Cell block preparation – An adjunct to fine-needle aspiration cytology – unveiled the diagnosis

Endometriosis is defined as the presence of functioning endometrium outside the uterus. Scar endometriosis is a rare entity reported in 0.03%–1.7% of women following cesarean section scars. The diagnosis is frequently made only after excision of the diseased tissue. We present a case of 28-year-old female who presented with mass on anterior abdominal wall adjacent to a previous surgical scar. Fine-needle aspiration cytology (FNAC) of the mass revealed sheets of epithelial cells, spindle-shaped cells, and hemosiderin-laden macrophages suggestive of endometriosis. Additional cell block preparation done with the aspirate material confirmed the diagnosis. The present case highlights the use of cell block preparation together with FNAC which consecutively helps in preoperative diagnosis of scar endometriosis and facilitates the best management strategy.