Intraoperative Assessment of the Resection Specimen Facilitates Achievement of Adequate Margins in Oral Carcinoma

Background

Inadequate resection margins in oral cavity squamous cell carcinoma have an adverse effect on patient outcome. Intraoperative assessment provides immediate feedback enabling the surgeon to achieve adequate resection margins. The goal of this study was to evaluate the value of specimen-driven intraoperative assessment by comparing the margin status in the period before and the period after the introduction of specimen-driven assessment as a standard of care (period 2010-2012 vs period 2013-2017).

Methods

A cohort of patients surgically treated for oral squamous cell carcinoma at the Erasmus MC Cancer Institute, Rotterdam, between 2010-2012 was studied retrospectively and compared to results of a prospectively collected cohort between 2013-2017. The frequency, type and results of intraoperative assessment of resection margins were analyzed.

Results

One hundred seventy-four patients were included from 2010-2012, 241 patients were included from 2013-2017. An increase in the frequency of specimen-driven assessment was seen between the two periods, from 5% in 2010-2012 to 34% in 2013-2017. When performing specimen-driven assessment, 16% tumor-positive resection margins were found in 2013-2017, compared to 43% tumor-positive resection margins overall in 2010-2012. We found a significant reduction of inadequate resection margins for specimen-driven intraoperative assessment (p < 0.001). Also, tumor recurrence significantly decreased, and disease-specific survival improved when performing specimen-driven intraoperative assessment.

Conclusions

Specimen-driven intraoperative assessment improves resection margins and consequently, the outcome of oral cancer patients. We advocate this method as standard of care.

Precursor lesions of vulvar squamous cell carcinoma - histology and biomarkers: A systematic review

The precursor lesion of vulvar squamous cell carcinoma (VSCC), namely vulvar intraepithelial neoplasia (VIN), is classified as: human papillomavirus (HPV)-related high grade squamous intraepithelial lesion (HSIL), and HPV-independent differentiated VIN (dVIN). Traditionally, histology and immunohistochemistry (IHC) have been the basis of diagnosis and classification of VIN. HSIL shows conspicuous histological atypia, and positivity on p16-IHC, whereas dVIN shows less obvious histological atypia, and overexpression or null-pattern on p53-IHC. For both types of VIN, other diagnostic immunohistochemical markers have also been evaluated. Molecular characterization of VIN has been attempted in few recent studies, and novel genotypic subtypes of HPV-independent VSCC and VIN have been identified. This systematic review appraises the VSCC precursors identified so far, focusing on histology and biomarkers (immunohistochemical and molecular). To gain further insights into the carcinogenesis and to identify additional potential biomarkers, gene expression omnibus (GEO) datasets on VSCC were analyzed; the results are presented.

Relocation of inadequate resection margins in the wound bed during oral cavity oncological surgery: A feasibility study

Background

Specimen‐driven intraoperative assessment of the resection margins provides immediate feedback if an additional excision is needed. However, relocation of an inadequate margin in the wound bed has shown to be difficult. The objective of this study is to assess a reliable method for accurate relocation of inadequate tumor resection margins in the wound bed after intraoperative assessment of the specimen.

Methods

During oral cavity cancer surgery, the surgeon placed numbered tags on both sides of the resection line in a pair‐wise manner. After resection, one tag of each pair remained on the specimen and the other tag in the wound bed. Upon detection of an inadequate margin in the specimen, the tags were used to relocate this margin in the wound bed.

Results

The method was applied during 80 resections for oral cavity cancer. In 31 resections an inadequate margin was detected, and based on the paired tagging an accurate additional resection was achieved.

Conclusion

Paired tagging facilitates a reliable relocation of inadequate margins, enabling an accurate additional resection during the initial surgery.

Raman spectroscopy for cancer detection and cancer surgery guidance: translation to the clinics

Oncological applications of Raman spectroscopy have been contemplated, pursued, and developed at academic level for at least 25 years. Published studies aim to detect pre-malignant lesions, detect cancer in less invasive stages, reduce the number of unnecessary biopsies and guide surgery towards the complete removal of the tumour with adequate tumour resection margins. This review summarizes actual clinical needs in oncology that can be addressed by spontaneous Raman spectroscopy and it provides an overview over the results that have been published between 2007 and 2017. An analysis is made of the current status of translation of these results into clinical practice. Despite many promising results, most of the applications addressed in scientific studies are still far from clinical adoption and commercialization. The main hurdles are identified, which need to be overcome to ensure that in the near future we will see the first Raman spectroscopy-based solutions being used in routine oncologic diagnostic and surgical procedures.

