Cytodiagnosis and comparison of nondecidualized and decidualized endometriosis of the abdominal wall. A report of two cases.

We describe two cases of endometriosis of the abdominal wall occurring in young, multiparous women in which the diagnosis was made by fine needle aspiration biopsy. One case illustrates the cytologic features of non-decidualized endometriosis: a biphasic population of stromal and glandular cells. In contrast, the other case showed large, plump stromal cells in a distinctive myxoid background, creating a picture of decidualized endometriosis. The differential diagnoses of palpable masses in the abdominal wall and the importance of clinicopathologic correlation are discussed.