Occult primary, version 3.2014

The NCCN Guidelines for Occult Primary tumors provide recommendations for the evaluation, workup, management, and follow-up of patients with occult primary tumors (cancers of unknown primary). These NCCN Guidelines Insights summarize major discussion points of the 2014 NCCN Occult Primary panel meeting. The panel discussed gene expression profiling (GEP) for the identification of the tissue of origin and concluded that, although GEP has a diagnostic benefit, a clinical benefit has not been demonstrated. The panel recommends against GEP as standard management, although 20% of the panel believes the diagnostic benefit of GEP warrants its routine use. In addition, the panel discussed testing for actionable mutations (eg, ALK) to help guide choice of therapy, but declined to add this recommendation.

MicroRNA-21 promotes glioblastoma tumorigenesis by down-regulating insulin-like growth factor-binding protein-3 (IGFBP3)

Despite advances in surgery, imaging, chemotherapy, and radiation, patients with glioblastoma multiforme (GBM), the most common histological subtype of glioma, have an especially dismal prognosis; >70% of GBM patients die within 2 years of diagnosis. In many human cancers, the microRNA miR-21 is overexpressed, and accumulating evidence indicates that it functions as an oncogene. Here, we report that miR-21 is overexpressed in human GBM cell lines and tumor tissue. Moreover, miR-21 expression in GBM patient samples is inversely correlated with patient survival. Knockdown of miR-21 in GBM cells inhibited cell proliferation in vitro and markedly inhibited tumor formation in vivo. A number of known miR-21 targets have been identified previously. By microarray analysis, we identified and validated insulin-like growth factor (IGF)-binding protein-3 (IGFBP3) as a novel miR-21 target gene. Overexpression of IGFBP3 in glioma cells inhibited cell proliferation in vitro and inhibited tumor formation of glioma xenografts in vivo. The critical role that IGFBP3 plays in miR-21-mediated actions was demonstrated by a rescue experiment, in which IGFBP3 knockdown in miR-21KD glioblastoma cells restored tumorigenesis. Examination of tumors from GBM patients showed that there was an inverse relationship between IGFBP3 and miR-21 expression and that increased IGFBP3 expression correlated with better patient survival. Our results identify IGFBP3 as a novel miR-21 target gene in glioblastoma and suggest that the oncogenic miRNA miR-21 down-regulates the expression of IGFBP3, which acts as a tumor suppressor in human glioblastoma.

Comparison of histopathology to gene expression profiling for the diagnosis of metastatic cancer

Background

Determining the primary site of metastatic cancer with confidence can be challenging. Pathologists commonly use a battery of immunohistochemical (IHC) stains to determine the primary site. Gene expression profiling (GEP) has found increasing use, particularly in the most difficult cases. In this pilot study, a direct comparison between GEP and IHC-guided methods was performed.

Methods

Ten archived formalin-fixed paraffin embedded metastatic tumor samples for which the primary site had been clinically determined were selected. Five pathologists who were blinded to the diagnosis were asked to determine the primary site using IHC and other stains selected from a panel of 84 stains. Each pathologist was provided patient sex, biopsy site and gross sample description only. Slides were digitized using ScanScope®XT at 0.25 μm/pixel. Each evaluating pathologist was allowed to provide a diagnosis in three stages: initial (after reviewing the H&E image), intermediate (after reviewing images from the first batch of stains) and final diagnosis (after the second batch of stains if requested). GEP was performed using the only FDA-cleared test for this intended use, the Pathwork Tissue of Origin Test. No sample information was provided for GEP testing except for patient sex. Results were reported as the tumor tissue type with the highest similarity score.

Results

In this feasibility study, GEP determined the correct primary site in 9 of the 10 cases (90%), compared to the IHC-guided method which determined the correct primary site for 32 of 50 case evaluations (average 64%, range 50% to 80%). The five pathologists directing the IHC-guided method ordered an average of 8.8 stains per case (range 1 to 18). GEP required an average of 3 slides per case (range 1 to 4).

Conclusions

Results of the pilot study suggest that GEP provides correct primary site identification in a higher percentage of metastatic cases than IHC-guided methods, and uses less tissue. A larger comparative effectiveness study using this study design is needed to confirm the results.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1749854104745508

Gene expression analysis and immunohistochemistry in evaluation of cancer of unknown primary: time for a patient-centered approach

Molecular medicine is rapidly changing the diagnosis and management of cancer of unknown primary. The science, business, and economics of the genomic revolution have moved at such a pace that coordinating practical application of all available tools, such as gene expression analysis and immunohistochemistry, often seems to clash. In fact, very little work has been done to actively coordinate use of these techniques, each of which can be very resource-intensive. The Institute of Medicine proposed the STEEEP principles, a basic set of guidelines that maintain that the best patient care is safe, timely, effective, efficient, equitable, and patient-centered. Application of these principles will help lead to a better understanding of the most appropriate use of modern diagnostic modalities.

