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M Boysen

Publications and source records attributed to M Boysen.

At least 55 records · Page 3Linked to original sources
PubMed1994

Rates of regression and progression of dysplastic lesions in the nasal mucosa in nickel workers: a Markov model approach.

Nasal epithelial dysplasia is considered a precancerous state. From 1976 through 1989, regular screening for such lesions has been performed among workers at the Falconbridge nickel refinery in Kristiansand. The longitudinal data thus obtained have been evaluated to ascertain to what extent, if any, pre-existing dysplasia can regress when exposure to nickel is reduced. A total of 418 pairs of observations were available from 243 workers. Interpretation of the data is complicated by the fact that dysplasia may remain undetected in small biopsies and the probability of detection of existing dysplasia was, therefore, incorporated into the two-state Markov model. Transition probability rates were estimated by maximum likelihood. The results suggest that regression of dysplasia has taken place and that regression rates increased with time. This finding probably reflects a decreased exposure resulting from a combination of a reduction in airborne nickel, improved personal hygiene and allocation of workers with dysplasia to work in areas with lower nickel exposure. Our results indicate that the chance of developing carcinomas related to nickel exposure is reduced. There are, however, indications that dysplasias continue to develop at a low rate.

Humans↗
PubMed1994

Squamous cell carcinoma of the respiratory tract following laryngeal papillomatosis.

With the object to disclose an association between laryngeal papillomatosis and laryngeal carcinoma, we reviewed 102 patients with laryngeal papillomatosis treated between 1950 and 1979. Seven cases of laryngeal carcinomas were recorded and 1 patient with spread of papilloma to the bronchial tree developed a bronchial carcinoma. The time between onset of papilloma and diagnosis of carcinoma was 4-55 years (mean 24 years). For laryngeal carcinoma the ratio of observed to expected cases was 88. Of the 8 patients developing respiratory tract carcinoma, 2 had received treatment with radiation and 2 had been treated with Bleomycin. Four of these 8 patients were known smokers. This study shows that papillomatosis is more often associated with laryngeal carcinoma than previously reported. It appears, however, that laryngeal papillomas alone seldom induce carcinomas. Apart from irradiation and smoking, Bleomycin could be an important co-factor.

Adolescent↗
PubMed1994

Prognostic significance of contrast enhancement and tumor demarcation at CT of squamous cell carcinomas of the oral cavity and oropharynx.

A retrospective analysis of the CT examinations of 45 patients with squamous cell carcinomas of the tongue, floor of the mouth and tongue base with long-term follow-up is presented. The aim of the study was to determine whether differences in tumor contrast enhancement and tumor demarcation at contrast-enhanced CT were correlated to prognosis in terms of posttreatment residual tumor or local recurrence. Ill-defined tumor margins were by means of multiple regression analysis significantly correlated to local failures (p = 0.043). This feature was, however, not associated with a significant decreased survival. The degree of tumor contrast enhancement did not parallel variations in the histopathologic composition of the tumors.

Adult↗
PubMed1993

Fistulae following laryngectomy in patients treated with irradiation.

The development of fistulae following 197 consecutive laryngectomies performed from 1980 to 1987 have been examined. Fistulae were present in 28 patients (14 per cent). Age, T-classification, daily level of radiation dose and the time lapse between diagnosis and operation did not seem to influence the rate of fistula development. The study indicates that there is a two to three per cent risk of fistula development when a primary laryngectomy is performed. Fistula formation increased to about 10 to 12 per cent following radiotherapy, with an additional increase whenever previous operations on the neck had been done and/or if the disease demanded more extensive surgery. The study also indicates that the risk for fistula development is less when an experienced surgeon performs the operation.

Adult↗
PubMed1993

Second malignant neoplasms in patients with head and neck squamous cell carcinomas.

The incidence of second malignant neoplasms (SMN) was analyzed in 714 patients with squamous cell carcinomas of the oral cavity, oropharynx, hypopharynx and larynx. With a minimum follow-up of 3.5 years and 2,540 person-years at risk 84 SMN (10 synchronous and 74 metachronous) developed in 81 patients. The relative risk of SMN was 2.4. The actuarial method showed an annual incidence of SMN of 3.5%. For oral cavity and oropharyngeal tumors the annual incidence of SMN was 4.0% and 3.8% respectively, compared to 2.1% for laryngeal cancer (p < 0.013 and 0.017 respectively). Sex, age or stage of the index tumor did not significantly influence the annual incidence of SMN. After 3 years of follow-up, SMN became more a cause of concern than loco-regional relapse.

Actuarial Analysis↗
PubMed1992

Quantitative histopathological evaluation of vocal cord dysplasia with particular emphasis on nuclear orientation.

