Macrophage subtypes in recurrent nodular basal cell carcinoma after Mohs micrographic surgery.

BACKGROUND: The macrophages associated with solid tumors are related to the progression or regression of tumors, depending on the differentiation in M1 or M2. M2 subtype promotes angiogenesis, remodeling, and tissue repair (tumor proliferation). In contrast, M1 produces toxic mediators and presents antigens, destroying microorganisms and tumor cells. The microenvironment of most aggressive forms of basal cell carcinoma (BCC) shows an increase in macrophages due to M2 phenotype compared to noninvasive forms. The treatment of nodular BCC by Mohs micrographic surgery (MMS) provides high cure rates, but relapses can occur.

AIMS: To compare the total population of macrophages and their subpopulations M1 and M2 in cases of recurrent and nonrecurrent nodular BCC after excision by MMS.

MATERIALS & METHODS: Histological sections obtained from paraffin blocks of nine cases of recurrent nodular BCC after MMS and 18 cases of nonrecurrent nodular BCC operated by MMS were immunostained for iNOS, CD204, CD163, and CD68. The expression of these markers was analyzed by image analysis.

RESULTS: No significant differences were found between the groups in relation to the average percentage of M1 cells, M2 cells, and total cells.

DISCUSSION AND CONCLUSION: A relationship was not seen between tumor-associated macrophages (TAM) and tumor recurrence.