PubMed Health⌕ Search

Biomedical subjects

P Knegt

Publications and source records attributed to P Knegt.

At least 19 recordsLinked to original sources
PubMed2000

Inflammatory pseudotumor of the fossa pterygopalatina: diagnosis and treatment.

Pseudotumor is a term used to describe a space-occupying inflammatory lesion of unknown etiology that clinically simulates a neoplastic process. Pseudotumors of the fossa pterygopalatina and fossa infratemporalis are very rare. In this paper, we describe a patient who developed a pseudotumor in the left fossa pterygopalatina, secondary to an unclassified autoimmune disease, which caused progressive left-sided facialdynia and swelling. The tumor was detected with somatostatin receptor scintigraphy. The lesion was refractory to steroids, also in combination with azathioprine, as well as to surgical intervention. An excellent clinical response was observed after cyclosporine was added. This case is presented here in order to draw attention to the use of somatostatin receptor scintigraphy as a diagnostic tool in visualizing pseudotumors and to document a case that responded excellently to treatment with a combination of low-dose cyclosporine and steroids.

Bone Diseases↗
PubMed1999

Management of inverted papilloma via Denker's approach.

Denker's approach was used in the management of 78 patients presenting with an inverted papilloma of the nasal sinus complex between the years 1986 and 1993 at the University Teaching Hospital in Rotterdam. The recurrence rate was 9% with a mean follow-up after surgery of 56 months. There was minimal morbidity and no mortality associated with the procedure. Three patients had a squamous cell carcinoma associated with the inverted papilloma. The results of our study indicate that Denker's approach has a similar or lower recurrence rate than an open external approach to papilloma and is a safe procedure with minimal morbidity.

Carcinoma, Squamous Cell↗
PubMed1998

The value of ultrasound with ultrasound-guided fine-needle aspiration biopsy compared to computed tomography in the detection of regional metastases in the clinically negative neck.

PURPOSE: Head and neck oncologists have not reached consensus regarding the role of contemporary imaging techniques in the evaluation of the clinically negative neck in patients with head and neck squamous cell carcinoma (HNSCC). The purpose of the present study was to compare the accuracy of ultrasound with guided fine-needle aspiration biopsy (UGFNAB) and computed tomography (CT) in detecting lymph node metastasis in the clinically negative neck. METHODS AND MATERIALS: Sixty-four neck sides of patients with HNSCC were examined preoperatively by ultrasound/UGFNAB and CT at one of five participating tertiary care medical centers. The findings were correlated with the results of histopathologic examination of the neck specimen. RESULTS: Ultrasound with guided fine-needle aspiration biopsy was characterized by a sensitivity of 48%, specificity of 100%, and overall accuracy of 79%. Three cases had nondiagnostic aspirations using UGFNAB and were excluded. CT demonstrated a sensitivity of 54%, specificity of 92%, and overall accuracy of 77%. UGFNAB detected two additional metastases not visualized on CT, whereas CT detected no metastases not seen on UGFNAB. The results of UGFNAB were similar between the participating centers. CONCLUSIONS: Approximately one half of the clinically occult nodal metastases in our patient group were identified by both CT and UGFNAB. Overall, UGFNAB and CT demonstrated comparable accuracy. The sensitivity of CT was slightly better than UGFNAB, but the latter remained characterized by a superior specificity. The results of CT and UGFNAB did not appear to be supplementary. The choice of imaging modality for staging of the clinically negative neck depends on tumor site, T-stage, and experience and preference of the head and neck oncologist. If CT is required for staging of the primary tumor, additional staging of the neck by UGFNAB does not provide significant additional value.

Biopsy, Needle↗
PubMed1998

Ultrasound in the diagnosis of cervical tuberculous adenitis.

Ultrasound (US) of cervical tuberculous adenitis (CTA) was demonstrated to produce a characteristic pattern of the affected nodes in the majority of the patients in this study. The contribution of US to the diagnosis and assessment of CTA is evaluated. It is concluded that, since the other diagnostic tests for CTA are not reliable and/or time-consuming, the demonstration of nodal calcifications, conglomerate nodal masses and spread into the subcutaneous tissues at US in patients with elusive cervical masses may result in earlier recognition of CTA.

