A 48-yr-old man was admitted with a 1-month history of fever and a 2-week history of dyspnea on exertion at Severance Hospital in Seoul, Korea. He had a history of myelodysplastic syndrome (MDS) diagnosed 21 months ago prior to admission and had been treated with oral glucocorticoid (prednisolone, 10 mg daily) with regular follow-up. A year after MDS was diagnosed, multiple erythematous tender nodules developed on both lower legs, and a skin biopsy of the calf revealed Sweet's syndrome. He continuously had these skin lesions without complete resolution until admission. On admission, several papulonodular skin lesions on his arms, chest, back, abdomen, buttocks, and legs were noted (Fig. 1). Multiple LNs were palpated on the medial side of the right thigh and left cervical area. Initial laboratory tests showed leukopenia with a white blood cell count of 1,950/microL; severe anemia with a Hb level of 6.8 g/dL; mild thrombocytopenia with a platelet count of 113,000/microL; an elevated ESR (73 mm/hr) and C-reactive protein level (10.8 mg/dL). Chest computer tomography (CT) confirmed multiple LNs enlargement at the mediastium, paratracheal area, subcarina and right perihilar bronchovascular interstitial and interlobular septal thickening. Initially, sputum AFB smears revealed a negative finding. Meanwhile, both excisional LN biopsies, which were performed at the palpable LNs of the thigh and neck, and skin and mediastinoscopic paratracheal LN biopsies revealed necrotizing granuloma with many AFB. Also, an AFB smear of a pus-like discharge obtained from the paratracheal LN revealed a positive finding.
With a presumptive diagnosis of disseminated tuberculosis, anti-tuberculosis therapy was started with HERZ (isoniazid [INH], rifampin [RFP], ethambutol [EMB], and pyrazinamide [PZA]) regimens on hospital day (HD) 16. However, as the skin lesions progressed rapidly and high spiking fever persisted despite HERZ treatment, we assumed he had a rapidly growing NTM such as M. Abscessus or M. fortuitum, and started him on amikacin, clarithromycin, levofloxacin and cefoxitin instead of EMB and PZA. However, improvement of the skin lesions was not evident.
Three weeks after anti-tuberculosis therapy was started, a mycobacterium culture of skin and pus-like discharge obtained from the paratracheal LN revealed NTM, and repeated sputum mycobacterium culture also revealed NTM. At HD 43, all NTMs cultured in sputum, paratracheal LNs, and skin were identified as M. kansasii by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the polymorphic region of the rpoB gene. In vitro drug susceptibility testing of M. kansasii showed that the isolate was susceptible to RFP, EMB, PZA, streptomycin, moxifloxacin, and cycloserine but resistant to INH and para-aminosalicylic acid. At HD 43, we altered the anti-mycobacterial treatment regimens to INH, RFP, EMB, and clarithromycin.
Gradual improvement of the general condition and symptoms with regression of skin lesions was noted. Sputum AFB, which was examined at HD 51, was converted into negative and mycobacterial culture of sputum did not identify any mycobacteria. However, during treatment for M. kansasii, the patient developed small bowel obstruction and ischemic colitis. Although he underwent a small bowel resection and intensive conservative management, the patient died on HD 121.