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Biomedical subjects

R T Gregor

Publications and source records attributed to R T Gregor.

At least 37 records · Page 2Linked to original sources
PubMed1995

Fibromatosis of the head and neck.

Fibromatosis is a locally infiltrative fibrous tissue proliferation with a tendency to recur locally. From a large series of head and neck patients treated between 1977 and 1994 in our institute, we retrieved the records of nine adult patients diagnosed with this disease. They serve as examples to demonstrate this rare entity in the head and neck. Five out of nine lesions were localized in level V (posterior triangle of the neck). The majority of patients were treated by surgery in combination with radiotherapy. None of the patients died of the disease.

Adult↗
PubMed1995

Carcinoma of the pyriform sinus: a retrospective analysis of treatment results over a 20-year period.

One hundred and one patients with pyriform sinus carcinoma treated at the Netherlands Cancer Institute were studied retrospectively. The patients were staged according to the UICC criteria of 1987: there were no stage I, 23 stage II, 30 stage III, and 48 stage IV patients. The treatment consisted of radiotherapy (n = 45), a planned combination of surgery and post-operative radiotherapy (n = 47) or surgery alone (n = 9). The crude 5-year survival was 27%, whereas the 5-year disease-free survival was 37%. The locoregional disease-free survival was 52%. Stage according to the UICC 1987 criteria is an important prognostic variable (P = 0.0026). Furthermore, significantly less locoregional recurrences and a better disease-free survival were seen in the combined surgery and radiotherapy group than in the exclusively irradiated group (P < 0.0001).

Adult↗
PubMed1994

Myxoma of the paranasal sinuses.

Myxomas of the paranasal sinuses are rare but well described in the literature. They may be related to dental malformations or missing teeth, but may also occur without any such abnormalities. Their local aggressiveness and ability to erode bone should not be underestimated, and they should be totally removed whenever possible. A case of myxoma of the sinuses is described, in which recurrence followed several local removals. The patient was only cured by radical maxillectomy. The operation is described, and the literature on the subject reviewed.

Female↗
PubMed1994

Merkel cell carcinoma of the head and neck.

Merkel cell carcinoma is a rare cutaneous tumour that typically arises in the head and neck area of elderly patients. The tumour often follows an aggressive course with frequent local recurrences and (regional) metastases, especially when localized above the clavicles. Five patients with a Merkel cell carcinoma of the head and neck, treated in our institute since 1984, are presented, illustrating the need for radical initial treatment consisting of surgery and radiotherapy, and showing how rapidly progressive the disease can be. Four of the five patients were cured of disease by a combination of surgery and radiotherapy.

Aged↗
PubMed1994

Carcinoma arising in thyroglossal remnants.

Three patients with a papillary carcinoma arising in a thyroglossal duct cyst are presented and the literature is reviewed. This rare malignancy is seen mostly in women between the ages of 20 and 50 years. The distribution of carcinoma subtypes differs from that of thyroid carcinomas and thyroglossal duct carcinoma is recognized as a primary tumour. The diagnosis is seldom made pre-operatively though especially in older patients with midline swellings in the neck the diagnosis should be considered. Sistrunk's operation is the treatment of choice. In this operation the cyst, the middle part of the hyoid bone and the thyroglossal duct are removed in continuity.

Adult↗
PubMed1994

Rosai-Dorfman disease of the paranasal sinuses.

A 57-year-old man presented with a history of nasal obstruction of five to six years duration. 'Nasal polyps' were removed on several occasions. He had previously had an episode of paraplegia which resolved after the removal of a spinal tumour. Histology from both sites was thought to represent a malignant fibrous histiocytoma. On presentation the patient had computed tomographical (CT) evidence of extensive ethmoidal disease, with threatened intracranial extension. He also had evidence of lung and retroperitoneal disease with pancreas and kidney involvement. The ethmoidal disease was considered potentially lethal and therefore a craniofacial resection was performed. Review of all the histology revealed that the diagnosis was extranodal Rosai-Dorfman disease (sinus histiocytosis). The patient's course is described, and the literature on this disease of unknown aetiology is reviewed.

Histiocytosis, Sinus↗
PubMed1993

Myxomas of the mandible and maxilla.

