Clinically relevant differences between amelanotic malignant melanoma and granuloma pyogenicum.

Abstract

Macroscopic discrimination between amelanotic malignant melanoma (aMM) and the so-called granuloma pyogenicum (GP) is often uncertain since reliable criteria for a clear differentiation of either growth are lacking. In a search of such criteria we analysed the data of 57 consecutive in-patients with cutaneous aMM and of 83 with GP presenting at our Department during the years 1970-1988. The following items were compared with each other: duration from growth onset to definite diagnosis, site of growth, age and sex of the patients. Significant differences (p less than 0.01) between either growth were found for all items evaluated. Our results substantiate the hitherto gained impression of a remarkably shorter median history of GP as compared to aMM (5 vs. 26 weeks). Furthermore, aMM prevailed in elder (age greater than 50 years) particularly female (70%) patients, whereas GP developed about equally in both sexes and at all ages. Site distribution was also found to differ for either growth (GP predominantly in the head and neck region, rarely on lower limbs; aMM in all areas, rarely on the trunk). These data yield additional measures for clinical distinction between aMM and GP.