NCCN Clinical Practice Guidelines Occult primary

Occult primary tumors, or cancers of unknown primary (CUPs), are defined as histologically proven metastatic malignant tumors whose primary site cannot be identified during pretreatment evaluation. They have a wide variety of clinical presentations and a poor prognosis in most patients. Patients with occult primary tumors often present with general complaints, such as anorexia and weight loss. Clinical absence of primary tumor, early dissemination, aggressiveness, and unpredictability of metastatic pattern are characteristic of these tumors. Life expectancy is very short, with a median survival of 6 to 9 months. In most patients, occult primary tumors are refractory to systemic treatments, and chemotherapy is only palliative and does not significantly improve long-term survival. However, certain clinical presentations of these tumors are associated with a better prognosis. Special pathologic studies can identify subsets of patients with tumor types that are more responsive to chemotherapy. Treatment options should be individualized for this selected group of patients to achieve improved response and survival rates.

Oral cancer: enduring characteristics and emerging trends

Oral cancer is arguably the most serious condition that dental providers may encounter in their practice. The relatively poor prognosis associated with oral cancer highlights the importance of the dental team's awareness of the disease. While many characteristics of oral cancer have endured over time, new research is revealing trends that are changing the way we approach its screening, diagnosis and treatment. In this report, we provide a translational overview of oral cancer, including risk factors, signs and symptoms, clinical management, as well as our recent findings on the role of chronic inflammation in the development of the disease. In addition, our recent genetic profiling approach in both cancer cell lines and in patients has identified potential biomarkers, molecular pathways and therapeutic drugs for oral squamous cell carcinomas. This comprehensive review should be of interest to all dental professionals.

MicroRNA miR-21 regulates the metastatic behavior of B16 melanoma cells

MicroRNA-21 (miR-21) is overexpressed in many human tumors and has been linked to various cellular processes altered in cancer. miR-21 is also up-regulated by a number of inflammatory agents, including IFN, which is of particular interest considering the close relationship between inflammation and cancer. Because miR-21 appears to be overexpressed in human melanoma, we examined the role of miR-21 in cancer development and metastasis in B16 mouse melanoma cells. We found that miR-21 is a member of an IFN-induced miRNA subset that requires STAT3 activation. To characterize the role of miR-21 in melanoma behavior, we transduced B16 cells with lentivirus encoding a miR-21 antagomir and isolated miR-21 knockdown B16 cells. miR-21 knockdown or IFN treatment alone inhibited B16 cell proliferation and migration in vitro, and in combination they had an enhanced effect. Moreover, miR-21 knockdown sensitized B16 cells to IFN-induced apoptosis. In B16 cells miR-21 targeted tumor suppressor (PTEN and PDCD4) and antiproliferative (BTG2) proteins. To characterize the role of miR-21 in vivo, empty vector- and antagomiR-21-transduced B16 melanoma cells were injected via tail vein into syngeneic C57BL/6 mice. Although empty vector-transduced B16 cells produced large lung metastases, miR-21 knockdown cells only formed small lung lesions. Importantly, miR-21 knockdown tumor-bearing mice exhibited prolonged survival compared with empty vector tumor-bearing mice. Thus, miR-21 regulates the metastatic behavior of B16 melanoma cells by promoting cell proliferation, survival, and migration/invasion as well as by suppressing IFN action, providing important new insights into the role of miR-21 in melanoma.

Oral cancer: enduring characteristics and emerging trends

Oral cancer is arguably the most serious condition that dental providers may encounter in their practice. The relatively poor prognosis associated with oral cancer highlights the importance of the dental team's awareness of the disease. While many characteristics of oral cancer have endured over time, new research is revealing trends that are changing the way we approach its screening, diagnosis and treatment. In this report, we provide a translational overview of oral cancer, including risk factors, signs and symptoms, clinical management, as well as our recent findings on the role of chronic inflammation in the development of the disease. In addition, our recent genetic profiling approach in both cancer cell lines and in patients has identified potential biomarkers, molecular pathways and therapeutic drugs (Velcade and Aspirin) for oral squamous cell carcinomas. This comprehensive review should be of interest to all dental professionals.