Improving clinical diagnosis of early-stage cutaneous melanoma based on Raman spectroscopy

Background

Clinical diagnosis of early melanoma (Breslow thickness less than 0.8 mm) is crucial to disease-free survival. However, it is subjective and can be exceedingly difficult, leading to missed melanomas, or unnecessary excision of benign pigmented skin lesions. An objective technique is needed to improve the diagnosis of early melanoma.

Methods

We have developed a method to improve diagnosis of (thin) melanoma, based on Raman spectroscopy. In an ex vivo study in a tertiary referral (pigmented lesions) centre, high-wavenumber Raman spectra were collected from 174 freshly excised melanocytic lesions suspicious for melanoma. Measurements were performed on multiple locations within the lesions. A diagnostic model was developed and validated on an independent data set of 96 lesions.

Results

Approximately 60% of the melanomas included in this study were melanomas in situ. The invasive melanomas had an average Breslow thickness of 0.89 mm. The diagnostic model correctly classified all melanomas (including in situ) with a specificity of 43.8%, and showed a potential improvement of the number needed to treat from 6.0 to 2.7, at a sensitivity of 100%.

Conclusion

This work signifies an important step towards accurate and objective clinical diagnosis of melanoma and in particular melanoma with Breslow thickness <0.8 mm.

Differentiated vulvar intraepithelial neoplasia (dVIN): the most helpful histological features and the utility of cytokeratins 13 and 17

Differentiated vulvar intraepithelial neoplasia (dVIN) is the precursor lesion of HPV-negative vulvar squamous cell carcinoma (VSCC). The histopathological diagnosis of dVIN can be challenging, as it often resembles vulvar non-neoplastic epithelial disorders (NNED), especially lichen sclerosus (LS). We aimed to establish the most specific and reproducible histological features of dVIN and assessed cytokeratin 13 (CK13) and cytokeratin 17 (CK17) immunohistochemistry as a diagnostic aid. Consecutive cases of dVIN (n = 180) and LS (n = 105) from the period 2010 to 2013 were reviewed using a checklist of histological features. Each feature was recorded as ‘present’ or ‘absent’ and statistical comparison (dVIN vs LS) was made. Interobserver agreement between two pairs of pathologists was assessed for a subset of cases of dVIN (n = 31) and LS and other NNED (n = 23). Immunohistochemistry with CK13, CK17, MIB1 and p53 was performed on dVIN, LS, and other NNED cases. Macronucleoli, features of disturbed maturation and angulated nuclei were significantly more common in dVIN than LS (p < 0.001). We found ‘substantial agreement’ for the diagnosis of dVIN (κ = 0.71). Macronucleoli and deep keratinisation had the highest agreement. In dVIN, the mean percentage of cells staining with CK13 was 15 and with CK17, this was 74. For LS, the mean percentage of cells staining with CK13 was 31, and with CK17, this was 41. By plotting receiver operating characteristic curves (ROC), an area under the curve (AUC) of 0.52 was obtained for CK13, and an AUC of 0.87 was obtained for CK17. The most helpful histological features for diagnosing dVIN were macronucleoli, features of disturbed maturation, and angulated nuclei. Increased CK17 expression may have promise for supporting dVIN diagnosis.

Differences in Rate of Complete Excision of Basal Cell Carcinoma by Dermatologists, Plastic Surgeons and General Practitioners: A Large Cross-Sectional Study

BACKGROUND

Due to the increasing incidence of basal cell carcinoma (BCC) and rising health care costs, health care insurance companies seek ways to shift skin surgery for BCC from secondary to primary care.

OBJECTIVES

To study the differences in complete excision of BCC by general practitioners (GPs), dermatologists, and plastic surgeons.

METHODS

A retrospective cross-sectional study of pathology records of 2,986 standard excisions of primary BCCs performed by a GP, dermatologist, or plastic surgeon in the area of Southwest Netherlands between 2008 and 2014. To compare the risk of an incomplete BCC excision between the specialties, the odds ratio (OR) was used adjusted for patient age, sex, tumor site, size, and histological subtype.

RESULTS

BCCs were completely excised by GPs in 70%, which was lower than the 93% by dermatologists and 83% by plastic surgeons (p < 0.001). Compared to the dermatologist, BCCs which were excised by a GP were 6 times higher at risk of an incomplete excision (adjusted OR 6, 95% CI 5-8) and 2 times higher at risk when excised by a plastic surgeon (adjusted OR 2, 95% CI 2-3).

