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.
['Brankov|Nikoleta|N|', 'Prodanovic|Edward M|EM|', 'Hurley|M Yadira|MY|']
D000328:Adult D000368:Aged D014408:Biomarkers, Tumor D002280:Carcinoma, Basal Cell D016022:Case-Control Studies D005260:Female D006801:Humans D007150:Immunohistochemistry D058965:MART-1 Antigen D008297:Male D008543:Melanins D008544:Melanocytes D008875:Middle Aged D012189:Retrospective Studies D012878:Skin Neoplasms
pigmented basal cell carcinoma melanin melanocytes MART-1/Melan-A collision tumor