Rare primary pulmonary mucosa-associated lymphoid tissue lymphoma misdiagnosed with tuberculosis: A case report.

RATIONALE: Primary pulmonary mucosa-associated lymphoid tissue lymphoma (MALToma) is a rare subtype of non-Hodgkin lymphoma with a relatively low incidence rate clinically. Atypical clinical symptoms and nonspecific chest computed tomography features of the disease make it difficult to determine and treatment is delayed. We discuss the diagnosis and treatment of a patient with primary pulmonary MALToma to raise clinicians' awareness of this condition. PATIENT CONCERNS: A 66-year-old male patient with a medical history of tuberculosis has been experiencing progressive exacerbation of respiratory symptoms and nonresponsive treatment without an unclear diagnosis for 5 years. He was transferred to our hospital because a nonspecific soft tissue mass in the right upper lobe of the lung was found on his chest computed tomography. Laboratory results with serum immunofixation electrophoresis showed polyclonal immunoglobulin (Ig) G, IgM, IgA, and λ-light chain on admission. DIAGNOSIS: Pathological examination and immunohistochemical staining of lung biopsy revealed a definitive diagnosis of pulmonary MALToma with stage IV. INTERVENTIONS AND OUTCOMES: The patient received immunotherapy with anti-CD20 monoclonal antibody (rituximab), and showed significant clinical improvement at the 6-month follow-up. CONCLUSIONS AND LESSONS: Diagnosis of primary pulmonary MALToma mainly relies on histopathological examination, and comprehensive laboratory examinations are also necessary. Clinicians should combine laboratory tests (such as immunofixation electrophoresis in our case) to assist in medical diagnosis in cases of atypical clinical manifestations and imaging characteristics. Immunotherapy appears to be the main treatment protocol for advanced patients.

Right time to detect urine iodine during papillary thyroid carcinoma diagnosis and treatment: A case report.

BACKGROUND: This is the first documentation of a spontaneous and nonspecific chemical reaction of an iodinated contrast media with ammonium persulfate used in As3+-Ce4+ catalytic spectrophotometry for urine iodine concentration (UIC) detection. CASE SUMMARY: We herein report an incidental case who had a dual source computed tomography examination for papillary thyroid carcinoma diagnosis. Serial spot urine specimens were collected during her hospitalization and were measured by As3+-Ce4+ catalytic spectrophotometry on a Beckman Coulter AU5800. The reacted solutions were "brownish", and the results showed extremely high iodine concentrations despite serial dilutions. The patient claimed no dietary habit of iodized salt or iodine-containing medical history, which strongly pointed to iodinated contrast media (ICM) via intravenous injection. Even with 0.01% ICM, its interruption is still profound on the desired urine iodine reaction with ammonium persulfate, leading to inaccurate UIC and possibly inappropriate treatment. CONCLUSION: The following laboratory suggestions should be considered: (1) As3+-Ce4+ catalytic spectrophotometry is only suitable for UIC measurement after confirmed ICM renal clearance; (2) A mass spectrometry-based method can be applied as an alternative during the ICM clearance period; and (3) The UIC baseline can be confirmed after ICM injection by consecutive detection for at least 2 mo.

High Uric Acid (UA) Negatively Affects Serum Tartrate-Resistant Acid Phosphatase 5b (TRACP 5b) Immunoassay.

BACKGROUND: Bone metastases often occur in the majority of patients with advanced cancer, such as prostate cancer, lung cancer and breast cancer. Serum tartrate-resistant acid phosphatase 5b (TRACP 5b), a novel bone resorption marker, has been used gradually in the clinics as a specific and sensitive marker of bone resorption for the early diagnosis of cancer patients with bone metastasis. Here, we reported that high concentrations of uric acid (UA) lead to decrease of TRACP 5b levels and determined whether TRACP 5b level was associated with UA in interference experiment. METHODS: A total of 77 patients with high concentrations of UA and 77 healthy subjects were tested to evaluate the differences in their TRACP 5b levels. Serial dilutions of UA were respectively spiked with a known concentration of TRACP 5b standard sample, then Serum TRACP 5b was detected by using bone TRAP® Assay. A correction equation was set to eliminate UA-derived TRACP 5b false-decrease. The effect of this correction was evaluated in high-UA individuals. RESULTS: The average TRACP level of the high-UA individuals (1.47 ± 0.62 U/L) was significantly lower than that of the healthy subjects (2.62 ± 0.63 U/L) (t-test, p < 0.0001). The UA correction equation derived: ΔTRACP 5b = -1.9751lgΔUA + 3.7365 with an R2 = 0.98899. Application of the UA correction equation resulted in a statistically non-significant difference in TRACP 5b values between the healthy subjects and high-UA individuals (p = 0.24). CONCLUSIONS: High UA concentrations can falsely decrease TRACP 5b levels due to a method-related systematic error. To avoid misdiagnoses or inappropriate therapeutic decisions, increased attention should be paid to UA interference, when TRACP 5b is used for early diagnosis of cancer patients with bone metastasis, evaluation of the aggressiveness of osteosarcoma or prediction of survival in prostate cancer and breast cancer with bone metastases.

