Extramammary Paget's disease with intracytoplasmic lumen formation

Extramammary Paget's disease (EMPD) is regarded as a malignancy most likely derived from or differentiated into apocrine sweat duct and gland. The tumor cells in EMPD usually have abundant pale cytoplasm and large pleomorphic nuclei. We present a case with EMPD where the tumor included many signet ring cells, cells with intracytoplasmic lumen formation and glandular formation. This case is interesting in that the tumor included many cells with intracytoplasmic lumen formation. Signet ring cells and glandular formation support the traditional speculation that EMPD is derived from apocrine sweat gland and intracytoplasmic lumen formation may mimic the intrafollicular apocrine duct.