Electron microscopic examination of cutaneous lesions by the quick re-embedding method from paraffin-embedded blocks

We attempted to evaluate whether Widéhn's quick re-embedding method from paraffin blocks is useful for dermatopathological diagnosis. Regarding fine preservation of nuclei, tono-fibrils and desmosomes of keratinocytes in normal skin, we could recognize no difference between the quick re-embedding method and traditional re-embedding methods. However, preservation of mitochondria and Birbeck granules in Langerhans cells was poor regardless of the method used. Furthermore, we studied the ultrastructural features of some viral skin diseases including molluscum contagiosum, herpes simplex, varicella-zoster and verruca vulgaris, and some skin tumors, including angioleiomyoma, angiosarcoma, Merkel cell carcinoma and amelanotic melanoma using the quick re-embedding method. We determined that all viral structures were sufficiently preserved by the quick method to observe the virions and development of the virus. Myofilaments and dense bodies of angioleiomyoma, Weibel-Palade bodies of angiosarcoma, neurosecretory granules of Merkel cell carcinoma and melanosomes of amelanotic melanoma were recognized by the quick method. From these results, we concluded that the quick re-embedding method is useful for the diagnosis of skin diseases, especially viral skin diseases and some skin tumors.