Contributed by Wen-Wei Chung, MD, PhD, William Pasculle, ScDFINAL DIAGNOSIS:
DISSEMINATED TUBERCULOSIS INVOLVING LUNG, GENITOURINARY TRACT, AND MULTIPLE JOINTS INCLUDING RIGHT ELBOW AND LEFT WRIST BY MYCOBACTERIUM TUBERCULOSIS COMPLEX.
DISCUSSION:
This elderly patient developed disseminated mycobacterial infection of the genitourinary tract and skeletal system, which most likely resulted from reactivation of previously-acquired pulmonary tuberculosis. Although he had no previous history of TB, he had worked as a coal miner, which may account for his contracting tuberculosis originally. Other than his age (6), this patient had no other risk factors, such as immunosuppression, for developing disseminated tuberculosis. His previously recognized COPD and cardiac problems most likely complicated the early appreciation of his pulmonary tuberculosis.
Extrapulmonary disease (pleura, lymph nodes, bones, gastrointestinal tract, or urinary tract) is present in 15% of non-HIV patients and up to 70% of HIV positive patients with tuberculosis (1). Bone and joint TB accounts for 10% of all cases of extrapulmonary TB. Two percent of all new cases of TB involve bone or joints. Because musculoskeletal involvement of TB can mimic other more common rheumatic disorders, and because of the potential for disastrous outcomes in cases where the diagnosis is delayed, it is important to recognize the multiple rheumatologic manifestations of TB (2). Five syndromes have been described: spondylitis (Pott' s disease), peripheral arthritis, osteomyelitis, tenosynovitis and Poncet's disease (aseptic inflammatory polyarthritis in the presence of active TB, usually involving the lungs).
TB tenosynovitis is typically an indolent, relapsing process that is difficult to diagnose. This patient had a history of numerous previous rheumatologic complaints, including severe osteoarthritis of the right hip. When he initially developed pains in his wrist and elbow, these were thought to be exacerbation of his previous rheumatologic condition. He was thus treated for gouty arthritis based on initial clinical impression and the presence of urate crystals in joint fluid. In arthroscopic biopsy, however, granulomatous inflammation in tendon sheaths suggestive of TB tenosynovitis, was found. The differential diagnosis of granulomatous inflammation in a tissue specimen include infectious etiologies such as Mycobacterium tuberculosis, atypical mycobacteria, various fungi, Brucella species, and non-infectious etiologies such as sarcoidosis, crystal-associated arthritis, and foreign body reactions. Culture of the appropriate specimens is required to confirm the diagnosis (4).
Most investigators recommend beginning antituberculous or other antimicrobial therapy when granulomats are seen in tissue specimens from patients with tenosynovitis; definitive long-term therapy would then depend on the isolation of mycobacteria from cultures (4). Fortunately, the colony counts of M. tuberculosis within bone, joint, and adjacent soft tissues are at least 1000 times lower than that seen in active pulmonary TB. In addition, musculoskeletal TB is unlikely to be associated with drug-resistant strains (2). Thus, chemotherapy of musculoskeletal TB is usually successful.
Genitourinary TB is the second most frequent form of extrapulmonary TB (3). Renal disease is more frequent than that of the male reproductive organs. Among the genitourinary organs, prostate, seminal vesicle, epididymis and testicle are involved in the order listed. Genital lesions have been reported in 13% of patients with miliary renal lesions, in 52% of those patients with caseating renal lesions and 100% of patients with cavitary renal lesions. These findings suggest that male genital infection usually results from infected urine (3).
Before chemotherapy, surgery was the only available treatment for genitourinary TB. Currently, chemotherapy can be relied on to eradicate infection and surgery is reserved for management of complications or for reconstructive purposes. This patient was treated with four antituberculous agents: Isoniazid, Rifampin, Ethambutol, and Pyrazinamide. Because of the potential liver toxicity of these medications in the elderly, his liver function test results were followed closely on a weekly basis. Although the alkaline phosphatases were slightly elevated, all other liver function test results were within normal limits one month after the commencement of anti-tuberculous treatment. The renal function follow-up was normal.
In conclusion, TB remains one of the leading causes of death in developing countries and its resurgence in developed countries warrants our attention (5, 7). Extrapulmonary TB has a broad spectrum of clinical manifestations that may be referable to almost any organ system and should be considered in the differential diagnosis of bone, joint, genitourinary tract and central nervous system disease. This patient presented with orchitis resistant to antibiotics followed by oligoarthritis, both of which were caused by Mycobacterium tuberculosis Complex.
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Contributed by Wen-Wei Chung, MD, PhD, William Pasculle, ScD
