TUBERCULOSIS AND ACUTE LEUKAEMIA

CASE : A 73-year-old male, a non -smoker, presented on December 28. 1979, with a sixweek history of malaise. 13 kg weight loss. and non-productive cough. He had developed a fever the night before admission. There was no past or family history of tuberculosis. Physical examination revealed a temperature of 38" C, and decreased air entry was evident in both lungs. with diffuse bilateral crepitations. There were no other physical signs. Full blood count revealed: Hb 66g/L; WCC 23.3 x 10' /L; differential blast cells 16%, promyelocytes 1 %. myelocytes 3%. neutrophils 3%. lymphocytes 14%, monocytoid cells 63%; platelets 115 x 10'/L; and ESR over 140 mm in one hour. Bone marrow aspiration showed unequivocal acute myelomonocytic leukaemia with gross hypercellularity, and over 80% blast cells, most of which appeared myelomonocytic. many of them with Auer rods. Chest X-ray examination revealed diffuse air space opacification in both lungs, particularly in the upper zones. The picture was consistent with active tuberculosis. No previous films were available for comparison. Pseudomonas aeruginosa was grown in one of his' blood culture bottles. A Mantoux test was negative. Only small amounts of purulent sputum were available for culture. However. an atypical mycobacterium was grown on two separate days, 14 days apart, the identification being that of the Mycobacterium mais group. a scotochromogen, Runyon group II. M. terrae was also grown in one culture bottle on another occasion. An unusual feature of this organism was its sensitivity not only to rifampicin and ethambutol, but also to capreomycin and prothionamide. The patient was treated with cytosine arabinoside and thioguanine, together with gentamicin. carbenicillin . rifampicin. ethambutol and INH. However. he deteriorated slowly. and the marrow appearance showed no decrease in blast cells. Although the radiological appearance of his lungs improved slowly over this period. he died with acute renal failure on February 18. 1980. No mycobacteria were grown from postmortem lung cultures. and none were seen microscopically. It has been reported that infection with Runyon group" scotochromogens is more common in some areas than are infections with M. tuberculosis. 3 and that these organisms have even produced disseminated disease in patients with haematological disorders. on rare occasions. 4 The distinction between leukaemia and leukaemoid reactions is difficult,' 6 6 and myeloblasts with Auer rods have been reported in one case. Whether this case represents a new infection, or reactivation, in a compromised host. could not be established. In this patient the diagnosis of acute leukaemia has not been in doubt, and the clinical picture, together with the radiological appearance and the isolation of the mycobacteria on two separate occasions, lead us to conclude that this was active pulmonary tuberculous infection occurring simultaneously with acute myelomonocytic leukaemia.