Venous Thromboembolism: Role of the Clinical Laboratory in Diagnosis and Management.

BACKGROUND: Venous thromboembolism (VTE) is the third most common cause of cardiovascular illness and is projected to double in incidence by 2050. It is a spectrum of disease that includes deep venous thrombosis (DVT) and pulmonary embolism (PE). In February 2016, the American College of Chest Physicians provided updated management guidelines for DVT and PE to address some of the unresolved questions from the previous version and to provide recommendations related to newer anticoagulants. CONTENT: Here we review current concepts for screening, diagnosis, thromboprophylaxis, and management of DVT and PE. We also describe the management of VTE in acute, long-term, and extended phases of treatment. Thrombophilia testing is rarely necessary and should be used judiciously; the laboratory can serve an important role in preventing unnecessary testing. The direct oral anticoagulants are as effective as conventional treatment and are preferred agents except in the case of cancer. The initial management of PE should be based on risk stratification including the use of D-dimer testing. Thrombolysis is used in cases of hemodynamically unstable PE and not for low-risk patients who can be treated on an outpatient basis. SUMMARY: This review is intended to provide readers with updated guidelines for screening, testing, prophylaxis, and management from various organizations.

Characterization of bilirubin interference in three commonly used digoxin assays.

BACKGROUND: Due to the narrow therapeutic range of digoxin, determining serum/plasma digoxin concentrations is critical for assessing patients with congestive heart failure, atrial fibrillation, and certain types of arrhythmias. However, digoxin quantification by competitive immunoassays is susceptible to interferences that may alter the accuracy of its measurement in patient plasma. This study aimed to characterize the extent of bilirubin interference in three commonly used digoxin immunoassays. METHODS: Digoxin concentrations were compared using the Beckman Coulter® Unicel DxI 800, the Vitros® 4600, and the Roche Cobas® 8000 in neat or digoxin-spiked icteric and non-icetric plasma samples. A mixing study was performed to demonstrate how digoxin quantification is affected by bilirubin. An equation was derived that predicts the response of the DxI 800, given known bilirubin and digoxin concentrations. RESULTS: The DxI reported detectable concentrations of digoxin in high bilirubin samples with no added digoxin, while the Vitros® 4600 and Cobas® 8000 gave virtually undetectable results. Spiking digoxin into samples with elevated bilirubin concentrations resulted in a higher percent recovery for the DxI 800 when compared to the other two platforms. The mixing study also revealed an increase in the percent recovery in the DxI 800, while the Vitros® 4600 and Cobas® 8000 were comparable to the expected concentration of digoxin. CONCLUSIONS: The DxI 800 is most prone to interference by bilirubin, while the Vitros® 4600 and Cobas® 8000 are relatively unaffected. Icteric samples should be interpreted with caution if digoxin quantification is needed, especially on the DxI 800 assay.

Transfusion-associated chest pain.

BACKGROUND: Chest pain is a common clinical dilemma and is rarely reported as part of suspected adverse events in transfusion recipients. The aim of this study is to describe and characterize the clinical presentation of transfusion-associated chest pain and how it relates to currently defined National Healthcare Safety Network hemovigilance entities. STUDY DESIGN AND METHODS: This is a retrospective chart review at a single large academic institution of patients who reported chest pain during or after a transfusion that resulted in a transfusion reaction investigation during the period January 2004 to December 2016. RESULTS: Of approximately 500,000 transfusions occurring during the study period and 3220 suspected transfusion reactions reported, 23 (0.7%) reactions involving chest pain were identified, of which 20 had medical records available for analysis. Ninety percent of cases presented with chest pain within 2.5 hours of the start of transfusion, with a mean time of onset of 92.2 minutes. Fourteen RBC units and 6 platelet units were implicated, and all transfusions were ABO identical. All posttransfusion workups were negative for hemolysis or agglutination on direct antiglobulin testing. Twenty percent of cases showed evidence of acute coronary ischemia that was first detected during transfusion with rising troponins or electrocardiographic abnormalities, all in association with RBC transfusion for anemia. For most reactions, the signs and symptoms did not fit any hemovigilance definitions for transfusion reactions. CONCLUSION: Chest pain is an infrequently reported chief complaint for transfusion reactions. Increased circulatory volume due to transfusion may be an important contributor to myocardial demand ischemia in at-risk patients. Additional studies are necessary to determine the clinical significance of chest pain during transfusion and to elucidate potential mechanisms.