VHL deletion impairs mammary alveologenesis but is not sufficient for mammary tumorigenesis

Overexpression of hypoxia inducible factor-1 (HIF-1)alpha, which is common in most solid tumors, correlates with poor prognosis and high metastatic risk in breast cancer patients. Because HIF-1alpha protein stability is tightly controlled by the tumor suppressor von Hippel-Lindau (VHL), deletion of VHL results in constitutive HIF-1alpha expression. To determine whether VHL plays a role in normal mammary gland development, and if HIF-1alpha overexpression is sufficient to initiate breast cancer, Vhl was conditionally deleted in the mammary epithelium using the Cre/loxP system. During first pregnancy, loss of Vhl resulted in decreased mammary epithelial cell proliferation and impaired alveolar differentiation; despite these phenotypes, lactation was sufficient to support pup growth. In contrast, in multiparous dams, Vhl(-/-) mammary glands exhibited a progressive loss of alveolar epithelium, culminating in lactation failure. Deletion of Vhl in the epithelium also impacted the mammary stroma, as there was increased microvessel density accompanied by hemorrhage and increased immune cell infiltration. However, deletion of Vhl was not sufficient to induce mammary tumorigenesis in dams bred continuously for up to 24 months of age. Moreover, co-deletion of Hif1a could not rescue the Vhl(-/-)-dependent phenotype as dams were unable to successfully lactate during the first lactation. These results suggest that additional VHL-regulated genes besides HIF1A function to maintain the proliferative and regenerative potential of the breast epithelium.

The Effect of Bacterial Contamination on Neointimal Hyperplasia in Vascular Grafts

Neointimal hyperplasia (NH) is the most significant contributing factor to long-term vascular graft failure. Inflammation is known to be important in its development; however, the role of bacterial infection is unclear. We examined the effect of contamination with common organisms on the development of NH in expanded polytetrafluoroethylene grafts. Thirty adult pigs were randomized into one of four groups: no infection, contamination with Staphylococcus aureus, mucin-producing Staphylococcus epidermidis, or Pseudomonas aeruginosa. An expanded polytetrafluoroethylene graft (6 mm x 3 cm) was placed as a common iliac artery interposition graft and was inoculated with 1–2 x 108 of the selected organism before closure. Grafts were explanted 6 weeks postoperatively. Microbiologic, histological, and morphometric evaluations were performed. All grafts were patent at the time of euthanasia. The mean areas of NH were 5.45 mm2 in sterile grafts, 8.36 mm2 in S. aureus, 7.63 mm2 in S. epidermidis, and 11.52 mm2 in P. aeruginosa grafts. Comparison of means via analysis of variance showed that P. aeruginosa grafts had significantly higher formation of NH than sterile grafts (P = 0.025). NH production in infected grafts appears to be organism specific and is significantly higher with P. aeruginosa than common Gram-positive organisms. Increased NH from subclinical infection may be a significant factor contributing to late graft failures.

The effect of bacterial contamination on neointimal hyperplasia in vascular grafts

Neointimal hyperplasia (NH) is the most significant contributing factor to long-term vascular graft failure. Inflammation is known to be important in its development; however, the role of bacterial infection is unclear. We examined the effect of contamination with common organisms on the development of NH in expanded polytetrafluoroethylene grafts. Thirty adult pigs were randomized into one of four groups: no infection, contamination with Staphylococcus aureus, mucin-producing Staphylococcus epidermidis, or Pseudomonas aeruginosa. An expanded polytetrafluoroethylene graft (6 mm x 3 cm) was placed as a common iliac artery interposition graft and was inoculated with 1-2 x 10(8) of the selected organism before closure. Grafts were explanted 6 weeks postoperatively. Microbiologic, histological, and morphometric evaluations were performed. All grafts were patent at the time of euthanasia. The mean areas of NH were 5.45 mm(2) in sterile grafts, 8.36 mm(2) in S. aureus, 7.63 mm(2) in S. epidermidis, and 11.52 mm(2) in P. aeruginosa grafts. Comparison of means via analysis of variance showed that P. aeruginosa grafts had significantly higher formation of NH than sterile grafts (P = 0.025). NH production in infected grafts appears to be organism specific and is significantly higher with P. aeruginosa than common Gram-positive organisms. Increased NH from subclinical infection may be a significant factor contributing to late graft failures.

