Pneumocystis carinii infection presents as common bile duct mass biopsied by fine‐needle aspiration

Abstract

This paper describes a case of Pneumocystis carinii (PC) presenting as a common bile duct intraluminal mass in an HIV

Clue to fine‐needle aspiration diagnosis of pleural pneumocystoma: Neovascularization and Langhans' giant cell reaction

“…Likewise, the radiologist may not consider pneumocystis in an intrathoracic mass lesion. Neovascularization and a histiocytic tissue reaction in an extrapulmonary pneumocystis mass was first reported by Abati et al 6 in aspirates of a splenic and a pleural mass; similar finding was later reported in an aspirate of a mass of the common bile duct, 8 which was also associated with a prominent Langhans' giant cell reaction. Both reports emphasized the importance of recognizing these peculiar cytologic features in aspirates of extrapulmonary pneumocystis masses, especially in patients with AIDS and in individuals of unknown HIV status.…”

“…Both reports emphasized the importance of recognizing these peculiar cytologic features in aspirates of extrapulmonary pneumocystis masses, especially in patients with AIDS and in individuals of unknown HIV status. The cytologic presentation of our case is indistinguishable from that of the common bile duct mass reported previously, 8 with its neovascularization and Langhans' giant cell reaction associated with a massive deposition of pneumocystis organisms appearing as granular exudate.…”

“…As postulated earlier, 8 two possible mechanisms may account for the exuberant blood vessel proliferation in extrapulmonary pneumocystis masses: 1) a tissue-reparative reaction to the massive deposition of Pneumocystis, or 2) angiogenic factors secreted by pathogens. The pneumocystis organisms were phagocytized by Langhans' giant cells derived from the fusion of histiocytes influxed from the newly formed vessels.…”

“…Rare cases have been reported in lymph nodes, bone marrow, pleura, spleen, gastrointestinal tract, liver, common bile duct, pancreas, skin, thyroid, and eye. [2][3][4][5][6][7][8]…”