Adult↗
PubMed1997

Continuity of information in cancer care: evaluation of a logbook.

A logbook, or patient-dossier, was developed, to improve continuity of information in the treatment and care of head-and-neck cancer patients. It contained information modules on different aspects of care, as well as forms to facilitate communication both between patient and care-professional and between the various care-professionals. The logbook's effectiveness was evaluated in two hospitals in Rotterdam, by comparing outcomes for trial and comparison groups of, respectively, 71 and 54 patients and 59 and 35 care-professionals. Trial patients proved to be better informed, to receive more support and to experience fewer psychosocial problems. Professionals who used the logbook were better informed about their patients, and about the care-activities of fellow-professionals than those who did not. They recognised an improvement in their contact with colleagues and in the harmonisation of their respective care-activities.

Aged↗
PubMed1996

Regional metastasis in head and neck squamous cell carcinoma: revised value of US with US-guided FNAB.

PURPOSE: To verify the acclaimed accuracy of ultrasound (US) combined with US-guided fine-needle aspiration biopsy (FNAB) in the detection of lymph node metastasis in the neck and to evaluate the interobserver variability. MATERIALS AND METHODS: In a prospective, multicenter study of 185 patients with head and neck squamous cell carcinoma, US (n=238 neck sides) with US-guided FNAB (n=178 neck sides) was used for evaluation of the lymph node status of the neck. Findings were correlated with those of histopathologic examination in 238 neck sides. RESULTS: US with US-guided FNAB had a sensitivity of 77% and a specificity of 100%. Nineteen of 178 aspirations were nondiagnostic. There were no significant differences between the four participating hospitals or the individual sonologists (P>.05). CONCLUSION: Sensitivity of US with US-guided FNAB was slightly lower compared with previous reports. Specificity was similar to previous reports. Interobserver variability appeared to be low. The validity of US with US-guided FNAB is high and warrants widespread use of the procedure for evaluation of the neck.

Adult↗
PubMed1995

Cervical metastasis from the unknown primary tumor.

A retrospective study was performed to examine the results of treatment for cervical lymph node metastases from an unknown primary between 1978 and 1988. We reviewed 66 patients treated with either surgery and/or radiotherapy (n = 41), radiation therapy and chemotherapy (n = 11), combined modality treatment with surgery (n = 8) or with management delayed to proven disease (n = 6). The male-to-female ratio was 5.6 to 1, and the median age was 64 years (range, 15-89 years). Intercurrent death-corrected 5-year survival was 50%. The most important prognostic factors were M category and involvement of supraclavicular nodes. Primary tumor was eventually discovered in 12 patients during follow-up, 6 of whom received treatment with curative intent. The most common site of primary tumor was found to be the lung (n = 5).

Adolescent↗
PubMed1995

Immunotherapy with monoclonal antibodies directed against the immunosuppressive domain of p15E inhibits tumour growth.

Immunosuppressive retrovirus-related proteins, like p15E, are involved in tumour-associated immunosuppression. In the present study we investigated whether such proteins could be used as targets in tumour immunotherapy using MoAbs. Immunotherapy was performed in mice inoculated with the Rauscher virus-transformed myeloid cell line RMB-1. RMB-1 cells express retroviral antigens at their cell surface. In order to obtain constant serum titres of MoAbs over a prolonged period of time during therapy, anti-p15E antibody-producing hybridoma cells were encapsulated in alginate and injected intraperitoneally in tumour-bearing mice. Using this technique, serum antibody titres of 50-100 micrograms/ml were obtained, which remained constant over a period of at least 3 weeks. Therapy experiments were performed using anti-p15E antibodies 19F8, which recognizes both cell surface-associated as well as circulating p15E, and ER-IS5, which did not react with surface-bound p15E beyond background, but which neutralizes circulating p15E. Inoculation of alginates containing anti-p15E hybridoma cell lines in RMB-1 tumour-bearing mice showed inhibition of tumour cell growth. In survival experiments, 19F8 cured eight of 23 tumour-bearing mice. The p15E neutralizing antibody ER-IS5 caused a significant longer survival, but therapy with this MoAb alone was not sufficient to cure the animals of the RMB-1 tumour.