Myxomas of the mandible and maxillary sinus are rare but well described neoplasms. They appear to be odontogenic in origin related to malformations or missing teeth. Their local aggressiveness and ability to erode bone should not be underestimated. Based on our experience we feel that conservative surgical management including total excision and sparing of uninvolved structures allows for preservation of function. Long-term follow-up is necessary and in case of recurrence, a more radical procedure may have to be performed for this benign disease.

Adult↗
PubMed1990

Alkaline phosphatase and phosphoamino acid phosphatases in normal and cancerous tissues of the human larynx.

The activities of alkaline phosphatase and phosphoamino acid phosphatases were measured in normal and cancerous regions of the human larynx. For each larynx, alkaline phosphatase and phosphotyrosine phosphatase activities were higher in the tumor than in the corresponding normal tissue. Phosphothreonine and phosphoserine phosphatase activities were relatively low and there were no consistent trends. The increased alkaline phosphatase activity in the tumors supports histological observations that ossification of cartilage seems to occur at the site of invasion; the phosphatase acting on phosphotyrosine could serve as a regulator of cell differentiation during tumorigenesis.

Adult↗
PubMed1990

Ventriculosaccular carcinoma of the larynx.

The question of whether or not carcinoma arises in the ventricles and saccules of the larynx is a controversial one. These areas of the larynx have pseudostratified columnar ciliated epithelium. In the past several authors have not believed that carcinomas arise in these areas because of the absence of squamous metaplasia in their observations. However, other workers have been convinced that such tumours do arise and that they behave in certain specific ways. In order to clear up the controversy, these areas were studied in 154 laryngeal specimens examined by a serial sectioning technique. In this study 14.3% of the laryngeal specimens studied showed clear evidence of tumour emanating from these areas. Areas of squamous metaplasia with carcinoma in situ and frank invasion have been observed in many of these cases. These tumours spread by concentric enlargement within the paraglottic space and are often diagnosed late since they are difficult to observe from above. Patients who present with hoarseness and a mucosa-covered swelling in the false cord area should be carefully examined if a carcinoma arising in this area is not to be missed.

Adult↗
PubMed1988

The use of carbon dioxide laser in dealing with fibrous strictures of the larynx and trachea.

The carbon dioxide laser has proved valuable in treating patients with severe scarring of the pharynx and supraglottic larynx. There is minimal re-scarring, and an open operation may be avoided. In conjunction with an open procedure, the laser provides a good method of controlling granulation tissue. Two cases of complete pharyngeal stenosis, resulting from caustic ingestion, are described. In one case, repair was achieved by supraglottic laryngectomy and gastro-hypopharyngeal transposition which temporarily obscured the larynx completely. The laser was used to re-open the laryngeal airway, following which the patient had normal eating, breathing and speaking.

Adolescent↗
PubMed1987

Framework invasion by laryngeal carcinoma.

Invasion of the laryngeal framework by cancer implies a tumor that has spread beyond the bounds of the organ of origin, which may affect the outcome of the disease. Framework invasion almost invariably takes place in ossified or calcified cartilage, and the reason for this has never before been adequately explained. The finding of increased density on some computerized tomography scans where the tumor was invading the framework stimulated this study of the mechanisms of this type of spread. One hundred fifty-eight consecutive laryngeal specimens were examined by a serial sectioning method to elucidate this. Several laryngeal specimens were examined for alkaline phosphatase in the tissues, and two specimens were examined for collagenase. A method of tetracycline labeling was used to measure the amount of osteoblastic activity in another two specimens. Framework invasion occurred mainly at the glottic level and exclusively in ossified or calcified cartilage. This type of invasion was associated with osteoblastic activity which appeared to be at least partially mediated by tumor-produced alkaline phosphatase. Osteoclastic activity took place hand-in-hand with the former process, and at this stage, tumor remained outside the perichondrium. Tetracycline labeling confirmed active bone deposition in these areas and appeared to explain the finding of increased ossification seen on computerized tomography scans where early invasion was taking place.

Humans↗
PubMed1985

Trapezius osteomyocutaneous flap for mandibular reconstruction.

The recent introduction of myocutaneous flaps has kindled the interest in including bone in the flap to reconstruct the anterior mandibular arch and floor of mouth--still one of the most challenging reconstructions in head and neck surgery. The trapezius osteomyocutaneous compound flap has certain advantages over other osteomyocutaneous flaps; the scapula, being a flat bone, receives relatively more blood supply from the periosteum. The absence of bone resorption at more than two years postoperatively has been encouraging, and it has been possible to reconstruct mandible from angle to angle.

Adult↗