Skin basement membrane zone: a depository for circulating microbial antigen evoking psoriasis and autoimmunity

BACKGROUND

Elevated levels of antibody to streptococcal exoenzymes have been found in patients with psoriasis or psoriatic arthritis. Research on the role of streptococcal antigen in psoriasis has been hampered by a potential molecular mimicry between streptococcal epitopes and human epidermal keratin.

OBJECTIVE AND METHODS

Evidence of microbial product was sought in skin biopsies of psoriasis patients thought clinically to have either streptococcal carrier state or gastrointestinal candidal colonization. A polyclonal antibody to streptococcal-derived exoenzymes unlikely to share antigenic structures with normal human skin, and an anticandidal antibody, were used with linked streptavidin biotin amplification stain.

RESULTS

The predicted microbial product appeared heavily in lesional epidermis, but unexpectedly also as a thin deposit along the skin basement membrane zone (SBMZ) of apparently unaffected skin. Staining was negative for nonpsoriatic subjects.

CONCLUSIONS

The findings support a direct effect of microbial antigen in psoriasis. They also suggest an important role for SBMZ as a very large adhesive surface in the first step of a process of percutaneous epidermal elimination of foreign antigens and microbial toxins. The many autoimmune phenomena seen so often at the SBMZ are probably a physiologic part of this important immune function. Efforts to enhance the adhesive properties of SBMZ should be exploitable for both diagnostic and therapeutic benefit.

Rapamycin-coated expanded polytetrafluoroethylene bypass grafts exhibit decreased anastomotic neointimal hyperplasia in a porcine model

OBJECTIVE

We tested the hypothesis that rapamycin coated onto, and eluted from, expanded polytetrafluoroethylene (ePTFE) grafts would diminish neointimal hyperplasia in a porcine model.

METHODS

Rapamycin (also called sirolimus) was coated onto the luminal surface of 6-mm-internal-diameter thin-walled ePTFE grafts by using an adhesive polymer that allows timed release of the drug. An adhesive polymer that allows timed release of rapamycin from ePTFE was developed with commercially available chemicals and applied on 6-mm ePTFE grafts. Graft integrity was characterized by scanning electron microscopy, and rapamycin levels were quantified by using high-performance liquid chromatography. Twenty-two mongrel pigs were randomized into three groups: untreated ePTFE (n = 6), adhesive-only coated ePTFE (n = 6), or adhesive- and rapamycin-coated ePTFE (n = 10). End-to-side unilateral aortoiliac bypasses were performed by using 6-mm-internal-diameter ePTFE grafts and standardized anastomotic lengths. Unilateral end-to-side aortoiliac ePTFE grafts (6-mm internal diameter) were inserted by using polypropylene sutures, 6-0 proximally and 7-0 distally; all anastomoses were 12 mm long. All animals received aspirin (325 mg orally) daily. All animals were given oral aspirin (325 mg) daily beginning on the day before surgery. At 28 days, the animals were killed, and the grafts were explanted in continuity with the adjacent aortic cuff and the outflow iliac artery. Variables compared between groups included graft patency, distal anastomotic length and cross-sectional narrowing, and intimal thickness at the arterial-graft junction indexed to the adjacent graft thickness. Microscopic analysis was performed with hematoxylin and eosin and Masson trichrome stains on paraffin sections. A pathologist blinded to experimental groups graded sections for collagen deposition, neointima formation, inflammatory cellular infiltrates, medial necrosis, and aneurysmal degeneration.

RESULTS

All animals survived until they were killed without clinical evidence of limb ischemia or graft infection. Preplanned t tests in the context of one-way analysis of variance showed no difference in outcome measures between the untreated ePTFE and adhesive-only coated ePTFE groups; therefore, they were combined in further comparisons with the adhesive- and rapamycin-coated ePTFE group. The Rapamycine eluting expanded polytetrafluoroethylene group had longer anastomoses (85.6% vs 60.6% of the initial anastomotic length maintained; P < .0001) and less cross-sectional narrowing in the outflow graft (16.2% vs 28.5%; P = .0007) when compared with the other two groups by using two-tailed Student t tests. There was no evidence of medial necrosis or aneurysmal degeneration. All patent grafts had complete endothelialization on hematoxylin and eosin sections. Rapamycin was detectable and quantifiable in the arterial wall at 28 days after implantation.

