Mycobacterial spindle-cell pseudotumor (MSP) is a rare lesion characterized by local proliferation of spindle-shaped histiocytes containing acid-fast positive mycobacteria. The aim of this study is to describe the clinical parameters and treatment outcomes of patients with MSP.
A Pubmed search was conducted using the search terms related to mycobacteria and spindle cell tumors. A previously unreported stem cell transplant recipient from our institution diagnosed with MSP was also included. Demographics, comorbidities, site of infection, treatment, and clinical outcomes were analyzed. Success was defined as clinical and radiologic response. Failure was defined as disease progression and/or death.
Twenty-three patients were reviewed. Two other cases were excluded because of inadequate data. Mean age was 49±2.1 yrs; 20 (87%) patients were males. Ten (43%) had HIV/ AIDS, 4 (17%) had solid organ transplants, 1 had allogeneic stem cell transplant with graft versus host disease, 4 (17%) received immunosuppressive therapy for diseases other than transplant, 2 (9%) had diabetes mellitus, and 2 (9%) did not have any underlying condition. Mycobacterium avium complex was the most frequent organism isolated in 10 (44%), M. tuberculosis in 3 (13%) cases, M. chelonae in 2 (9%), and 1 (4%) each of M. xenopi, M. haemophilum, and M. simiae. The site of infection included skin in 9 (39%), lymph nodes in 5 (22%), intraabdominal organ involvement in 4 (17%), lungs in 3 (13%) and brain in 2 (9%). Five (22%) received antimycobacterial agents, 11 (48%) underwent surgical resection, 3 (13%) received antimycobacterial agents plus surgery, 2 (9%) were not treated, and 2 (9%) lacked information. Treatment was successful in 8 (35%) and failed in 7 (30%); 5 of these 7 died. Antimycobacterial therapy was significantly associated with successful outcome (6/8 vs 1/7; 95% IC [1.14, 43], p=0.001).
MSP is a rare condition associated primarily with immunodeficiencies. Antimycobacterial therapy is significantly associated with successful outcome.
K. Van Besien, None
M. Satlin, Allergan: Grant Investigator , Grant recipient
S. Jenkins, None
L. Westblade, None
T. Walsh, None
C. Small, None