Role of fine needle aspiration biopsy in the diagnosis and management of malacoplakia.

A case of malacoplakia of the colon and retroperitoneum is presented. The diagnosis was made by both endoscopic biopsy and fine needle aspiration biopsy (FNAB). The response to therapy was monitored by sequential FNAB. The initial biopsy revealed large numbers of bacilli within the histiocytes; these bacilli were markedly reduced in number during successful therapy but reappeared in large numbers when the disease relapsed. It is suggested that FNAB may play a role in both the diagnosis and management of patients with malacoplakia.