CONCLUSIONS

Rapamycin can be coated onto and eluted from ePTFE by using a nonionic polymer and a simple coating technique. At 4 weeks after implantation, the rapamycin-eluting ePTFE grafts demonstrate gross, pathologic, and morphometric features of diminished neointimal hyperplasia when compared with non-drug-eluting ePTFE. Four weeks after implantation in a porcine model, rapamycin-eluting ePTFE grafts demonstrated gross, pathologic, and morphometric features of diminished neointimal hyperplasia when compared with untreated and adhesive-only coated ePTFE grafts.

CLINICAL RELEVANCE

Rapamycin-eluting ePTFE grafts decrease neointimal hyperplasia in a porcine model. Further studies are needed to evaluate whether patency will be improved. Rapamycin-eluting ePTFE grafts may allow the use of prosthetic grafts in situations in which autologous vein is unavailable and in which neointimal hyperplasia is pronounced, such as in small-diameter (<6-mm) vessels typical of infrapopliteal interventions.

Small intestinal submucosa for vascular reconstruction in the presence of gastrointestinal contamination

INTRODUCTION

Surgical options for vascular reconstruction in a contaminated field are limited and include prosthetic reconstruction or ligation with extra-anatomic bypass. With prosthetic insertion, rates of graft infection and failures (pseudoaneurysms and thrombosis) are high. In the emergent situations, extra-anatomic bypass is time-consuming and complex, and it produces marginal long-term results. Small intestinal submucosa (SIS) is a cell-free collagen matrix derived from porcine small intestine. Preliminary studies have demonstrated its ability to be remodeled into host tissue. In this study, we compared SIS to polytetrafluoroethylene (PTFE) as a vascular patch for arterial repair in the presence of massive gastrointestinal contamination to evaluate graft patency, incorporation, infection, and aneurysm formation.

METHODS

Adult mongrel pigs underwent general anesthesia with Isoflurane and were then randomized to 1 of 3 groups: control, contamination (colon puncture with stool contamination of the pelvis), or shock + contamination (40% blood volume for 1 hour, then resuscitation with shed blood and crystalloid, plus contamination). All groups then underwent a left common iliac arteriotomy and further randomized to a 1 x 3-cm patch angioplasty with either SIS or PTFE. All received cefotetan for 24 hours. All animals were sacrificed between 2 and 4 weeks, and necropsy was performed. Grafts were cultured, and microscopic analysis with hematoxylin and eosin and trichrome was performed. Outcomes included pulse quality (normal or diminished) compared with opposite side, graft infection, and pseudoaneurysm; all were determined by a blinded investigator.

RESULTS

Forty animals were randomized, and 1 died of abdominal sepsis. All control animals had normal distal pulses, no pseudoaneurysms, and no patch infections. The pseudoaneurysm rate for the contaminated PTFE patches was 25% compared with 0% in the SIS group (P = 0.09). Patch infection occurred in 73% of all PTFE patches compared with 8% of SIS patches (P < 0.03). Organisms present in the infected grafts included Escherichia coli, Bacteroides species, and other Gram-negative enterics. Histopathology demonstrated the presence of neointima in both SIS and PTFE. Only SIS was completely incorporated, with infiltration of collagen fibrils and lymphocytes.

CONCLUSIONS

SIS was associated with improved graft patency, less infection, complete incorporation, and no false aneurysm formation when compared with PTFE. This may be due to its ability to provide a durable scaffold for cellularization and tissue remodeling. This material may offer a superior alternative to more complex vascular reconstruction techniques in contaminated fields.

Carbamoylation of glomerular and tubular proteins in patients with kidney failure: a potential mechanism of ongoing renal damage

BACKGROUND

Cyanate formed spontaneously from urea carbamoylates non-protonated amino groups of protein, irreversibly altering function, charge and structure. Carbamoylated proteins in renal tissue have not been examined hitherto.

OBJECTIVES

To identify homocitrulline (epsilon-amino-carbamoyl-lysine), a result of in vivo carbamoylation by urea-derived cyanate, from patients with renal disease or in newly transplanted kidneys by immunohistochemistry. To evaluate enzymatic activity of carbamoylated and non-carbamoylated matrix metalloproteinase-2 and correlate this with renal tissue carbamoylated in vivo.

DESIGN

Anti-homocitrulline antibody is specific for homocitrulline and was used to identify carbamoylation of epsilon-amino-lysine in renal biopsies from patients with elevated BUN, with isolated proteinuria, and as controls, from normal donors at time of transplantation. Enzymatic activity of matrix metalloproteinase-2 carbamoylated in vitro was evaluated.

