[Immediate examination of cryostat sections of malignant melanomas].

The use of cryostat sections in diagnosing malignant melanoma: Like other researchers, notably McGovern, we found cryostat sections to be a great help in the swift and accurate histological diagnosis of malignant melanoma. In 214 out of 242 cases (= 88,5%), the diagnosis made with paraffin sections confirmed the diagnosis made with cryostat sections. The thickness of the tumors differs between cryostat and paraffin sections; the degree of difference depends on the level of the malignant melanoma (Fig. 1). Edematous cells in particular shrink less in cryostat than in paraffin sections, and so differential diagnosis of nevoid lentigo, lentigo maligna and superficial spreading melanoma may be difficult.