Diagnostic value of cystatin C and glomerular filtration rate formulae in Chinese nonelderly and elderly populations.

BACKGROUND: Serum cystatin C has been recognized as a surrogate marker for serum creatinine (SCr). However, whether cystatin C and cystatin C-based glomerular filtration rate (GFR) formulae offer any diagnostic value in nonelderly and elderly subjects has rarely been investigated. METHODS: Reference GFR (rGFR) values were established using the 99mTc-DTPA renal dynamic imaging method. Nine GFR formulae were used to predict estimated GFR (eGFR). RESULTS: A total of 534 Chinese participants were enrolled. Cystatin C had a better diagnostic value than SCr. The superiority of cystatin C was more distinctly observed in the elderly. Combined cystatin C and SCr gave similar diagnostic values to cystatin C alone (p>0.05). Compared with single markers, GFR prediction formulae improved accuracy. Each formula had its own characteristics and applicability. Most formulae predicted with higher accuracy in the elderly than they did in the nonelderly. In chronic kidney disease (CKD) stage 1, the CKD-EPI formula had the least bias and the highest accuracy for the nonelderly, while the Hojs and Ma formulae performed best for the elderly. In the CKD stage 2-3, the Macisaac formula gave the most accurate eGFR. In the CKD stage 4-5, it was the CG formula that gave the closest estimate to the rGFR. CONCLUSIONS: Cystatin C could be superior to SCr, particularly in the elderly; however, cystatin C formulae and SCr formulae may possess their own applicability in different CKD stages and age groups. At present, it is not possible to say that cystatin C formulae are superior to SCr formulae.

Are cystatin C-based equations superior to creatinine-based equations for estimating GFR in Chinese elderly population?

PURPOSE: Cystatin C has been proposed as a surrogate marker of kidney function. The elderly population accounts for the largest proportion of chronic kidney disease (CKD) patients. The aim of this study was to assess the diagnostic value of serum cystatin C and compare the applicability of cystatin C-based equations with serum creatinine (Scr)-based equations for estimating glomerular filtration rate (GFR). METHODS: The estimated GFR (eGFR) values from six cystatin C-based equations (Tan, MacIsaac, Ma, Stevens1-3) and three Scr-based equations (CG, MDRD, CKD-EPI) were compared with the reference GFR (rGFR) values from 99mTc-DTPA renal dynamic imaging method. RESULTS: A total of 110 elderly Chinese (60-92 year, 71.05±7.62 year) were enrolled. Cystatin C had better diagnostic value than Scr (relationship coefficient with rGFR: cystatin C -0.847 vs. Scr -0.729, P<0.01; sensitivity: cystatin C 0.90 vs. Scr 0.55, P<0.01; AUCROC: cystatin C 0.857 vs. Scr 0.757, P<0.01). All the equations predicted GFR more accurately for rGFR≥60 ml/min/1.73 m2 than for rGFR<60 ml/min/1.73 m2. Most equations had acceptable accuracy. The cystatin C-based equations deviated from rGFR by -12.78 ml/min/1.73 m2 to -2.12 ml/min/1.73 m2, with accuracy varying from 64.6 to 82.7%. The Scr-based equations deviated from rGFR by -5.37 ml/min/1.73 m2 to -0.68 ml/min/1.73 m2, with accuracy varying from 77.3 to 79.1%. The CKD-EPI, MacIsaac and Ma equations predicted no bias with rGFR (P>0.05), with higher accuracy and lower deviation in the total group. The MacIsaac, CKD-EPI and Stevens3 equations could be optimal for those with normal and mildly impaired kidney function, whereas the Ma equation for those with CKD. CONCLUSION: Cystatin C is a promising kidney function marker. However, not all cystatin C-based equations could be superior to the Scr-equations.