Sc. Somach et al., PIGMENTED LESIONS IN ACTINICALLY DAMAGED SKIN - HISTOPATHOLOGIC COMPARISON OF BIOPSY AND EXCISIONAL SPECIMENS, Archives of dermatology, 132(11), 1996, pp. 1297-1302
Background and Design: A consecutive sample of 46 cases was collected
for comparative histologic evaluation. Results of incisional biopsies
of cutaneous pigmented lesions interpreted as lentigo maligna, melanom
a in situ. or invasive melanoma, and those suggestive, but not diagnos
tic, of melanoma were collected. Those lesions that were on actinicall
y damaged skin and in which biopsy was followed by complete excision w
ithin 6 months were included. Incisional biopsies that removed greater
than 50% of the surface area of the lesion were excluded. Results: Of
the excisional specimens, 40% demonstrated histopathologic features m
ore pronounced than those in the biopsy specimens. Areas of invasive m
elanoma not detected in the biopsy specimens were obsen ed in 20% of t
he excisional specimens. Accurate diagnosis based on small biopsy spec
imens was not always possible because of the absence of a classic lent
igo maligna histologic pattern in many cases. The most frequent deviat
ion from the pattern was the presence of lentiginous epidermal hyperpl
asia within these lesions. Conclusions: These results suggest that lim
ited sampling may be inadequate for an accurate diagnosis of pigmented
melanocytic lesions on actinically damaged skin. Areas chosen for bio
psy may not contain the most advanced areas histologically and may fai
l to detect foci of invasive melanoma elsewhere within the lesion.