RESULTS

Homocitrulline was present in glomerular basement membrane (8/10), mesangium (8/10), tubular epithelium and cytoplasm (7/10) and Bowman's capsule (1/10) in patients with elevated BUN. The discordant patterns of glomerular and tubular localization of homocitrulline versus immune complexes indicated that the carbamoylated proteins were not a component of immune deposits but were modified proteins in renal tissue. No homocitrulline was found in transplanted kidneys (14/15) or in proteinuric patients (2/2). Enzymatic activity of both human and rat matrix metalloproteinase-2 was strongly inhibited in a dose-dependent fashion when incubated with cyanate.

CONCLUSIONS

In situ carbamoylation in proteins occurred in kidneys of patients with renal dysfunction but not in normal newly transplanted kidneys. Decreased enzymatic activity of carbamoylated enzymes may alter specific renal regulatory mechanisms. Carbamoylated proteins with altered function and charge may represent a previously underestimated mechanism in renal pathophysiology.

Carbamoylation of glomerular and tubular proteins in patients with kidney failure: a potential mechanism of ongoing renal damage

BACKGROUND

Cyanate formed spontaneously from urea carbamoylates non-protonated amino groups of protein, irreversibly altering function, charge and structure. Carbamoylated proteins in renal tissue have not been examined hitherto.

OBJECTIVES

To identify homocitrulline (epsilon-amino-carbamoyl-lysine), a result of in vivo carbamoylation by urea-derived cyanate, from patients with renal disease or in newly transplanted kidneys by immunohistochemistry. To evaluate enzymatic activity of carbamoylated and non-carbamoylated matrix metalloproteinase-2 and correlate this with renal tissue carbamoylated in vivo.

DESIGN

Anti-homocitrulline antibody is specific for homocitrulline and was used to identify carbamoylation of epsilon-amino-lysine in renal biopsies from patients with elevated BUN, with isolated proteinuria, and as controls, from normal donors at time of transplantation. Enzymatic activity of matrix metalloproteinase-2 carbamoylated in vitro was evaluated.

RESULTS

Homocitrulline was present in glomerular basement membrane (8/10), mesangium (8/10), tubular epithelium and cytoplasm (7/10) and Bowman's capsule (1/10) in patients with elevated BUN. The discordant patterns of glomerular and tubular localization of homocitrulline versus immune complexes indicated that the carbamoylated proteins were not a component of immune deposits but were modified proteins in renal tissue. No homocitrulline was found in transplanted kidneys (14/15) or in proteinuric patients (2/2). Enzymatic activity of both human and rat matrix metalloproteinase-2 was strongly inhibited in a dose-dependent fashion when incubated with cyanate.

CONCLUSIONS

In situ carbamoylation in proteins occurred in kidneys of patients with renal dysfunction but not in normal newly transplanted kidneys. Decreased enzymatic activity of carbamoylated enzymes may alter specific renal regulatory mechanisms. Carbamoylated proteins with altered function and charge may represent a previously underestimated mechanism in renal pathophysiology.

Assuring quality in laboratory testing at the point of care

The science of laboratory medicine has undergone much change during recent years. Despite more recent emphasis on quality improvement, there has not been sufficient attention paid to effective quality management of new approaches to laboratory testing such as point of care testing. It is important that appropriate resources be allocated to quality management, so that waste is minimized and that resources which are expended may be demonstrated to affect the quality of patient care in a positive way. Older quality management tools such as process quality control and proficiency testing are vital to the success of point of care testing programs, however, new ways of looking at the use of these tools are required. Newer approaches such as electronic quality control of point of care devices and an expanded role of total quality management strategies will enhance rather than supplant the more traditional quality improvement mechanisms.

Solitary spinal cord sarcoidosis without other manifestations of systemic sarcoidosis

We report a biopsy-proven case of sarcoidosis limited to the spinal cord and responsive to treatment with oral corticosteroids. Involvement of the spinal cord by systemic sarcoidosis is uncommon and is associated with several unusual pathological and radiological characteristics that may contribute to its misdiagnosis and subsequent mismanagement. The importance of these unusual characteristics is greatly amplified in solitary spinal cord sarcoidosis because there are no systemic findings to suggest a sarcoid etiology.

