Biomedical subjects
Publications and source records attributed to B A Lowe.
Solitary metastases are not unusual in renal adenocarcinomas. Vaginal metastases occur but rarely and are the cause of presentation in most patients. Because of the tumor's similarity to other primary gynecologic tumors, the patients present difficult diagnostic and management problems, as shown by the case reported here.
Inflammatory pseudotumor (pseudosarcoma) of the bladder is a benign proliferative lesion of the submucosal stroma easily mistaken for a malignant neoplasm clinically and histologically. The lesion was first described as a separate entity in a report of 2 patients. Three additional cases have been reported since then. We describe pseudosarcomatous bladder tumors arising in 2 adolescents. Both patients presented with sudden onset of gross painless hematuria related to large polypoid and ulcerated bladder masses found on endoscopy. Initial pathological analysis was interpreted as poorly differentiated sarcoma in both patients but subsequent reviews were consistent with a benign process resembling nodular fasciitis. Simple excision in both patients has been successful in eradicating the lesion. The findings in these 2 patients are described with a discussion of the pathophysiology and review of the literature.
A comparison is made of laser anastomoses of the murine vas deferens at different energies with the neodymium (Nd):YAG laser at 1.06 micron and 1.318 micron and with the CO2 laser. A total of 28 welds were performed with a free-hand technique employing a 600-micron silicon fiber with the Nd:YAG and a hand piece with a 500-micron spot size for the CO2. After 6 weeks, all animals were sacrificed and the vasa evaluated for patency. Fifteen out of 28 controls repaired with microsurgical techniques were found to be patent; 4/10 vasa were patent with use of the Nd:YAG at 1.318 micron at laser energies of 300 mW and 500 mW. At 1.06 micron, only 1/4 anastomoses was patent at a power setting of 1 W. None of the anastomoses performed with the CO2 laser was patent. Histologic study revealed intense fibrosis in all the lasered vasa, with sperm granuloma formation associated with most anastomoses. Although this is a preliminary study, it appears that the Nd:YAG laser at 1.318 micron and a power setting of 300-500 mW provides patency rates superior to the Nd:YAG at 1.06 micron and to the CO2 lasers and is equivalent to standard micro-surgical techniques in the murine vas deferens.
Incidentally discovered prostatic cancer can pursue a benign clinical course or it can rapidly progress. Differentiating those tumors with low biological potential from more aggressive lesions has been the focus of many reports. To define more completely the variables that can be used to predict those patients with low biological potential requiring limited treatment from those needing more extensive therapy, a retrospective study of 232 patients with incidentally discovered cancer was undertaken. Progressive disease was used as an endpoint for statistical analysis with the Kaplan-Meier technique and Cox's multiple hazard regression mode. This extensive analysis of multiple parameters demonstrated a significant advantage of survival free of disease for patients presenting with tumors manifesting a lower Gleason score and volume extent. Probability tables were constructed to allow for prediction of the probability of progression for a given patient with incidentally discovered prostate cancer directly related to patient age at diagnosis, Gleason score, and initial volume extent of the tumor. With these tables a logical therapeutic approach can be derived for each patient in an attempt to maximize survival free of disease with minimal intervention.
For the patient with incidentally discovered prostatic cancer that has a high probability of progression further treatment may be indicated. Several studies have shown that survival free of disease is increased by additional therapy but the choice of treatment remains unclear. The lack of matched controls has prevented rigid statistical analysis of the efficacy of prostatectomy and radiotherapy or expectant management in the treatment of these tumors. A prior review of 251 patients with stage A prostate cancer provided a population base from which to perform a matched pair analysis between 30 control patients receiving no additional treatment and 30 patients treated by either prostatectomy or radiotherapy. A second and unpaired analysis was performed among patients undergoing radical prostatectomy (17), radiotherapy (31) and expectant management alone (33). The treated group achieved a significantly superior survival free of disease over the matched control group managed expectantly. The unpaired analysis again demonstrated the advantages of treatment over no treatment but failed to define a clear statistical difference between the 2 treated groups. Radical prostatectomy appeared to provide a recognizable advantage over radiotherapy in survival free of disease but was not statistically significant owing to the small size of the sample population.
We report 2 cases of recurrent superficial papillary transitional cell carcinoma of the bladder with right vesicoureteral reflux in which superficial papillary transitional cell carcinoma developed in the distal ureter with reflux. Both patients received intravesical mitomycin C that was delivered by the vesicoureteral reflux to the tumor sites. Diagnosis and management were facilitated through the use of ureteroscopy, which allowed for accurate pathological staging and surveillance. No systemic toxicity or change in renal function was noted in either patient and both have remained free of recurrent tumor for more than 2 years.
Infectious processes in the retroperitoneal space often involve the psoas muscle. These infections usually are secondary to other intra-abdominal or intrapelvic inflammatory processes but rarely they will arise primarily within the retroperitoneum. These primary infections occur most often in younger patients and usually will demonstrate a chronic illness in which the diagnosis often is missed. We describe a 22-year-old man with a 2-year history of symptoms before the diagnosis was confirmed. The clinical presentation of the process and pathophysiology are discussed briefly.
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Radiographic procedures performed at a 100-bed pediatric hospital were reviewed jointly by a radiologist and the primary physician staff. The reviewers judged several procedures to be performed unnecessarily, with undue patient risk or cost. Low efficacy examinations were divided into two categories: (1) low-yield examinations with significant gonadal radiation as well as significant cost, and (2) low-yield examinations with low gonadal radiation but significant cost. A joint policy recommendation was then delivered to the house staff concerning appropriate indications for the performance of these low-yield procedures. This active review process is submitted as a model for other medical facilities that seek to reduce risk and cost to the pediatric patient.
In a previous study using dogs whose renal function was rendered asymmetric by unilateral infarction, the efficacy of technetium-99m (99mTc) DTPA and DMSA in measuring differential glomerular filtration rate (GFR) was demonstrated. The present study was undertaken to determine whether the same techniques were applicable to unilateral ureteral obstruction. Five normal dogs and nine dogs with partial unilateral ureteral obstruction had determination of glomerular filtration rate by standard techniques using constant infusions of iothalamate and creatinine after ureteral catheterization. These results were compared with total GFR as measured by single injection of 99mTc DTPA and analysis of the plasma disappearance curve. Calculated differential GFR was obtained by multiplying total GFR from double exponential analysis of this curve (DTPA2) by each of three measures of differential function. These included the percent differential uptake of 99mTc DTPA and 99mTC DMSA in the posterior projection as well as the geometric mean of 99mTc DMSA uptake. There were good correlations between differential GFR determined by iothalamate clearances at ureteral catheterization and all noninvasive methods involving radionuclides and DTPA2 ( r = 0.93-0.99). Single exponential analysis of the 99mTc DTPA plasma disappearance curve was less satisfactory than double exponential analysis. These results and those reported previously support the use of radionuclides in the determination of differential GFR in a variety of clinical situations.