Case report: retroperitoneal aspergilloma in a patient with rheumatoid arthritis presenting as malignant tumor.

BACKGROUND: Aspergillosis in patients with impaired immunity usually presents with invasive pulmonary infection and dissemination to a variety of organs via hematogenous spread. Aspergilloma in the retroperitoneal cavity is a rare disease with only a few cases reported in the literature. To the best of our knowledge, the present case of a retroperitoneal aspergilloma with no surgical history is only the second report in the literature. CASE PRESENTATION: A 65 year-old man, who had been receiving immunosuppressive treatment for rheumatoid arthritis with vasculitis for 9 years, was referred to the Urology Department with a retroperitoneal mass. This was confirmed by computed tomography performed during treatment for pulmonary aspergilloma. Because it was not possible to rule out malignant disease (e.g., liposarcoma), surgical exploration was performed. Pathological examination revealed aspergillus hyphae with fat necrosis, and retroperitoneal aspergilloma was diagnosed and appropriately treated. The tumor did not recur subsequently. CONCLUSION: Our present case emphasizes that pharmacological treatments for aspergilloma in the retroperitoneal cavity have poor drug transitivity, so the relative effectiveness of pharmacological response is not useful for differentiating retroperitoneal aspergilloma from malignant disease.

Neutrophil CD64 is upregulated in RA patients with lymphoma but not in other solid cancers.

OBJECTIVE: To evaluate the utility of quantifying CD64 expression on neutrophils in rheumatoid arthritis patients with malignancy, especially its diagnostic role in lymphoma. METHODS: We used flow cytometry to quantify CD64 expression on neutrophils from patients diagnosed with malignancy during the follow-up period prior to initiating treatment. RESULTS: Neutrophils from 18 patients with lymphoma expressed significantly higher levels of CD64 (9635.6 ± 2123.7 molecules/cell) than those from 32 patients with other solid cancers (carcinoma) (1250.5 ± 91.1 molecules/cell) (p < 0.001). When the cutoff value was set at 2060 molecules/cell, the sensitivity and specificity of CD64 for diagnosing lymphoma was 88.9% and 94.4%, respectively. CONCLUSIONS: The quantitative measurement of neutrophil CD64 by flow cytometry may be useful as a subsidiary diagnostic marker in patients with suspected lymphoma. Although neutrophil CD64 is currently a well-known marker of infection, it is necessary to bear in mind that lymphoma is also a candidate in differential diagnosis when CD64 expression on neutrophils is upregulated.

Neutrophil CD64 for monitoring the activity of nontuberculous mycobacteria infection in patients with rheumatoid arthritis.

OBJECTIVE: To evaluate the utility of neutrophil CD64 as a marker for monitoring the activity of nontuberculous mycobacteria (NTM) infection in patients with rheumatoid arthritis (RA). METHODS: We compared neutrophil CD64 expression in nine RA patients with NTM infection in the active and inactive phase of NTM disease chronologically. "Active phase" was here defined as present in patients admitted to hospital to receive intensive treatment for NTM, as well as outpatients with an infectious episode showing positive acid- and alcohol-fast bacillus (AFB) staining of sputa (Grade 2-3) who needed to start treatment for NTM with a multiple antibiotics regimen. The cut-off value for CD64 positivity was 2000 molecules/cell. RESULTS: Neutrophils from patients with active-phase NTM infection expressed high levels of CD64 with a mean ± SEM of 7335 ± 784 molecules/cell. However, during the inactive phase of disease, this was significantly lower (1481 ± 103 molecules/cell, p < 0.001). The sensitivity and specificity of neutrophil CD64 to detect active-phase NTM infection was 96.3% and 84.6%, respectively. Expression of neutrophil CD64 was not affected by disease activity of the RA itself. CONCLUSIONS: Neutrophil CD64 is useful for monitoring disease activity in NTM infection of patients with RA.