We have applied morphometry on formaldehyde-fixed, H & E-stained diagnostic laryngeal biopsies from 7 patients with mild dysplasia and 7 with severe dysplasia/carcinoma in situ, in search of objective parameters required for reproducible histopathological grading of epithelial dysplasias. Special emphasis has been put upon the individual nuclear polarity as a spatial variable. Also included were 4 specimens with normal epithelium. By means of a semiautomatic digitizing tablet, the nuclear and epithelial area, formfactor and the polarity variation between the longitudinal axes of adjacent nuclei were measured in the basal, parabasal, middle and luminal layers of the epithelium. N:C-ratio, mean values of nuclear area, formfactor or their coefficient of variation could not distinguish between mild and severe dysplasia. The variations in neighboring nuclear polarity, however, revealed a highly significant distinction between mild and severe dysplasia (p less than 0.001). This parameter may therefore have diagnostic potential.

Biopsy↗
PubMed1992

The value of follow-up in patients treated for squamous cell carcinoma of the head and neck.

Clinical findings, treatment and results have been recorded prospectively in 661 patients with carcinoma of the head and neck. With an average follow-up of 3 years 7813 follow-up consultations revealed 220 recurrences. The overall "recurrence pick-up rate" and subsequent "cure rate" was 1:36 and 1:113 consultations, respectively. Laryngeal carcinomas treated with radiotherapy and oral carcinomas receiving radiotherapy and limited resections showed recurrence "cure-rates" of 1:89 and 1:110, respectively. For other tumour sites the average "cure-rate" was 1:238. Only 39% of the recurrences were detected through physical examination. Follow-up consultations revealed 9.1% of second primaries. More time should be spent on training patients to recognise symptoms and signs of recurrence. Routine follow-up is rarely indicated beyond the third year after completion of treatment, or in patients for whom we have little to offer in terms of curative treatment.

Adult↗
PubMed1992

An improved technique for treating tracheostomal stenosis following laryngectomy.

Stenosis of the tracheostome is an occasional complication following laryngectomy. Having tried a number of procedures recommended for correction of such stenoses with limited results, we developed a new technique. This technique which is based on multiple Y-V plasties has been applied to 20 patients. Measurements of the stomal area following surgery in 18 patients showed an average increase in stomal size by a factor of 3.8. One patient apparently had no increase of the stoma. In 2, no post-operative measurements were available. Post-operative infection resulted in recurrence of the stenosis in one patient. He was successfully reoperated using the same technique. Follow-up revealed that none of the patients had complaints related to their stoma.

Adult↗
PubMed1992

Elective radiotherapy of the neck in patients with squamous cell carcinoma of the head and neck.

A prospectively recorded 5-year series of 254 patients receiving elective neck irradiation is evaluated. All had clinically negative necks and initial control at the primary site. Forty-seven percent of the patients had T3-4 tumours. Radiotherapy was delivered from a megavolt source at 2 Gy/day 5 days a week to a total dose of 46-50 Gy. All but 3 patients completed the treatment as planned. Neither tumour stage nor site of the primary tumour was related to the incidence of regional recurrences. Of 30 patients receiving 46-49 Gy, 5 died from neck node recurrences. Of 221 patients treated to 50 Gy or more, 16 (7.2%) developed regional recurrences. Two of these recurrences were avoided, giving a regional failure rate of 6.3%. As a whole, 7.8% died from regional, 11.4% from local, and 3.1% from distant recurrences.

Adult↗
PubMed1992

Combined radiotherapy and surgery in the treatment of neck node metastases from squamous cell carcinoma of the head and neck.

A prospectively recorded series of 107 patients with clinical neck node metastases from head and neck squamous cell carcinomas, treated in 1983-1988, and with initial local control, is evaluated. Eighty-eight patients received preoperative, and were operated 4-6 weeks after radiotherapy, and 19 received postoperative radiotherapy. Forty-four of the neck specimens in the preoperatively treated patients showed vital tumor tissue, 7 with positive and 37 with negative resection margins. Nine of the latter 37 patients died due to regional recurrence. Twenty-three of the preoperatively treated patients had no palpable residual tumor following radiotherapy, but histological examination showed vital tumor tissue in five, of whom two had N1 neck disease. The overall regional failure rate was 19%. Eleven patients (10%) died from local recurrence and 11 from distant metastases. Forty-one patients (38%) are alive without evidence of disease and three (3%) alive with disease (mean observation time 30 months). Combined treatment is recommended for all cases of neck node metastases.

Adult↗
PubMed1992

Towards 3-D modelling of epithelia by computer simulation.

The present work is a preliminary step towards dynamic 3-D modelling by computer graphics simulation of the structure of normal and pathological epithelia, using an expert system. In its present state, Esexsy (Epithelium Simulation by EXpert SYstem) allows the construction, through iterative steps, of a simple 3-D representation of the nasal epithelium, based on the positions, sizes and shapes of nuclei. The iterative process is based on statistical comparisons between distributions of parameter values calculated from real (2-D) histological sections and those issued from an equivalent computer 'section' through the simulated 3-D image. We show the results of attempts at simulating normal, metaplastic and dysplastic states of the nasal epithelium, the latter two being characterized by a progressive architectural disorganization, accompanied by nuclear size/shape alterations. The representation takes into account the size, shape, orientation and spatial arrangement of nuclei, with one or several layers from the basal lamina to the lumen. A modified Poisson point process is used at present to position the nuclei, which are modelled by bi-axial spheroids (from prolate to oblate through spherical), with random orientation and size/shape deviations. It should be possible to use the same computer program to simulate other types of epithelia and to achieve increasingly realistic representations by incorporating, notably, nuclear deformations and chromatin texture.

