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Biomedical subjects

L R Bégin

Publications and source records attributed to L R Bégin.

At least 19 recordsLinked to original sources

Priapism secondary to penile metastasis: a report of two cases and a review of the literature.

Malignancy metastasis to the penis is an uncommon clinicopathological entity. We present two cases of malignant priapism following penile metastasis, in which the diagnosis was established by core needle biopsy of the corpus cavernosum. Primary tumors were urothelial carcinoma of the urinary bladder in one case (the patient having concomitant high-grade prostatic adenocarcinoma) and prostatic adenocarcinoma in the other. The clinicopathological features of 51 previously reported cases of penile metastasis in the recent literature are reviewed.

Adenocarcinoma

Renal carcinoid and horseshoe kidney: a frequent association of two rare entities--a case report and review of the literature.

We report the case of a primary renal carcinoid tumor associated with a horseshoe malformation in a 43-year-old man who presented with testicular pain. The tumor was centrally located and purely solid and had features ascribed to hindgut neuroendocrine neoplasia. The relative risk of developing a carcinoid tumor in a horseshoe kidney is estimated to be x82.

Adult

Perineurioma of the finger: case report of a rare peripheral nerve sheath neoplasm of pure perineurial cell lineage.

A 1.9-cm extraneural soft tissue tumor located on the palmar aspect of the index finger of a 50-year-old woman was excised. Depicting many histopathologic patterns and a full range of cellularity, the tumor was exclusively composed of epithelial membrane antigen/vimentin-positive and S-100 protein/Leu-7-negative neoplastic cells of perineurial lineage. Soft tissue (extraneural) perineurioma, a rare variant of benign peripheral nerve sheath tumor, should be included in the differential diagnosis of tumor and tumor-like conditions affecting soft parts of the hand.

CD57 Antigens

Family with Graves disease, multinodular goiter, nonmedullary thyroid carcinoma, and alveolar rhabdomyosarcoma.

Benign thyroid disease is a risk factor for nonmedullary thyroid carcinoma [Houlston and Stratton: Q J Med 88:685-693, 1995]. We report on a family with 7 members with benign and/or malignant thyroid neoplasia; one affected female died of a paravertebral alveolar rhabdomyosarcoma at age 20. The occurrence of thyroid nodular hyperplasia, nonmedullary thyroid cancer, and rhabdomyosarcoma in the same family may be due to chance, common environmental factors, or, most likely, genetic predisposition.

Adolescent

Influence of BRCA1 mutations on nuclear grade and estrogen receptor status of breast carcinoma in Ashkenazi Jewish women.

BACKGROUND: In the Ashkenazim, three recurrent germline mutations have been identified in the breast carcinoma susceptibility genes BRCA1 and BRCA2: 185delAG, 5382insC (BRCA1), and 6174delT (BRCA2). The frequency of these mutations in the general Ashkenazi population approaches 2%. There is little available controlled data comparing the characteristics of breast carcinoma arising in BRCA1 mutation carriers or BRCA2 mutation carriers with that arising in noncarriers, although such data would be relevant to the urgent clinical need to develop risk-reduction strategies for individuals at increased risk due to genetic factors. METHODS: The authors screened 149 unselected tumors arising in Ashkenazi Jewish women for the 185delAG, 5382insC, and 6174delT mutations and compared tumors arising in mutation carriers with tumors arising in noncarriers with respect to nuclear grade, steroid hormone receptor status, and axillary lymph node status. RESULTS: In the 149 cases, the authors found 17 BRCA1 mutations (11.4%; 95% confidence interval [ci], 6.8-17.6%), and 4 6174delT BRCA2 mutations (2.7%; 95% CI, 0.8-6.7%). Tumors from women with BRCA1 mutations were significantly less likely to be estrogen receptor positive (age-adjusted odds ratio [or]: 0.091; P < 0.001) and more likely to have a high nuclear grade (OR: 5.55; P 0.001) than tumors in which no mutation was identified. All four BRCA2 positive breast carcinoma specimens were estrogen receptor positive. CONCLUSIONS: Breast carcinoma arising in Ashkenazim BRCA1 mutation carriers has adverse prognostic features relative to those arising in noncarriers in the same population. This may be relevant to the development of prevention and treatment strategies for these women. For example, if tamoxifen reduces the risk of breast carcinoma via its antiestrogenic effects, it is possible that this effect will be diminished in the largely estrogen receptor negative BRCA1-related hereditary breast carcinoma.

Adult

Outcome of sextant biopsy according to gland volume.