CONCLUSION

BCCs were more often completely excised by dermatologists than by GPs and plastic surgeons. Dermatologists probably perform better because of their extensive training and high experience in BCC care. To minimize incomplete BCC excision, GPs should receive specific training before the shift of BCC care from secondary to primary care is justifiable.

Relations between Activation and Inhibition of Fibrinolysis in the Walls of Human Arteries and Veins

From systematic studies of both the activation and the inhibition of fibrinolysis in human blood vessels, data which provided insight into the fibrinolysis antagonism along and across the human vessel wall were obtained.

The capacity for fibrinolysis initiated by plasminogen activator in sections of human arteries and veins as demonstrated by the fibrin sfide technique differed greatly along and across the vessel walls. Inhibition of plasmin fibrinolysis in these blood vessels as detected by the fibrin slide sandwich technique was present at sites of low fibrinolytic activity, while inhibition was absent in areas showing strong fibrinolysis. Fibrinolysis was related to endothelial cells, while inhibition of fibrinolysis was brought about by smooth muscle cells. The results indicate that differences in endothelial fibrinolysis may be the result of differences in inhibition of fibrinolysis caused by variations in the number of smooth muscle cells present locally. A systemic decrease in endothelial fibrinolysis observed in endotoxin shock, hyaline membrane disease and a Waterhouse-Friderichsen syndrome appeared to be associated with a systemic increase in inhibition of fibrinolysis not related to smooth muscle cells.

Raman spectroscopy for assessment of bone resection margins in mandibulectomy for oral cavity squamous cell carcinoma

OBJECTIVES

The aim of this study was to investigate the potential of Raman spectroscopy for detection of oral cavity squamous cell carcinoma (OCSCC) in bone resection surfaces during mandibulectomy.

MATERIALS & METHODS

Raman mapping experiments were performed on fresh mandible resection specimens from patients treated with mandibulectomy for OCSCC. A tumour detection algorithm was created based on water concentration and the high-wavenumber range (2800 cm^-1-3050 cm^-1) of the Raman spectra.

RESULTS

Twenty-six ex vivo Raman mapping experiments were performed on 26 fresh mandible resection specimens obtained from 22 patients. The algorithm was applied on an independent test set and showed an accuracy of 95%, a sensitivity of 95%, and a specificity of 87%.

CONCLUSION

These results form the basis for further development of a Raman spectroscopy tool as an objective method for intraoperative assessment of bone resection margins.

A Novel Spectroscopically Determined Pharmacodynamic Biomarker for Skin Toxicity in Cancer Patients Treated with Targeted Agents

Raman spectroscopy is a noninvasive and label-free optical technique that provides detailed information about the molecular composition of a sample. In this study, we evaluated the potential of Raman spectroscopy to predict skin toxicity due to tyrosine kinase inhibitors treatment. We acquired Raman spectra of skin of patients undergoing treatment with MEK, EGFR, or BRAF inhibitors, which are known to induce severe skin toxicity; for this pilot study, three patients were included for each inhibitor. Our algorithm, based on partial least squares-discriminant analysis (PLS-DA) and cross-validation by bootstrapping, discriminated to variable degrees spectra from patient suffering and not suffering cutaneous adverse events. For MEK and EGFR inhibitors, discriminative power was more than 90% in the viable epidermis skin layer; whereas for BRAF inhibitors, discriminative power was 71%. There was a 81.5% correlation between blood drug concentration and Raman signature of skin in the case of EGFR inhibitors and viable epidermis skin layer. Our results demonstrate the power of Raman spectroscopy to detect apparition of skin toxicity in patients treated with tyrosine kinase inhibitors at levels not detectable via dermatological inspection and histological evaluation. Cancer Res; 77(2); 557-65. ©2016 AACR.

