal preauricular dermal dysplasia represents a form of aplasia cutis congenita that is not typically associated with extracutaneous anomalies.

Pharmacologic immunomodulation and cutaneous malignancy in rheumatoid arthritis, psoriasis, and psoriatic arthritis.

OBJECTIVE: It is unclear if skin cancer risk is affected by the use of immunomodulatory medications in rheumatoid arthritis (RA), psoriasis, and psoriatic arthritis (PsA). The purpose of this study is to evaluate and summarize the available data pertinent to this question. METHODS: The English language literature on PubMed was searched with a combination of phrases, including "malignancy," "skin cancer," "squamous cell carcinoma," "basal cell carcinoma," "melanoma," "psoriasis," "psoriatic arthritis," and "rheumatoid arthritis" in addition to the generic names of a variety of common immunomodulatory drugs. Relevant articles were identified and data were extracted. RESULTS: In total, 2218 potentially relevant articles were identified through the search process. After further screening, 20 articles relevant to RA were included. An additional 19 articles relevant to either psoriasis or PsA were included as well. RA may be a risk factor for the development of cutaneous malignancy. Treatment with tumor necrosis factor inhibitors increases the rates of non-melanoma skin cancer (NMSC) in RA and psoriasis. This risk doubles when combination methotrexate therapy is used in RA. Methotrexate may increase the risk of malignant melanoma in patients with RA and the risk of NMSC in psoriasis. Cyclosporine and prior phototherapy significantly increase the risk of NMSC. CONCLUSION: RA may potentiate the risk of cutaneous malignancy and therefore dermatologic screening in this population should be considered. The use of immunomodulatory therapy in RA, psoriasis, and PsA may further increase the risk of cutaneous malignancy and therefore dermatologic screening examinations are warranted in these groups. More careful recording of skin cancer development during clinical trials and cohort studies is necessary to further delineate the risks of immunomodulatory therapy.