A 77-year-old Hispanic woman presented with a lesion of one-year duration that was progressively enlarging on her left breast; the lesion would occasionally bleed. Clinical examination showed a 2 x 1 cm black nodule; in addition, extending from the base of the tumor onto the adjacent skin, was macular brown pigmentation (Figures -). There was no palpable neck, axillary, or inguinal lymphadenopathy. The clinical differential diagnosis included a nodular malignant melanoma.\nA biopsy was performed. Microscopic examination showed that the lesion consisted of two concurrent tumors. The first was an ulcerated nodular basal cell carcinoma with aggregates of basaloid tumor cells extending from the epidermis into the dermis; there was pigment in both the tumor cells and within the melanophages in the adjacent dermis. The second was a seborrheic keratosis showing acanthosis and hyperpigmentation. Correlation of the clinical presentation and pathology established the diagnosis of a collision tumor consisting of an ulcerated nodular basal cell carcinoma and a seborrheic keratosis.\nMohs surgery was performed. The tumor was cleared in one stage. A layered closure was used to repair the surgical defect (Figures -). Follow-up after three months did not reveal any recurrence.
A 74-year-old Hispanic woman presented with an asymptomatic lesion of one-year duration on the nasal tip. Clinical examination showed a nodular tumor; in addition to being black, there was ulceration (Figures -). There was no palpable neck lymphadenopathy. Morphologically, the clinical differential diagnosis included malignant melanoma.\nA biopsy was performed. Microscopic examination showed nodular aggregates of basaloid tumor cells extending from the epidermis into the dermis. There was pigment not only in the tumor cells but also within the melanophages in the adjacent dermis. Correlation of the clinical presentation and pathology established the diagnosis of pigmented nodular basal cell carcinoma.\nMohs surgery was performed. The tumor was cleared after three stages. A left paramedian forehead flap was performed to treat the surgical wound. Follow-up three months later showed excellent healing without recurrence of the skin cancer. However, there was significant hypertrichosis involving the tissue flap on the nasal tip (Figures -). This was remedied by using electrolysis to eliminate the hair.