PAX8-Positive B-Cell Lymphoma in Adrenal Gland Masquerading as Metastatic Renal Cell Carcinoma.

Extranodal lymphomas involve adrenal glands as a mass lesion in 3% to 5% of cases as identified by imaging studies. Definitive diagnosis of the neoplasm is provided by morphological and immunophenotypical evaluation on limited tissue obtained by fine needle aspiration or core biopsy. We report a diagnostically challenging case that presented as masses involving adrenal gland and lung in the setting of a concurrent primary renal cell carcinoma. PAX8, a frequently used marker for renal cell carcinoma, was immunoreactive in the neoplastic cells of the adrenal mass, and thus highly suggestive for metastatic renal cell carcinoma. The neoplasm was eventually proven to represent PAX8-positive diffuse large B-cell lymphoma after extended immunohistochemical workup. This case of unusual presentation of synchronous renal cell carcinoma and adrenal lymphoma with overlapping PAX8 immunoreactivity serves as a potential diagnostic pitfall with significant clinical implications.

Primitive Neuroectodermal Tumor and Wegener's Granulomatosis of the Kidney: A Curious Combination of Two Rare Entities.

Wegener's granulomatosis (WG) is characterized by necrotizing polyangiitis involving the respiratory tract and kidneys. It causes segmental necrotizing glomerulonephritis in the kidneys. In rare cases, a renal pseudotumor may be seen because of the granulomatous process. Association of WG with renal malignancy, however, is very uncommon. We report a case of a patient who presented several years after being treated for WG with malignant hypertension and an infiltrating mass in the right kidney. The histopathology of radical nephrectomy specimen showed presence of primitive neuroectodermal tumor (PNET). Association of renal cell carcinoma (RCC) with WG has been documented in a few cases, but PNET in such circumstances has not been reported. Long-term immunosuppressive treatment is a known risk factor in the development of malignancies, so it is proposed that the occurrence of RCC in WG may have been a side effect of cyclophosphamide treatment. It is not clear whether the same mechanism for PNET holds true in the present case. It is important to make a differential diagnosis between true malignancy and pseudotumors in WG as these entities cannot be distinguished based solely on imaging. We suggest a need to routinely screen the WG patients for increased risk of urologic malignancies.

Laboratory Utilization and Analytical Validation of Fecal Electrolyte Tests.

BACKGROUND: Chronic diarrhea can be categorized as fatty, watery, or inflammatory. Watery diarrhea is further divided into secretory or osmotic types and can be differentiated by measuring fecal electrolytes and osmotic gap. However, with widespread use of endoscopy, it is unclear if these measurements are being used clinically. Furthermore, because stool is not a validated specimen type for Food and Drug Administration-approved electrolyte assays, utilization is a practical concern for laboratories before analytical validation. Here, we determined the clinical utility and validated the performance characteristics of stool electrolytes on the Beckman Coulter AU680. METHODS: Historical results and literature review were used to determine the clinically relevant ranges for stool electrolytes (Na+, Cl-, K+, phosphate, and Mg2+). Additionally, medical chart review was performed (n = 44 patients) on results to evaluate their clinical utility in chronic diarrhea work-up. Linearity, precision, and stability studies were performed on the AU680. Accuracy was evaluated by comparing results to the Roche Cobas 6000 c501. RESULTS: For all cases, stool electrolytes and osmotic gap proved valuable in chronic diarrhea work-up. The imprecision of the assays ranged from 0% to 5.9%. All assays were found to be linear within the instrument's analytical measurement range with appropriate slopes and intercepts. The bias between the AU680 and the Roche c501 ranged from -0.48 to 2.39 (mmol/L or mg/dL). Na+, Cl-, and K+ were stable refrigerated for 5 days and up to 1 freeze-thaw cycle. Phosphate and Mg2+ were stable refrigerated for 48 h, but unstable to freeze-thaw cycles. CONCLUSIONS: Stool osmotic gap is valuable for evaluating chronic diarrhea and can be calculated using electrolyte concentrations measured on the AU680.

Utility of a triple antibody cocktail intraurothelial neoplasm-3 (IUN-3-CK20/CD44s/p53) and α-methylacyl-CoA racemase (AMACR) in the distinction of urothelial carcinoma in situ (CIS) and reactive urothelial atypia.

