Infarction after fine needle aspiration. A report of four cases.

BACKGROUND: Fine needle aspiration (FNA) is a well-established and safe method for the rapid diagnosis of palpable and deep-seated masses. A few clinically important complications, including bleeding, pneumothorax, infection and inflammatory reactions, result from FNA. Little attention has been focused on tissue changes resulting from FNA. In a small number of cases FNA has been followed by varying degrees of necrosis. This has occurred in thyroid nodules, salivary glands, breast fibroadenomas, lymph nodes and renal cell carcinoma.

CASES: Four cases of infarction followed FNA biopsy. All 4 (1 papillary carcinoma of the thyroid, 1 pleomorphic adenoma of the parotid gland and 2 fibroadenomas of the breast) were diagnosed by FNA. Subsequent histologic study of the surgical specimens revealed massive necrosis of the neoplasms.

CONCLUSION: Necrosis associated with infarction may cause diagnostic problems in two settings. FNA yielding necrotic debris may result in a false negative diagnosis in repeat aspiration. Alternatively, post-FNA infarction may obscure the nature of a neoplasm diagnosed by FNA, making histologic confirmation difficult.