Alginates↗
PubMed1994

New monoclonal antibodies against the putative immunosuppressive site of retroviral p15E.

Both retroviral infections as well as human tumors may cause immunosuppression. One of the factors involved in immunosuppression in patients with squamous cell carcinoma of the head and neck (SCC-HN) is a protein related to the retroviral protein p15E. A conserved, 17-amino acid sequence represents the immunosuppressive epitope of retroviral p15E. In order to study the relationship between SCC-HN associated immunosuppression and retroviral p15E, we produced three new monoclonal antibodies (MAbs; ER-IS1, ER-IS2, and ER-IS5) directed against the immunosuppressive synthetic CKS-17 peptide. These MAbs react with the immunosuppressive peptide (in enzyme-linked immunosorbent assay), with human tumor cell lines (in FACScan analysis), with retroviral p15E (on Western blot), and with cryostat sections of SCC-HN tumor tissue. In addition, the MAbs neutralize the immunosuppressive low molecular weight factors present in sera of patients with SCC-HN. These results show that retroviral p15E and the immunosuppressive factors associated with SCC-HN share a conserved immunosuppressive epitope and that MAbs against this epitope can be used for detection and neutralization of the tumor-associated immunosuppressive protein(s).

Amino Acid Sequence↗
PubMed1994

Transantral orbital decompression for Graves' disease.

Seventy-five patients with Graves' disease have been treated by transantral orbital decompression. In the first post-operative month the average reduction in proptosis was 3 mm. In the years following the operation this reduction increased to an average of 4.5 mm. In 32% of the patients without diplopia before surgery, the diplopia that developed afterwards did not disappear, 83% of them were successfully treated by extraocular muscle surgery. Seventy per cent of the patients experienced immediate post-operative improvement of visual acuity. Only three patients remained with anaesthesia of the infra-orbital nerve. A total of 65% of the patients found the operation procedure beneficial while 76% were satisfied with the ophthalmological result. We conclude, that transantral orbital decompression, though with moderate morbidity, gives good results in patients with the orbital complications of Graves' disease.

Adolescent↗
PubMed1993

Reduction of the number of neck treatments in patients with head and neck cancer.

With modern diagnostic imaging techniques, the head and neck oncologist is faced with increasing information on the status of neck nodes of patients with head and neck cancer. It is often difficult to include this new diagnostic information in clinical management because strategies of neck treatment date from times when only clinical examination was available. Computed tomography, magnetic resonance imaging, and ultrasonography (US) may provide information on the status of neck nodes. In the University Hospital Leiden and the University Hospital Rotterdam, US of the neck, when combined with ultrasonographic fine-needle aspiration biopsy (US-UGF-NAB), has proved to be an accurate diagnostic test for nodal disease. The combined procedure is characterized by high sensitivity and specificity. Therefore, this technique is suited for detecting, demonstrating, and excluding nodal metastases. This article will discuss how to interpret the new diagnostic information supplied by US-UGFNAB. A different approach in the clinical management of the neck, based on techniques from the field of clinical decision analysis, will be presented. It is concluded that US-UGFNAB is a promising concept of methodic use of both cytologic examination and an imaging technique in the examination of patients with squamous cell carcinoma of the upper aerodigestive tract. Application of the test may produce an accurate classification of patients with a head and neck tumor and change indications for elective and therapeutic neck treatment.

Biopsy, Needle↗
PubMed1991

Ultrasound-guided fine-needle aspiration biopsy of neck nodes.