Urothelial carcinoma in situ (CIS) is a prognostically and therapeutically significant lesion with considerable morphologic overlap with reactive conditions especially in the setting of prior therapy. Various markers including CK20, CD44s, and p53 have been used as an adjunct in making this distinction; however, the utility of these markers in the posttreatment scenario is not fully established. α-Methylacyl-CoA racemase (AMACR) is a tumor-associated marker that is expressed in a subset of high-grade urothelial carcinomas but has not been studied in CIS. This study was undertaken to evaluate the immunoreactivity of CK20, CD44s, and p53 as a triple antibody cocktail intraurothelial neoplasm-3 (IUN-3) in distinguishing CIS from its mimics and to compare its utility with AMACR in the diagnosis of CIS. A total of 135 specimens (7 benign ureters and 128 bladder biopsies-28 reactive, 33 posttherapy reactive, 43 CIS, 24 CIS posttherapy) were included in this study. Immunostaining for p53 (brown, nuclear), CD44s (brown, membranous), and CK20 (red, cytoplasmic and membranous) was performed as a cocktail, and the staining pattern was further classified as: malignant (full-thickness CK20 and/or full-thickness p53 with CD44s negativity), reactive/benign (CK20 limited to the umbrella cell layer, p53 negative, and CD44s positivity ranging from basal to full thickness), and indeterminate (CK20 and p53 positive but not full thickness and/or CD44s positive). AMACR staining was performed in 50 cases. Cytoplasmic staining for AMACR was graded as negative (absent to weak focal staining [<5% cells]) and positive (≥5%). The "IUN-3 malignant" pattern was observed in 84% of cases of CIS without a history of prior therapy and in 71% of the cases of CIS with a history of prior therapy. Cases with posttherapy reactive atypia showed an "IUN-3 reactive" pattern in 84% cases and "IUN-3 indeterminate" pattern in 16% of the cases; the IUN-3 malignant pattern was not identified in any of the cases. Benign and reactive urothelium (with and without a history of therapy) showed an IUN-3 reactive pattern and negative AMACR staining in all the cases (100%). AMACR positivity was observed in 78% of nontreated CIS cases and 50% of CIS posttherapy cases. In these cases, the IUN-3 cocktail showed an IUN-3 malignant pattern in 83% of untreated CIS cases and 88% of CIS posttherapy cases. AMACR positivity is a potentially useful marker of CIS. However, the IUN-3 malignant pattern is a more reliable indicator of CIS compared with AMACR, especially in the posttreatment setting. The simultaneous evaluation of all 3 markers (p53, CD44s, and CK20) in a single slide in the form of a cocktail is advantageous, especially in small biopsy specimens.

Immunohistochemical profile to distinguish urothelial from squamous differentiation in carcinomas of urothelial tract.

Urothelial neoplasms with squamous morphology raise the differential diagnosis between pure primary squamous cell carcinoma, urothelial carcinoma with squamous differentiation and secondary involvement by squamous cell carcinoma, for example, from uterine cervix. Accurate identification between these entities is critical due to differing prognosis and therapeutic strategies. We evaluated the utility of an immunohistochemical panel of 3 urothelial-associated antibodies (uroplakin III, S100P, and GATA3) and two squamous-associated antibodies (CK14 and desmoglein-3) in 50 primary urothelial neoplasms: 15 pure urothelial carcinomas, 12 pure squamous cell carcinomas and 23 urothelial carcinomas with squamous differentiation. Squamous differentiation was defined by intercellular bridges or evidence of keratinization. Pure squamous cell carcinomas were positive for CK14 (100%) and desmoglein-3 (75%), negative for GATA3 and uroplakin III; one case was S100P positive (9%). Pure urothelial carcinomas had an opposite pattern and were positive for S100P (93%), GATA3 (93%), and uroplakin III (67%) and were negative for desmoglein-3; CK 14 was positive in 27% of cases; 74% of urothelial carcinomas with squamous differentiation had expression of urothelial and squamous associated markers (S100P, 83%; GATA3, 35%; uroplakin III, 13%; CK14, 87%; and desmoglein-3, 70%), although reactivity for individual markers within some tumors did not always correspond with morphologic differentiation. Of the remaining 26%, 4 showed an overall "squamous" immunoprofile, whereas 2 cases showed a "urothelial" immunoprofile. Our study showed that a panel of five antibodies identifies squamous and urothelial differentiation in most instances suggesting potential diagnostic utility.

Ki-67 proliferative index predicts progression-free survival of patients with well-differentiated ileal neuroendocrine tumors.

