[Local recurrence and metastasis of thin malignant melanomas (less than or equal to 1mm)]

A total of 704 patients with malignant melanoma (MM) were documented in our clinical registry at the Department of Dermatology in Berlin from 1969 to 1987. At the time of first diagnosis 631 patients in this group were found to have clinical stage I disease, and complete histological reports were available for 516 of these cases. Of the 516 patients, 191 had thin MM (less than or equal to 1 mm) and in 10% of this group local recurrences or distant metastasis were seen. Nevertheless, recurrences were delayed in patients with thin MM compared with those with thicker MM (greater than 1 mm) (mean: thin MM 37 months, thicker MM 17 months), and patients with thin MM died of distant metastasis after longer time periods (mean: thin MM 67 months, thicker MM 33 months). The thinnest tumours followed by distant metastasis and death measured 0.40 mm and 0.45 mm in male and 0.63 mm and 0.72 mm in female patients. For thin MM, wide surgical total excision with safety margins (3-5 cm) was performed in 151/191 patients. No local recurrences were observed in this group, but primary lymphogenous and/or haematogenous metastasis was recorded in 12 patients (= 8%). Narrow surgical excision (less than or equal to 1.5 cm safety margin) was performed in 37/191 patients with thin MM; 6 patients (= 16%) in this group developed local recurrences, and in 2 of those lymphogenous or haematogenous metastasis occurred later. Another patient in this group showed primary haematogenous metastasis. Of 6 patients with local recurrences, 1 died of MM 13 years after the first diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)