The assessment of nodal involvement in patients with squamous cell carcinoma of the head and neck is still a major diagnostic problem. Although the sensitivity of imaging techniques for detection of neck nodes is gradually improving, the specificity for metastases remains low. Cytologic examination could, theoretically, supply additive information. Computed tomographic-and magnetic resonance-guided aspiration techniques have been described, but these were not efficacious and laborious. In 1984, we developed a technique for ultrasound-guided (UG) fine-needle aspiration biopsy (FNAB). This technique is described herein, and the value of UGFNAB is compared with conventional FNAB. All statistical characteristics of UGFNAB appeared to be superior to conventional FNAB (sensitivity, 98% vs 88%; specificity, 95% vs 82%; positive predictive value, 98% vs 93%; negative predictive value, 95% vs 74%; and accuracy, 97% vs 87%). Furthermore, UGFNAB was characterized by less nondiagnostic aspirations. It is concluded that UGFNAB is a reliable technique for differentiation between benign nodes and cervical lymph node metastases and it may, therefore, contribute to a more accurate assessment of the neck in squamous cell carcinoma of the head and neck.

Biopsy, Needle↗
PubMed1990

Ultrasound-guided percutaneous drainage of deep neck abscesses.

Deep neck abscesses may still result in significant morbidity and mortality. Surgical therapy carries the risk of damage to cranial nerves and arteries. Excellent results of ultrasound-guided percutaneous catheter drainage of abdominal abscesses led us to apply this technique to the management of deep neck abscesses. Five patients were treated with ultrasound-guided catheter drainage and antibiotics. All patients were cured without complications or recurrences. We consider this cheap and highly effective treatment as a valuable alternative to conventional therapy.

Abscess↗
PubMed1989

Metastatic neck disease. Palpation vs ultrasound examination.

Nodal disease is a diagnostic problem in head and neck oncology. Current methods for investigation of the neck are not satisfactory as far as differentiation between necks with positive nodes and those with negative nodes is concerned. In the present study, the results of palpation and ultrasound examination were compared with histopathologic examination results of 120 neck dissection specimens. Furthermore, the value of ultrasound examination, combined with cytologic examination, of neck nodes was evaluated. Ultrasound examination was characterized by high sensitivity, ie, 96.8%; specificity was 32.0%. When the results of ultrasound-guided fine-needle aspiration biopsy were added to the ultrasound findings, specificity was as high as 92.9%. From these results, it was concluded that ultrasound examination with fine-needle aspiration biopsy is an accurate method for assessment of the neck in head and neck oncology.

Biopsy, Needle↗
PubMed1989

Evaluation of treatment results of squamous cell carcinoma of the buccal mucosa.

Of the 49 patients with squamous cell carcinoma of the buccal mucosa referred to the Rotterdam Radio-Therapeutic Institute (RRTI) and Universital Hospital Dijkzigt Rotterdam (AZD) during 1970-1984, 31 patients had an advanced stage of disease, 21 patients had clinical evidence of lymph node metastasis. Forty patients were treated with curative intention. Treatment modalities were: radiation therapy, preoperative radiation followed by surgery, and primary surgery. Eighteen of the 40 patients (45%) developed a local tumor recurrence; nearly all recurrences occurred within 2 years. The incidence was equal in all treatment groups. Of the 22 patients with initial clinically negative neck, regional relapse occurred in 3 of the 14 patients, of whom the neck was not treated electively by radiation therapy; all three in combination with a local recurrence. None of the 8 patients with electively irradiated necks developed a regional relapse. Eight of the 18 patients with initial clinically enlarged lymph nodes treated either by radiotherapy or surgery, developed a regional relapse, 5 in combination with a local recurrence. Treatment of the clinically positive neck by neck dissection was superior to radiotherapy. Local recurrence carried a poor prognosis. Almost 70% died of their disease. The overall and corrected 5-year survival was 38% and 52% respectively.

Carcinoma, Squamous Cell↗
PubMed1988

Operative treatment of median cervical cysts.

Median cervical cysts are congenital anomalies arising from remaining thyroglossal duct epithelium. A major problem in the surgical treatment of these cysts is the high frequency of recurrence. Embryonic considerations indicate an important causal role for the hyoid bone in these recurrences. We studied the relationship between operative techniques and the number of recurrences in 36 patients treated in our hospital. Fourteen patients sent from other hospitals had a recurrent fistula; in thirteen cases the hyoid bone was still in place. All patients who had the central part of the hyoid bone excised were cured. In 14 patients without adequate excisions of the hyoid bone we found four recurrences. To prevent recurrence a total excision of thyroglossal duct epithelium is necessary.

Adolescent↗