Computer Graphics↗
PubMed1992

CT and MR imaging of primary tumors of the masticator space.

A retrospective study of CT and MR examinations in 14 patients with benign and malignant tumors originating in the masticator space is presented. At presentation, 12 patients revealed tumor extension to adjacent regions and spaces. Perineural tumor spread along trigeminal nerve branches to the cavernous sinus and orbits was combined with facial pain, and/or numbness, ophthalmoplegia, and exophthalmus. Detailed analysis of tumor growth and spread, enhancement and signal features at CT and MR imaging indicated the tumor histology was, with a few exceptions, nonspecific. More extensive growth and bone destruction was noted only among malignant tumors. MR imaging was found superior to CT in delineating tumor extension due to better soft tissue contrast resolution and multiplanar imaging. Posttreatment examinations were available in 11 patients and showed long-standing regional edema of the adjacent temporal lobe and masticator muscles in 4 out of 5 patients without clinical evidence of tumor. In 6 patients, CT and MR features were found almost unchanged with only small size differences after various forms of treatment.

Adolescent↗
PubMed1992

How often is dysplasia diagnosed by biopsy or smear examination? Application of a maximum likelihood based method to the assessment of detection rates in the nasal mucosa of nickel workers.

In view of the known increased risk of nasal carcinoma and the high prevalence of dysplastic lesions of the nasal mucosa among nickel workers, regular screening for the existence of possibly precancerous dysplastic lesions is offered to workers in a Norwegian nickel refinery. Unfortunately, available sampling techniques do not allow the identification of all subjects in whom dysplastic changes are present. Independent histological and cytological (brush cytology) diagnoses, obtained for each of a group of 90 workers, have been used to estimate, by a maximum likelihood method, the probabilities that existing dysplastic lesions will be detected by each of these two screening methods. In the group studied, cytology performed rather less well than histology in unambiguously detecting dysplasia. However, when cytological specimens showing irregular (possibly dysplastic) epithelial cells were grouped with those showing clear dysplastic changes, detection probabilities were estimated at 0.52 by histology and 0.57 by cytology. Detection probabilities were estimated to be higher among subjects with a previously known history of dysplasia, particularly by histology (P < 0.01), probably due to larger dysplastic areas. In view of both its greater facility and speed of sampling, and its greater acceptability, brush cytology may be preferable to biopsy sampling for the screening of large numbers of workers at risk.

Biopsy↗
PubMed1991

Carcinoma in situ of the larynx: an evaluation of its natural clinical course.

The outcome of 75 patients with severe dysplasia or carcinoma in situ of the larynx has been reviewed. The patients were divided into three groups according to treatment; Group A (16 patients) had received irradiation. Group B (24 patients) had developed invasive carcinoma less than 1 year after the diagnosis of carcinoma in situ and Group C (41 patients) had been observed for more than 1 year, receiving no treatment other than repeat biopsies. Of the latter group, 46% developed invasive carcinoma of the vocal cords, with a mean observation time of 51 months. Mean age at the onset of the disease was 66 years in patients where the epithelium returned macroscopically to normal during observation compared to 59 years in patients who developed carcinoma (P less than 0.05). This may indicate that subgroups of carcinoma in situ exist with different biological behaviour. No extra benefit was seen for the patients who received irradiation for carcinoma in situ, and close follow-up with, eventually, stripping of the epithelium is therefore advocated. Both altered anatomical site during observation and an increase in area of the lesion should be regarded as a warning signal.

Carcinoma in Situ↗
PubMed1991

The nasolabial skinflap in intraoral reconstruction.

Twenty-four patients underwent reconstruction of the lower anterior part of the oral cavity with a total of 29 nasolabial skinflaps, following ablative surgery for squamous cell carcinoma. Partial necrosis due to biting occurred in one flap. The rest healed without complications. Cosmetic impairment was minimal and postoperative functional problems were related to the extent of the primary resection rather than the flap. The nasolabial flap has proved to be a very safe and useful alternative for reconstruction of relatively small defects in the lower anterior part of the oral cavity.

Aged↗
PubMed1990

[Neck metastases from an unknown primary tumor].

We evaluate 41 patients treated for cervical lymph node metastases from occult primary carcinomas. Minimum follow-up was two years. 18 patients had metastases from squamous cell carcinoma, 12 from undifferentiated and 11 from adenocarcinoma. The survival rate was best for patients treated with surgery and radiation. The survival rate was 66% for patients with squamous cell and undifferentiated carcinoma, compared with 20% for patients with adenocarcinoma. The survival rate was 85% for patients with N1 and N2A metastases (UICC 1987) from squamous cell and undifferentiated carcinoma, compared with 45% for patients with metastases classified as N2B-N3. The prognosis was better for patients with tumors in the upper 2/3 of the neck than for patients with metastases in the lower 1/3 of the neck. We emphasize the significance of fine-needle aspiration biopsy as a highly accurate, safe and valuable technique in diagnosing malignant tumors of the head and neck.

Adult↗