These benign tumors made up of nevus cells may be flat or raised, pigmented (Figure A) or nonpigmented.
Melanocytic nevi. These benign tumors made up of nevus cells may be flat or raised, pigmented (Figure A) or nonpigmented. There is a widespread belief that these nevi change during pregnancy, but very few studies document this. Although darkening of nevi may occur, significant alterations in their size do not necessarily occur during pregnancy. Therefore, if a pigmented lesion changes during pregnancy, a biopsy is warranted to rule out malignant melanoma (Figure B).
Earlier studies suggested that the prognosis for patients with primary cutaneous melanoma during pregnancy may be worse than the prognosis for patients who are not pregnant. However, several recent reports have shown no difference in survival between these two groups.