PubMed Health⌕ Search

Biomedical subjects

H J Prins

Publications and source records attributed to H J Prins.

6 recordsLinked to original sources
PubMed2001

Testicular microlithiasis, a premalignant condition: prevalence, histopathologic findings, and relation to testicular tumor.

OBJECTIVES: To perform a retrospective analysis concerning the prevalence of testicular microlithiasis (TM). In patients with TM, the association of TM with testicular tumor, histopathologic findings, and follow-up were studied. METHODS: During a 6-year period at the Central Military Hospital or the University Medical Center in Utrecht, The Netherlands, ultrasonography of the testis was performed in 1535 patients. Patient records, ultrasound images, and histopathologic specimens were reviewed. Follow-up was performed in patients with TM. RESULTS: In 63 patients (4.1%), with a mean age of 35.4 years (range 19 to 74), TM was diagnosed at ultrasonography. In 29 of these patients (46%), a concomitant testicular tumor was diagnosed. A statistically significant correlation was found between TM and the presence of a testicular tumor (P <0.001; chi-square test). No significant correlation was found concerning the respective positions of the TM and the tumor in the testis, type of calcification, and histologic type of the tumor. In 34 patients, TM was found without a malignancy at diagnosis (mean age 39.2 years; range 19 to 69). Follow-up was possible in 31 patients. During the follow-up period (median 61.8 months), 1 patient developed a testicular tumor. CONCLUSIONS: A correlation was found between TM and testicular tumor. Because an increasing number of studies have reported patients with TM who developed a testicular tumor, TM should be regarded as a premalignant condition, which necessitates follow-up. Urologists should consider testis biopsy in patients with TM.

Adult↗
PubMed1994

MR diagnosis of paraganglioma of the head and neck: value of contrast enhancement.

OBJECTIVE: Contrast enhancement with gadopentetate dimeglumine has been advocated to increase the efficacy of MR imaging for paragangliomas of the head and neck. However, contrast media are expensive, time-consuming to use, and involve minimal but not negligible risks. The purpose of this study was to determine if the use of contrast material is warranted in patients undergoing MR imaging for the diagnosis of paragangliomas of the head and neck. MATERIALS AND METHODS: Unenhanced MR images were compared with images obtained after administration of gadopentetate dimeglumine in 23 healthy subjects and 37 patients who had a total of 71 tumors. Three combinations of sequences were reviewed independently and in a random order by four observers who had no clinical information. Combination A comprised enhanced and unenhanced T1-weighted sequences, combination B comprised unenhanced T1- and T2-weighted sequences, and combination C was a combination of all sequences. A four-point scale of certainty was used. CT, scintigraphic, angiographic, and surgicopathologic findings were used as the standard of reference. Results were subjected to alternative free-response receiver-operating-characteristic (AFROC) scoring and statistical analysis. RESULTS: The mean areas under the AFROC curve for combinations A, B, and C were 0.761, 0.856, and 0.827, respectively. Mean sensitivity/specificity values after dichotomizing the scoring results were 0.73/0.94, 0.79/0.95, and 0.78/0.94 for combinations A, B, and C, respectively. The performance of combinations B and C did not differ markedly, but both combinations were significantly better than combination A. In a relatively large percentage (36%) of small postoperative tumor residues not detected on unenhanced images, however, gadopentetate dimeglumine allowed detection. CONCLUSION: The results of this study indicate that, in general, the use of gadopentetate dimeglumine is not necessary for the detection of head and neck paragangliomas. The addition of contrast-enhanced imaging does not increase the sensitivity or specificity compared with imaging without enhancement. Only when searching for small postoperative tumor residues is the addition of gadopentetate dimeglumine warranted.

Adult↗
PubMed1977

Lumbar myelography with metrizamide.

Experiences with lumbar myelography with metrizamide (Amipaque) are reported. A less strict post-examination routine is presented. The subjective side effects do not seem to differ from those reported after lumbar puncture alone.

Humans↗