Pigmented basal cell carcinoma: increased melanin or increased melanocytes?

BACKGROUND: Studies on the precise cause of increased melanization in pigmented basal cell carcinomas (BCC) are limited. We aimed to determine whether the cause of melanization is from increased number of melanocytes or increased melanin pigment, and if there is a difference in the number of melanocytes on different sun-exposed locations. METHODS: A retrospective review of 45 skin biopsies from January 2011 to February 2011 was performed; 30 were diagnosed as pigmented BCC and 15 as non-pigmented BCC. Immunohistochemistry for MART-1 (melanoma-associated antigen recognized by T-cell 1)/Melan-A (clone M2-7610 + M2-9E3; Leica Microsystems Inc. Buffalo Grove, IL, USA) from Biocare Medical (Concord, CA, USA) was performed on all biopsies. Associations between histopathologic features, number of melanocytes, location, and specific diagnoses were analyzed by Mann-Whitney U test. RESULTS: The mean melanocyte count per high powered field in pigmented BCCs from sun-exposed skin was 101.9 and from intermittently sun-exposed skin was 122.5, as compared to the controls (nodular non-pigmented BCC) of 27.4 (p = 0.002) and 34.9 (p = 0.002), respectively. CONCLUSIONS: Pigmented BCCs have a higher mean melanocyte count as compared to non-pigmented BCCs irrespective of location. Therefore, the pigment is not only due to increased melanin, but also due to increased melanocytes.

A case of non-Hodgkin's lymphoma-associated pemphigus foliaceus and use of rituximab for treatment.

BACKGROUND: Pemphigus foliaceus (PF), an autoimmune skin disorder resulting in the formation of superficial blisters, is a rarely reported skin manifestation of non-Hodgkin's lymphoma (NHL). Typical therapies for PF in non-malignant cases include immunosuppressants such as corticosteroids. We report the case of a patient undergoing therapy for NHL who subsequently developed PF which resolved following treatment with rituximab, an anti-CD20 monoclonal antibody. CASE REPORT: A 73-year-old Caucasian male who received a course of rituximab for NHL 3 years prior, presented with atypical urticarial lesions that developed into blisters. Pathological determination identified the lesions as PF. Traditional corticosteroid therapy failed to resolve the PF lesions. However, in this clinical situation, the patient responded to a repeat rituximab administration with complete resolution of the PF lesions. DISCUSSION: Paraneoplastic pemphigus, the most serious form of pemphigus, is more commonly associated with malignancies, such as NHL, whereas PF is seen in non-malignant cases. Although our patient was undergoing therapy for a malignancy, the less severe pemphigus emerged and responded to a non-traditional therapy. As such, we recommend that consideration is given to alternative therapies, including monoclonal antibodies, in cases of PF with atypical presentations and pathology associated with malignancy.