Deciphering Histoplasmosis, Systemic Noncaseating Granuloma,

at Bletchley Park, north of London, where it had been moved from Whitehall as a safety precaution, to participate in the project code-named "Ultra," with the objective of decrypting radio trans¬ missions generated and read by an electromechanical device, "Enig¬ ma," comprising five rotors and a plugboard of such baffling sophistication and complexity (there were 1.3X1012 plugboard combinations for each of 1.1X105 rotor states) that the Germans, throughout the war, and despite compelling evidence to the con¬ trary, believed it to be indecipherable. Decryption depended on the use of "cribs" such as duplicate messages and standard forms of address, and "Bombes," computers exploiting the theoretical con¬ cepts embodied in the Turing Universal Machine. Validation re¬ quired the achievement of "plaintext." The remarkable success of Ultra, which led to the Allies' victorious prosecution of the subma¬ rine war in the Atlantic, remained the most closely guarded secret of WWII; its existence was not revealed until 25 years later.1 If obliged to decrypt the enigmatic literature on histoplasmosis accompanied by SNG, it is a fair bet that the Bletchley Park staff w^ould have employed similar methods. Carter and Hunninghake (July 1997)2 infer that their patient with SNG had a pauci-bacillaiy form (no organisms were identified from any site) ofprogressive disseminated histoplasmosis (PDH) based on exposure, nondiagnostic serologic titers, and calcified hilar lymph nodes. Does dense lymph node calcification develop within this timeframe? Could the enlargement have been due to sarcoid granuloma superimposed on previously calcified nodes? Were ear¬ lier films available for comparison? Excepting the massive pleural effusion and calcified lymph nodes, their patient resembles 11 persons described by Wheat et al,3 with SNG accompanying serologically confirmed histoplasmosis in an endemic area (Indianapolis). In about half, a diagnosis of sarcoidosis preceded by many years an acute exacerbation ascribed to histoplasmosis; in the remainder, the