Further observations on the etiology of pre-eclampsia: mobilization of toxic cadmium-metallothionein into the serum during pregnancy

Cadmium-metallothionein, mobilized from the liver, might be the toxic serum factor associated with pre-eclampsia. We base this on four documented concepts. First, during pregnancy, maternal physiology adjusts to assure the fetus of the proper amounts of nutrients necessary for growth. Our focus is on zinc and progesterone. Second, because zinc and cadmium are similar, they compete for binding sites. Our focus is on the storage protein metallothionein. Third, the manifestations of cadmium toxicity closely mimic the manifestations of toxemia (i.e. hypertension, proteinuria, edema). Our focus is on cadmium-induced endovasculitis. Fourth is the concept that metallothionein-bound cadmium can be mobilized from the liver into the serum during pregnancy as it follows the mobilization of metallothionein-bound zinc. Our focus is on the extreme toxicity of extracellular cadmium-metallothionein. We correlate these four concepts into a rational theory on the etiology of toxemia, and we suggest a method of proof.

Solitary focal demyelination in the brain as a paraneoplastic disorder

Solitary focal demyelination (SFD) in the brain is an uncommon and poorly understood disorder of uncertain etiology that may represent an intermediate entity between multiple sclerosis and acute disseminated encephalomyelitis. In a few reported cases of SFD, the patient was briefly noted to have a nonneurological malignancy. We studied two patients who had solitary focal lesions in the brain. Utilizing magnetic resonance imaging and tissue biopsy, we found the characteristics of the brain lesions in these two patients to be those of SFD. In our combined experience over the past 10 years, we have encountered no similar brain lesions at our medical center. We found it remarkable that both of these patients also had malignancy outside of the nervous system. One had a seminoma, and the other a lymphoma. We conclude that some cases of SFD in the brain may occur as a paraneoplastic disorder associated with nonneurological malignancies.

The mobile laboratory in alternative site testing

The establishment of mobile or portable laboratories as one strategy for delivery of laboratory services at alternative sites is evaluated. The mobile laboratory may be used to replace centralized laboratory testing in areas of critical need, such as critical care areas of the hospital in which relatively large numbers of tests are needed quickly. Other possible areas of use include outpatient clinics and other outreach settings in which care of the patient may be hastened by the availability of laboratory data on a real-time basis. In such areas where a need is established, mobile laboratory testing may be performed economically and may enhance the position of the medical technologist as a hands-on clinical caregiver.

College of American Pathologists Conference XXVIII on alternate site testing: introduction

The College of American Pathologists Conference XXVIII, Alternate Site Testing Conference: Venturing Beyond the Boundaries of the Clinical Laboratory, was held from January 29 through February 1, 1995. This open format consensus conference gathered together individuals with many different points of view on the topic of hospital laboratory testing in noncentralized laboratories. The goals of the conference were to establish a basis for common beliefs about alternate site testing, to discover where consensus existed, and to establish future directions for consensus development and resolution of disputes in this sometimes contentious and confusing area of laboratory medicine. Attainment of the goals was attempted through a variety of conference activities, including plenary addresses, poster sessions, and, most importantly, through open-forum breakout sessions. During the breakout sessions all conference attendees were invited to contribute ideas toward the development of consensus about critical issues surrounding alternate site testing. Although it is clear that much work remains to be done if we are to learn how to use alternate site testing strategies to the best advantage, an important beginning has been made. The stage has been set as we continue to provide high-quality laboratory testing in an era that demands both fast turnaround time and optimal cost effectiveness.

Background--setting the stage for alternate-site laboratory testing

Market forces and service demands are driving a segment of laboratory testing away from centralized laboratories and closer to the patient's bedside. Placed into a historical perspective, this should be neither surprising nor distressing. Terminology is being clarified and professional societies are beginning to take the lead in molding these testing strategies into appropriate tools for advancing excellent patient care.

Quality control and quality management of alternate-site testing

Quality is an important attribute of clinical laboratory results; however, methods for defining acceptable quality may not be entirely agreed upon. In addition, confusion over quality is added when laboratory testing is moved to alternate sites. As quality parameters are designed for novel laboratory delivery systems, it will be best to use novel approaches that build on already well-defined principles of laboratory quality management.

