Tuberculous pseudotumor causing biliary obstruction. Report of a case with diagnosis by fine needle aspiration biopsy and bile cytology.

Hepatobiliary tuberculosis is a rare but distinct clinical entity. We report an unusual case of biliary tract obstruction due to localized hepatic tuberculosis with periportal tuberculous adenitis. The lesion mimicked a malignancy clinically and radiologically. Fine needle aspiration biopsy revealed granulomas, epithelioid histiocytes and Langhans' giant cells. The cytodiagnosis was confirmed by identification of acid-fast bacilli in the bile cytology and isolation of Mycobacterium tuberculosis by culture. The patient responded to antituberculosis therapy. The usefulness of bile cytology in the diagnostic management of biliary tract obstruction is illustrated.

Crystal structure and solid-state behavior of aspirin anhydride crystals.

The crystal structure and solid-state behavior of aspirin anhydride were determined using single-crystal X-ray techniques and microscopic examination of the reacting crystals. The crystal structure and solid-state conformation of aspirin anhydride were similar to those of related compounds. The crystal packing of aspirin anhydride allows the initial product of the solid-state reaction to be predicted; however, this prediction could not be tested because the thermal degradation products reported in the literature appear to be those obtained from reaction in a liquid state.