Water Concentration Analysis by Raman Spectroscopy to Determine the Location of the Tumor Border in Oral Cancer Surgery

Adequate resection of oral cavity squamous cell carcinoma (OCSCC) means complete tumor removal with a clear margin of more than 5 mm. For OCSCC, 85% of the surgical resections appear inadequate. Raman spectroscopy is an objective and fast tool that can provide real-time information about the molecular composition of tissue and has the potential to provide an objective and fast intraoperative assessment of the entire resection surface. A previous study demonstrated that OCSCC can be discriminated from healthy surrounding tissue based on the higher water concentration in tumor. In this study, we investigated how the water concentration changes across the tumor border toward the healthy surrounding tissue on freshly excised specimens from the oral cavity. Experiments were performed on tissue sections from 20 patients undergoing surgery for OCSCC. A transition from a high to a lower water concentration, from tumor (76% ± 8% of water) toward healthy surrounding tissue (54% ± 24% of water), takes place over a distance of about 4 to 6 mm across the tumor border. This was accompanied by an increase of the heterogeneity of the water concentration in the surrounding healthy tissue. The water concentration distributions between the regions were significantly different (P < 0.0001). This new finding highlights the potential of Raman spectroscopy for objective intraoperative assessment of the resection margins. Cancer Res; 76(20); 5945-53. ©2016 AACR.

Raman Spectroscopic Characterization of Melanoma and Benign Melanocytic Lesions Suspected of Melanoma Using High-Wavenumber Raman Spectroscopy

Melanoma is a pigmented type of skin cancer, which has the highest mortality of all skin cancers. Because of the low clinical diagnostic accuracy for melanoma, an objective tool is needed to assist clinical assessment of skin lesions that are suspected of (early) melanoma. The aim of this study was to identify spectral differences in the CH region of HWVN (high-wavenumber) Raman spectra between melanoma and benign melanocytic lesions clinically suspected of melanoma. We used these spectral differences to explore preliminary classification models to distinguish melanoma from benign melanocytic lesions. Data from 82 freshly excised melanocytic lesions clinically suspected of melanoma were measured using an in-house built Raman spectrometer, which has been optimized for measurements on pigmented skin lesions (excitation wavelength 976 nm and a wavelength range of the Raman signal 1340-1540 nm). Clear spectral differences were observed between melanoma and benign melanocytic lesions. These differences can be assigned mainly to the symmetric CH2 stretching vibrations of lipids. Our results show that the Raman bands between 2840 and 2930 cm(-1) have increased intensity for melanoma when compared to benign melanocytic lesions, suggesting an increase in lipid content in melanoma. These results demonstrate that spectroscopic information in the CH-stretching region of HWVN Raman spectra can discriminate melanoma from benign melanocytic lesions that are often clinically misdiagnosed as melanoma and that Raman spectroscopy has the potential to provide an objective clinical tool to improve the clinical diagnostic accuracy of skin lesions suspected of melanoma.

[Cutaneous ulcerating nodules after many years of immunotherapy]

A 40-year-old female patient was referred to the department of Dermatology with subcutaneous nodules and ulcers years after starting with immunotherapy injections (Purethal) for hay fever. The skin reaction appeared to be due to aluminium hydroxide, which is used as an adjuvant to many injections and vaccins. Aluminium hydroxide can cause delayed granulomatous contact dermatitis or foreign body reactions.

[A woman with cayenne pepper spots]

A 52-year-old female with dyspareunia presented with red-brown maculae at the vulva.Biopsy revealed an inflammatory cell infiltrate mostly consisting of plasma cells, and the diagnosis 'vulvitis circumscripta plasmacellularis' was established.A biopsy is mandatory to confirm this rare benign inflammatory disorder of the vulva.

Lamotrigine hypersensitivity syndrome and spiking Fever

We report a case of a 26 year old woman with rash, lymphadenopathy, liver enzyme abnormalities and spiking fever. She was diagnosed with drug-induced hypersensitivity syndrome (DHS) to lamotrigine. Spiking fever in relation to drug-induced hypersensitivity syndrome has not earlier been described in adults. Spiking fever is an important symptom of the wide spectrum of disease presentation. The syndrome is commonly referred to as either Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) or DHS. In accord with previous authors we see both syndromes as two ends of a spectrum, with a wide range of symptoms and presentations. Therefore we plea for unity in nomenclature.

[Granulomatous secondary syphilis; an uncommon presentation of a polymorphic disease]

BACKGROUND

Due to a great diversity of clinical presentations secondary syphilis can mimic various skin diseases, which means that the diagnosis of this sexually transmitted condition can be missed. Occurrence of a granulomatous inflammatory reaction in secondary syphilis is rare and may be confused with other granulomatous dermatoses.

CASE DESCRIPTION

We present a 37-year-old homosexual male with a granulomatous dermatitis due to secondary syphilis. The differential diagnosis based on clinical and histopathological findings was lengthy and the initial syphilitic serology results were negative, resulting in delayed diagnosis. After revision of the histopathology and repeated serological testing secondary syphilis could be diagnosed.

