Subcutaneous endometriosis diagnosed by fine needle aspiration cytology

The fine needle aspiration cytology (FNAC) of two patients manifesting cutaneous/subcutaneous endometriosis is presented. Endometrial tissue sampled by the aspiration technique manifested different cytologic characteristics as compared to those of endometrial tissue obtained by standard exfoliative methods. A primary difference was the appearance of the endometrial cells in syncytial clusters in the aspirate, in contrast to the three-dimensional clusters seen in exfoliated material. These cases emphasize the need to include endometriosis in the differential diagnosis of palpable lesions of the abdominal wall, especially in women with healed surgical scars, and the role of FNAC in diagnosing such lesions.