Urea-derived cyanate forms epsilon-amino-carbamoyl-lysine (homocitrulline) in leukocyte proteins in patients with end-stage renal disease on peritoneal dialysis

Carbamoylated proteins have been located by using a site-specific polyclonal antihomocitrulline antibody and a fluorescent secondary antibody in leukocytes from patients with end-stage renal disease who were undergoing maintenance continuous ambulatory peritoneal dialysis. A covalent reaction with urea-derived cyanate and the epsilon-amino group of lysine forms homocitrulline residues in carbamoylated proteins. Isocyanic acid, the reactive form of cyanate, is spontaneously formed from urea in aqueous solution at physiologic pH and temperature. In washed, fixed monolayers of cells, an intracellular fluorescent antigen-antibody complex was located throughout the cytoplasm of polymorphonuclear neutrophils (PMNs) and monocytes from 11 patients with blood urea nitrogen (BUN) levels ranging from 32 to 102 mg/dl who were undergoing dialysis for 2 to 135 months. A punctate fluorescence present in the cell surface proteins of living cells demonstrated that lysine residues in the external domain of proteins were carbamoylated, forming homocitrulline. In contrast, we found a perinuclear fluorescence in PMNs in normal subjects with no history of renal insufficiency and BUN levels of 6 to 19 mg/dl. This suggests that homocitrulline is located in carbamoylated proteins within the perinuclear membrane, a structural organelle continuous with the endoplasmic reticulum. It appears that continuous exposure to urea-derived cyanate in low levels results in increasing carbamoylation of stable proteins over the PMN's lifetime. When normal PMNs were exposed to 120 mmol/L cyanate ion in vitro for 10 to 30 minutes, the ability of PMNs to release microbicidal superoxide was strongly inhibited. Thus protein carbamoylation may provide a regulatory mechanism. The altered function of PMNs in renal disease may be due in part to the posttranslational modification of proteins by urea-derived cyanate.

Increased absorption of and sensitivity to cadmium during late pregnancy: is there a relationship between markedly decreased maternal cadmium binding protein (metallothionein) and pregnancy-induced hypertension?

Laboratory animals have a unique sensitivity to cadmium toxicity in late pregnancy. This acute toxicity is not seen in non-pregnant, early pregnant, or lactating animals. Furthermore, during late pregnancy, laboratory animals absorb and retain substantially more cadmium from their diets than they do in the non-pregnant state. Both of these observations parallel the fact that a fivefold late gestational drop of maternal metallothionein (a metal-binding protein believed to detoxify cadmium) has been demonstrated in pregnant animals. Additional factors such as nutritional status and age affect cadmium absorption. As we have discussed previously, cadmium toxicity and toxemia of pregnancy have many common features including hypertension, proteinuria, edema, vasospasm and endovasculitis. Because of the above, we propose that cadmium plays a role in the etiology of toxemia.

Zinc, cadmium, metallothionein, and progesterone: do they participate in the etiology of pregnancy induced hypertension?

Cadmium, a toxic heavy metal, has been incriminated in the etiology of essential hypertension. Zinc, an essential micronutrient necessary for growth, competes with cadmium for binding sites in biochemical processes; zinc deficiency states (i.e. pregnancy and low protein diet) might expose an individual to increased risk of cadmium toxicity. The increased sensitivity to cadmium during pregnancy could also be related to the effect of progesterone on zinc and cadmium metabolism through the actions of metallothionein (MT). MT is a low molecular weight protein believed to function in cadmium detoxification. Several studies in lab animals have documented a late gestation drop of maternal MT levels. This was thought to be due to rising progesterone levels. If there is also a late gestation drop in human maternal MT, then the propensity toward maternal cadmium toxicity would be enhanced. Therefore, we propose that when a zinc deficient woman becomes pregnant and is exposed to both the nutritional demands of the fetus and to the influence of progesterone, she will be likely to develop the manifestations of cadmium toxicity (i.e. hypertension, proteinuria, edema, etc.).

Elevated serum bromide in patients taking lithium carbonate

Serum bromide levels were determined for 20 patients receiving lithium carbonate for manic depressive illness. Bromides averaged 17.06 +/- 8.15 mg/dl, which exceeded the control average of 3.22 +/- 3.2 mg/dl. Elevated serum bromide in patients taking lithium may reflect altered renal function.

Fatal subscapular staphylococcal abscess

A previously healthy 19-year-old man had a Staphylococcus aureus subscapular abscess after trauma to the shoulder, leading to sepsis, pneumonia, and death. Subscapular abscesses are infrequently described and might represent diagnostic difficulty to the clinician as well as to the unwary autopsy pathologist.

Intrathoracic lipomas in children

An asymptomatic 8-year-old boy had had a large intrathoracic tumor for five years. When noninvasive technics proved fruitless in establishing a diagnosis, surgical removal was elected. A large posterior mediastinal lipoma was discovered. This is the 15th intrathoracic lipoma reported in the pediatric age group.