Vascular retardation in dormant growth-stunted malignant melanomas

Progression and metastatic spread of primary cutaneous melanoma (PCM) is la rgely predicted by the thickness of the primary tumor. However, the accreti ve or proliferative pattern of growth of PCM is another aspect that might a ffect the prognosis. We retrieved from our histopathological files 11 super ficial spreading PCM which had been documented to show an almost stable siz e for at least 3 years before excision. The area of the PCM at the skin sur face had been measured by planimetry on the excision specimens. Histologica l sections were used to measure the maximum thickness of the neoplasms. A P CM volume estimate was derived by multiplying the surface area by the thick ness of the tumors. In addition, the vessel area was determined beneath and outside the PCM lateral margins on Ulex europaeus agglutinin-1-stained sec tions using computer-assisted image analysis. Peritumoral vascularity was s ignificantly more developed than at distance of the neoplasms. A significan t negative exponential correlation was yielded between the peritumoral vasc ularity and the PCM volume estimate. Such vascular eclipse might be the cau se of clinical PCM dormancy. However, other possible independent mechanisms are not ruled out by the present study.