CONCLUSION

Not only the clinical, but also the histopathological presentation of secondary syphilis is variable. To prevent transmission, treatment delay and complications, we recommend repeating syphilitic serology following negative results if there is clinical or histopathological suspicion of this disease, especially in patients displaying high-risk behaviour. Syphilis should be also excluded in granulomatous dermatoses with plasma cells.

Optical Spectroscopy for the Classification of Malignant Lesions of the Bronchial Tree

Optical spectroscopy may be used for in vivo, noninvasive distinction of malignant from normal tissue. The aim of our study was to analyze the accuracy of various optical spectroscopic techniques for the classification of cancerous lesions of the bronchial tree. We developed a fiberoptic instrument allowing the measurement of autofluorescence spectroscopy (AFS), diffuse reflectance spectroscopy (DRS), and differential path length spectroscopy (DPS) during bronchoscopy. Spectroscopic measurements were obtained from 191 different endobronchial lesions (63 malignant and 128 nonmalignant) in 107 patients. AFS, DRS, and DPS sensitivity/specificity for the distinction between malignant and nonmalignant bronchial lesions were 73%/82%, 86%/81%, and 81%/88%, respectively. All three optical spectroscopic modalities facilitate an increase of the positive predictive value of autofluorescence bronchoscopy for the detection of endobronchial tumors. Even better results were obtained when the three spectroscopic techniques were combined.

Ectopic mesothelial cell proliferation in cervical lymph nodes after severe ovarian hyperstimulation syndrome

OBJECTIVE

To report a case of ectopic mesothelial proliferation in cervical lymph nodes after severe ovarian hyperstimulation syndrome.

DESIGN

Case report.

SETTING

University-affiliated teaching hospital.

PATIENT(S)

A 42-year-old woman underwent a successful IVF attempt and developed severe ovarian hyperstimulation syndrome and pathologically enlarged cervical lymph nodes.

INTERVENTION(S)

Paracentesis, cervical lymph node biopsy followed by cytology, histology, and immunohistochemistry.

MAIN OUTCOME MEASURE(S)

Resolution of symptoms, pregnancy outcome, correct pathological diagnosis.

RESULT(S)

Paracentesis resulted in resolution of symptoms of ovarian hyperstimulation. The diagnosis of ectopic mesothelial proliferation in cervical lymph nodes was made after immunohistochemical examination of cervical lymph nodes. The pregnancy progressed normally, and at 40 weeks the patient spontaneously delivered a healthy son weighing 3,060 g.

CONCLUSION(S)

This case describes ectopic mesothelial cell proliferation localized in and around cervical lymph nodes occurring at 9 weeks' gestation in a patient who earlier developed severe ovarian hyperstimulation syndrome 10 days after ET. Ectopic mesothelial cell proliferation in lymph nodes is an extremely rare event, and this is the first case described after ovarian hyperstimulation. Familiarity with this event is important for the clinician as well as for the pathologist in preventing the misdiagnosis of malignancy.

Measurement of hypoxia-related parameters in bronchial mucosa by use of optical spectroscopy

RATIONALE

Tumor hypoxia has both prognostic and therapeutic consequences for solid tumors. We developed a novel noninvasive technique, differential path-length spectroscopy (DPS), which allows the measurement of hypoxia-related parameters in the superficial microvasculature of tissue.

OBJECTIVES

The aim of this study was to measure the microvascular oxygenation of histologically normal endobronchial mucosa and of neoplastic lesions during bronchoscopy using DPS.

METHODS

Sixty-four patients with known or suspected malignancies of the lung were studied. One hundred and five endobronchial lesions (38 histologically normal, 37 metaplastic/mild dysplastic lesions, and 30 invasive carcinomas) were detected by white and/or autofluorescence bronchoscopy and measured using DPS.

RESULTS

We observed that bronchial tumors are characterized by a lower blood oxygen saturation and a higher blood content than normal mucosa. No differences were observed between normal and metaplastic/mild dysplastic mucosa.

CONCLUSION

DPS is a new optical technique allowing the noninvasive study of endobronchial tumor hypoxia.

Full-blown graft-versus-host disease presenting with skin manifestations, jaundice and diarrhoea: an unusual paraneoplastic phenomenon of a thymoma

We describe a patient who presented with chronic diarrhoea, skin lesions and jaundice. Based on histopathological examinations of the affected organs combined with the clinical features, it appeared that the patient fulfilled the criteria for graft-versus-host disease (GVHD). GVHD occurs especially after allogeneic stem cell transplantation and sometimes after organ transplantations. However, this patient had never undergone such a procedure. Further examination revealed that the patient also suffered from a thymoma, which was concluded to be the cause of GVHD. Unfortunately, the patient died after resection of the thymoma. This patient is probably the second case with thymoma and full-blown GVHD and shows that GVHD can occur in the absence of a previous transplantation.