Ki-67 proliferative index (Ki-67 index) is suggested to be an important prognostic variable and is included as one of the grading parameters for neuroendocrine tumors. The present study was undertaken to determine the usefulness of the Ki-67 index and the corresponding tumor grade in predicting progression-free survival (PFS) of patients with ileal well-differentiated neuroendocrine tumors (wNETs). Tumors from 57 patients with ileal wNETs were studied. Immunohistochemical staining for Ki-67 was performed on the primary as well as selected metastatic tumors and quantitated by computer-assisted image analysis using the Ariol system. The tumors were graded based on mitotic activity and Ki-67 index. Clinical and pathological variables affecting the PFS were analyzed. There were 29 women and 28 men, with a mean age of 59 years. At the time of initial presentation, 8 patients (14%) had localized disease (stages I and II), 29 patients (51%) had regional (nodal/mesenteric) spread (stage III), and 20 patients (35%) had distant metastasis (stage IV). Twelve patients experienced disease progression during subsequent follow-up. Patients with initial stage IV disease were more likely to experience disease progression (P = .005). Additionally, higher histological grade (as determined by Ki-67 index >2%) was associated with a decreased PFS (P = .001). Ki-67 index greater than 2% at either the primary site or the metastatic site was found to be the only significant predictor of PFS after consideration of all other variables in an adjusted analysis. In conclusion, the Ki-67 index predicts PFS of patients with ileal wNETs.

Primary vascular tumors and tumor-like lesions of the kidney: a clinicopathologic analysis of 25 cases.

Vascular tumors of the kidney are distinctly rare, and to date no large series have been reported. We analyzed a series of primary vascular tumors of the kidney to further delineate their clinicopathologic features and identify organ-specific morphologic features, if present. Twenty-five renal cases previously coded as "arteriovenous malformation," "hemangioma," and "angiosarcoma" were retrieved from the archives of 4 collaborating institutions and were reevaluated histologically. Tumors were classified according to the 2002 World Health Organization classification of tumors of soft tissue and bone. There were 18 males and 7 females (M:F=2.6:1) ranging from 21 to 95 years (mean 56.7 y). Lesions ranged from "microscopic" to 30 cm (mean 6.0 cm) and were tan-brown, cystic, and hemorrhagic. On re-review, cases were classified as arteriovenous malformation (n=3), capillary hemangioma (n=14), and angiosarcoma (n=8). Arteriovenous malformations were identical to their somatic soft tissue counterparts. Renal capillary hemangiomas often lacked a well-formed lobular pattern and 5 cases showed a "sieve-like" arrangement reminiscent of splenic sinusoids, a pattern previously noted by others (anastomosing hemangioma). All hemangiomas were noninfiltrative and lacked cytologic atypia and mitotic activity. GLUT-1, D2-40, and CD8 were performed in 3 anastomosing hemangiomas and were all negative. Angiosarcomas were diffusely infiltrative with extensive parenchymal destruction; all showed at least small areas of conventional vasoformative growth, but were frequently dominated by spindled and epithelioid histology. All cases were positive for some combination of vascular tumor-associated markers (CD31, CD34, and FLI-1). Cytokeratin expression was absent in all angiosarcomas. Follow-up was available for 15 cases: all patients with arteriovenous malformation and hemangioma with follow-up were disease free after complete excision; 4 cases of angiosarcoma died of the disease at 1, 1, 6, and 11 months. Our review shows that many capillary hemangiomas of the kidney are morphologically distinctive tumors, which often show "spleen-like" or "anastomosing" features. Angiosarcomas of the kidney are highly aggressive tumors with poor outcome and may have morphologic features (spindling and epithelioid change), which could result in confusion with sarcomatoid carcinomas and other renal mesenchymal tumors.

Dedifferentiated liposarcoma of the retro-peritoneum: histologically low-grade type.

A dedifferentiated liposarcoma of the retro-peritoneum of a 45-year-old female is described in this case report. It showed dedifferentiation into a histological low-grade type and thus defies the traditional definition of dedifferentiated liposarcoma. The excised specimen was a huge, multi-nodular encapsulated mass surrounding the kidney and infiltrating into it. The mass showed a dedifferentiated focus different in color from the surrounding tumor and containing areas of necrosis and hemorrhage. The sections from the dedifferentiated part of the tumor appeared predominantly as benign spindle cell component on histology but the tumor was infiltrating into the kidney. Hence, a close and long-term follow-up is expected in such cases though they look benign. In the retro-peritoneum, a lipoma-like well-differentiated liposarcoma with spindle cell component, like the present tumor, which shows dedifferentiation, should not be overlooked.