๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Epidermoid cyst of the sole
Clinical features Epidermoid cyst of the sole has been described mainly in the Japanese.1โ5 A single case report documents the lesion in a non-Japanese.6 Involvement of the palm has also been reported.4 The cyst likely represents an implantation variant.7 It is of particular interest as it has been shown to be associated with HPV infection in some cases (see below).5 An exceptional giant lesion extending from the sole into the dorsum of the foot through the interosseous muscles has been described.8
Histologic features Histologically, it is characterized by the presence of eosinophilic intracytoplasmic inclusions in the wall of the cyst and vacuolated cells in the keratin layer.2,5 Parakeratosis with absence of the granular cell layer is sometimes noted in the more superficial portion of the cyst.9 The cyst is filled with orthokeratotic keratin. Immunoperoxidase confirms the presence of viral antigen, and inclusions have been identified ultrastructurally.2,5 HPV 57 and 60 have been demonstrated.10,11