OBJECTIVES: To reassess positive rate of sextant biopsy according to gland size. METHODS: We evaluated 1974 consecutive men with systematic sextant biopsy, among whom we examined biopsy yield according to gland-volume intervals of 10 cc. RESULTS: Decreasing yield of sextant biopsy is strongly associated with increasing gland volume (P < 0.001). Highest biopsy rate (39.6%) was recorded among men with prostates smaller than 20 cc. The lowest biopsy rate (10.1%) was recorded among men with prostates between 80 and 89.9 cc. Among men with biopsy-proven cancer, age, serum prostate-specific antigen, and Gleason grade were comparable (P > 0.05) throughout the range of gland-volume intervals. CONCLUSIONS: Our findings suggest that gland size represents an important determinant contributing to the yield of sextant biopsy in men at risk of harboring a nonpalpable, isoechoic cancer. Consequently, an individualized sector biopsy approach, based on prostate volume, may warrant consideration because it may ensure superior detection of clinically significant disease among all men at risk, regardless of prostate size.

Adult

Morphologic changes induced by neoadjuvant androgen ablation may result in underdetection of positive surgical margins and capsular involvement by prostatic adenocarcinoma.

OBJECTIVE: Neoadjuvant androgen ablation (NAAA) causes significant cytoarchitectural changes in both benign and malignant prostatic epithelial cells that may contribute to underdetection of prostate cancer capsular involvement and positive surgical margins. METHODS: The aim of this study is to determine the ability of cytokeratin immunohistochemistry to enhance the determination of pathologic stage of prostate cancer following NAAA. RESULTS: Cytokeratin AE1/AE3 immunohistochemistry identified 6 (27.3%), 15 (68.2%), 5 (22.7%), and 5 (22.7%) cases of organ-confined disease, capsule penetration, positive surgical margin, and seminal vesicle involvement, respectively, as compared with 10 (45.5%), 10 (45.5%), 3 (13.6%), and 5 (22.7%) cases by hematoxylin-eosin (H&E) staining, respectively. Two cases without detectable tumor by H&E staining had demonstrable residual tumor by cytokeratin immunohistochemical staining. CONCLUSIONS: Cytokeratin immunohistochemistry revealed more extensive intracapsular, capsular, and extracapsular tumor involvement and higher rate of positive surgical margin than did conventional H&E staining. Therefore, the beneficial pathologic effects of NAAA observed may, in part, be attributable to the artifact of observation.

Adenocarcinoma

Evaluation of a no-needle penile injector: a preliminary study evaluating tissue penetration and its hemodynamic consequences in the rat.

OBJECTIVES: Intracavernous needle injection is an effective delivery method for pharmacotherapy of erectile dysfunction. Needle phobia, pain, and concern about local tissue injury have stimulated the search for new, less invasive means of inducing penile erection. In this preliminary communication, we evaluate a jet injector as an alternative to needle injection for intracavernous delivery of vasoactive drugs. METHODS: Jet injection was evaluated in three groups of rats receiving either India ink, saline, or papaverine into the penis. The ability of the jet injection to penetrate through the tunica albuginea and deliver liquid to the corpora cavernosa smooth muscle was assessed by the degree of staining within the corpus cavernosum (ink group), histologic change (saline group), and rise in intracavernous pressure (papaverine group). Erectile capacity following cavernous nerve electric stimulation was compared before and 1 hour after injection of saline or papaverine. RESULTS: Ink traversed the skin and tunica albuginea with extensive deposition noted within the cavernous spaces. Varying degree of subcutaneous hemorrhage were seen with saline jet injection; however, the corpus cavernous smooth muscles showed no evidence of injury. Jet injection of papaverine 3250 micrograms significantly increased cavernous pressure (39.4 +/- 4.6 cm H2O) compared with saline injection (2.8 +/- 1.3 cm H2O). CONCLUSIONS: We conclude that acute jet injection is an effective method for intracavernous delivery of drugs. Long-term effects should be evaluated prior to clinical use.

Animals

Florid soft-tissue decidual reaction: a potential mimic of neoplasia.

While undergoing a repeat Caesarian section, a 21-year-old woman was found to have a subcutaneous, 3.5-cm tumor-like lesion in the abdominal wall. It had a lobulated contour and consisted of gelatinous tan nodules with intervening fibrous septa. It had a composite histology, including a solid pattern of large glassy cells with a predominant perivascular and pericystic/cisternal topography (35% surface area); a pattern of dyscohesive, vacuolated cells including physaliphorous-like forms (35% surface area); and a myxoid pattern of spindle to stellate cells showing frequent cell contact and lying within an optically clear or pale eosinophilic and bubbly extracellular matrix with a prominent capillary framework. A strong and diffuse cytoplasmic expression of vimentin (only) was present in all cytoarchitectural patterns. The extracellular matrix and intracytoplasmic vacuoles contained abundant acid mucosubstance, mostly hyaluronic acid. No distinct endometrial gland, stigma of hemorrhage, or nuclear estrogen/progesterone receptor protein expression was observed. There were variously sized and shaped cystic spaces lined by a flat to cuboidal cytokeratin-positive cell lining and focally containing neutral and acid mucosubstance. These spaces are interpreted as dilated endometrial glands rather than mechanically entrapped inclusions of mesothelial origin. In this setting, florid decidual reaction represents a potential diagnostic pitfall because it could be confused with more commonly encountered myxoid or epithelioid tumors of mesenchymal, epithelial, or melanocytic cell lineage.