Relations between activation and inhibition of fibrinolysis in the walls of human arteries and veins

From systematic studies of both the activation and the inhibition of fibrinolysis in human blood vessels, data which provided insight into the fibrinolysis antagonism along and across the human vessel wall were obtained. The capacity for fibrinolysis initiated by plasminogen activator in sections of human arteries and veins as demonstrated by the fibrin slide technique differed greatly along and across the vessel walls. Inhibition of plasmin fibrinolysis in these blood vessels as detected by the fibrin slide sandwich technique was present at sites of low fibrinolytic activity, while inhibition was absent in areas showing strong fibrinolysis. Fibrinolysis was related to endothelial cells, while inhibition of fibrinolysis was brought about by smooth muscle cells. The results indicate that differences in endothelial fibrinolysis may be the result of differences in inhibition of fibrinolysis caused by variations in the number of smooth muscle cells present locally. A systemic decrease in endothelial fibrinolysis observed in endotoxin shock, hyaline membrane disease and a Waterhouse-Friderichsen syndrome appeared to be associated with a systemic increase in inhibition of fibrinolysis not related to smooth muscle cells.

Activators and inhibitors of fibrinolysis in rheumatoid and nonrheumatoid synovial membranes. A histochemical study

Histochemical studies of rheumatoid and nonrheumatoid synovial membranes revealed lowered fibrinolytic activity at sites of chronic inflammatory infiltrates and deposits of fibrin-like material (FLM). Inhibition of fibrinolysis occcurred over these areas and was always inversely related to the fibrinolytic activity. Hence the low fibrinolytic activity of these chronically inflamed tissues seems to result from the presence of inhibitors of fibrinolysis. Such inhibitors in FLM deposits may be responsible for the prolonged persistence of these deposits in the rheumatoid joint.

Distribution and variation of fibrinolytic activity in the walls of human arteries and veins

A systematic study on the location and intensity of the fibrinolytic activity in more than 500 samples of human arteries and veins from 50 routine necropsies and 35 blood vessel biopsies was performed. Data were obtained for an overall comparison of the fibrinolytic activity along and across the walls of human blood vessels by the use of a standardized fibrin slide technique. Arteries generally showed little or no fibrinolytic activity in the intima and media but strong activity in the adventitia. Veins showed a comparable strong fibrinolytic activity in the external layer of loose connective tissue. Fibrinolytic activity in the venous intima, media and adventitia was generally weaker but varied greatly according to position in the body. Veins situated in the lower parts of the body had less fibrinolytic activity than the veins at the upper levels. Fibrinolytic activity was found to be related to the endothelium of the vasa vasorum and/or of the main lumen of the vascular wall. Increased fibrinolytic activity was observed in arteries and veins in cases of sudden death, vasogenic shock, cerebral hemorrhage and cirrhosis. Decreased fibrinolytic activity was encountered in blood vessels in cases of endotoxin shock, hyaline membrane disease and a case of Waterhouse-Friderichsen syndrome.

Fibrinolytic activity in aneurysmal bone cysts

Euglobulin fibrinolytic activity of cyst fluid from six patients with aneurysmal bone cysys was considerably higher than that of arterial and venous blood of the corresponding patients. The high fibrinolytic activity was associated with a very low concentration of fibrinogen and a low concentration of plasminogen. Correspondingly, a high plasminogen activator activity was found in cyst tissue related to endothelial lining. It is suggested that fibrinolysis is an important factor in the maintenance and expansion of the aneurysmal bone cyst.

Inhibition of fibrinolysis by the human vascular wall related to the presence of smooth muscle cells

The fibrin slide sandwich technique is a histochemical method for the detection and localization of inhibition of fibrinolysis in tissues. By this technique it was demonstrated that plasmin inhibition is present in the human vascular wall. The great diversity in the pattern and the capacity for inhibition among different parts of the vascular system appeared to be in close association with the localization and number of smooth muscle cells present in this system. The postulated relationship between fibrinolytic inhibition and smooth muscle cells was strongly supported by the demonstration of a similar inhibition of fibrinolysis in other human tissues containing a high number of smooth muscle cells.