Abdominal Neoplasms

Reassessment of nonplanimetric transrectal ultrasound prostate volume estimates.

OBJECTIVES: To assess the accuracy and reproducibility of nonplanimetric transrectal ultrasound (TRUS) volume estimates because inaccurate volume estimates may potentially undermine the value of serum prostate-specific antigen density (PSAD) in early prostate cancer detection. METHODS: We prospectively evaluated 535 consecutive male patients with two consecutive volume determinations performed by the same ultrasonographer at the time of the same visit. RESULTS: Pearson correlation coefficients between two consecutive gland volume estimates ranged from 0.82 to 0.85 depending on the formula used; however, these correlation coefficients corresponded to an average 25% difference between the first and second gland volume estimates. CONCLUSIONS: Although two consecutive nonplanimetric TRUS volume estimates show statistically good correlation, clinically up to a 25% volume difference should be expected between two such volume estimates. In consequence, nonplanimetric TRUS volume estimates should be interpreted with caution, especially when used for PSAD calculation, in the early detection of prostate cancer.

Adult

Neurogenic erectile dysfunction: the course of nicotinamide adenine dinucleotide phosphate diaphorase-positive nerve fibers on the surface of the prostate.

OBJECTIVES: Nitric oxide (NO) plays an important role as a neurotransmitter in the peripheral neural regulation of erection. A histochemical stain able to localize fibers releasing NO in combination with an in vivo study were used to evaluate the course and physiologic significance of the nerve fibers innervating the cavernous smooth muscle. METHODS: Morphologic studies in 6 rats and 6 human cadavers were performed, tracing the course of branches of the cavernous nerve branches using a nicotinamide adenine dinucleotide phosphate diaphorase staining technique. Electrostimulations in rats were performed before and after transection of the anterolateral part of the prostate capsule. RESULTS: Multiple nerve fibers were documented running on the lateral and ventral surfaces of the prostate distinct from the classically described dorsolateral neurovascular bundle. Transection of these fibers resulted in a loss of electrically induced intracavernous pressure (59.4 +/- 5.6 cm H2O versus 27.0 +/- 4.6 cm H2O). CONCLUSIONS: These preliminary morphologic and physiologic studies support a significant role for these nerve fibers in erection.

Animals

Vasoactive intestinal peptide and impotence in experimental diabetes mellitus.

OBJECTIVE: To determine whether a defect in vasoactive intestinal peptide (VIP)-mediated vasodilatation underlies diabetic impotence. MATERIALS AND METHODS: Rats treated with streptozotocin for 8 weeks developed diabetes, as shown by hyperglycaemia and glycosuria, and had significant impairment of sexual function, as determined by tests of sexual behavior. The VIP content of the penis and major pelvic ganglion, the VIP release by the penis in vitro and the responsiveness of the vasculature of the penis in vivo to intracavernous VIP injection were determined. RESULTS: In diabetic rats, the VIP content of the major pelvic ganglion and penis was markedly increased, while the acetylcholine content of the penis was normal. The amount of VIP released in vitro by high potassium concentration or veratridine was similar for penile tissue slices of normal and diabetic rats. Intracavernous injection of VIP induced erection in the control rats but not in diabetic rats, whereas intracavernous injection of the adenylate-cyclase activator forskolin produced erection in both control and diabetic rats. CONCLUSION: Because VIP induces vasodilatation by activating adenylate cyclase, and forskolin produced erection in the diabetic rats, the failure of VIP to produce erection in these rats is unlikely to be due to a defect in the second-messenger mechanism or in the properties of vascular smooth muscle. Thus, a defect at the level of the VIP receptor or of the associated G-protein possibly explains the failure of intracavernous VIP to produce erection in the diabetic rats. Hence, an abnormality in VIP is a component of sexual dysfunction in the diabetic rat and the defect is at the level of the VIP receptor or associated G-protein.

Acetylcholine

Metastatic carcinoma resulting in hepar lobatum.

Hepar lobatum is an acquired liver deformity mostly known as the end-stage of tertiary syphilis. The authors report two cases of hepar lobatum resulting from metastatic mammary ductal carcinoma in the liver and reassess the clinicopathologic features of seven previously reported cases (two in the German language). A liver of near-normal weight with an irregularly lobulated contour, capsular indentations/crevices from which intersecting (carcinoma-bearing) fibrous septa extended deep into the parenchyma, a predominant centrifugal distribution of lesional areas, and many septa abutting on the degenerated center of tumor nodules were the salient gross features. No significant tumor/fibrous occlusion of intrahepatic branches of portal or hepatic veins, nor cirrhotic type nodular hepatocellular regeneration was observed. Both of these patients experienced a drastic decrease in CEA serum levels during multiagent palliative chemotherapy. In one patient, abundant macrophages in conjunction with minimal residual tumor were present within intrahepatic septa. The pathogenesis of this condition appears largely related to an active phase of chemo-induced tumor regression with subsequent tissue collapse, followed by an organizing phase of healing and scar contraction.

Adult