Thomas B. Crotty

CHROMOPHOBE CELL RENAL CARCINOMA: CLINICOPATHOLOGICAL FEATURES OF 50 CASES

PURPOSE We review the clinicopathological features of chromophobe cell renal carcinoma. MATERIALS AND METHODS Cases were identified by reviewing the histology of all renal neoplasms resected between 1977 and 1990. Clinical data were obtained by chart review. RESULTS Of 50 cases a majority (53%) were discovered incidentally and most (86%) were stage I. Typical pathological findings included the presence of 2 cell types (pale and eosinophilic), reactivity for Hales colloidal iron, ultrastructural cytoplasmic vesicles and deoxyribonucleic acid aneuploidy. At last followup 47 patients (94%) were tumor-free or dead of unrelated causes. Survival was similar in patients with clear cell carcinoma of similar grade and stage. CONCLUSIONS Chromophobe cell carcinoma is a morphologically distinctive neoplasm with a favorable prognosis. Distinction from renal oncocytoma is important.

Efficacy of Contralateral Prophylactic Mastectomy in Women With a Personal and Family History of Breast Cancer

PURPOSE To estimate the efficacy of contralateral prophylactic mastectomy in women with a personal and family history of breast cancer. PATIENTS AND METHODS We followed the course of 745 women with a first breast cancer and a family history of breast and/or ovarian cancer who underwent contralateral prophylactic mastectomy at the Mayo Clinic between 1960 and 1993. Family history information and cancer follow-up information were obtained from the medical record, a study-specific questionnaire, and telephone follow-up. Life-tables for contralateral breast cancers, which consider age at first breast cancer, current age, and type of family history, were used to calculate the number of breast cancers expected in our cohort had they not had a prophylactic mastectomy. RESULTS Of the 745 women in our cohort, 388 were premenopausal (age < 50 years) and 357 were post- menopausal. Eight women developed a contralateral breast cancer. Six events were observed among the premenopausal women, compared with 106.2 predicted, resulting in a risk reduction of 94.4% (95% confidence interval [CI], 87.7% to 97.9%). For the 357 postmenopausal women, 50.3 contralateral breast cancers were predicted, whereas only two were observed, representing a 96.0% risk reduction (95% CI, 85.6% to 99.5%). CONCLUSION The incidence of contralateral breast cancer seems to be reduced significantly after contralateral prophylactic mastectomy in women with a personal and family history of breast cancer.

Expression and Function of Recombinant Endothelial Nitric Oxide Synthase Gene in Canine Basilar Artery

Endothelial NO synthase (eNOS) is an enzyme responsible for the production of a potent vasodilator and a key regulator of vascular tone, NO. In peripheral arteries, expression of a recombinant eNOS gene increases production of NO in the blood vessel wall. This approach appears to be a promising strategy for gene therapy of cerebrovascular disease. The major objective of the present study was to determine whether a recombinant eNOS gene (AdCMVNOS) can be functionally expressed in cerebral arteries. Replication-defective recombinant adenovirus vectors encoding bovine eNOS and Escherichia coli beta-galactosidase (AdCMVLacZ) genes, driven by the cytomegalovirus promoter, were used for ex vivo gene transfer. Rings of canine basilar artery were incubated with increasing titers of the vectors in MEM. Twenty-four or forty-eight hours after gene transfer, expression and function of AdCMVNOS were evaluated by (1) immunohistochemical staining, (2) isometric tension recording, and (3) cGMP radioimmunoassay. Transfection with AdCMVNOS resulted in the expression of recombinant eNOS protein in the vascular adventitia and endothelium, associated with significantly reduced contractile responses to UTP and enhanced endothelium-dependent relaxation to calcium ionophore A23187. Basal production of cGMP was significantly increased in the transfected vessels. The reduced contractions to UTP with increased cGMP production were reversed by a NOS inhibitor, N(G)-monomethyl-L-arginine. Contractions to UTP or production of cGMP were not affected in arteries transfected with AdCMVLacZ reporter gene. The results of the present study represent the first successful transfer and functional expression of recombinant eNOS gene in cerebral arteries. Our findings suggest that cerebral arterial tone can be modulated by recombinant eNOS expression in the vessel wall.

Cytogenetic analysis of six renal oncocytomas and a chromophobe cell renal carcinoma. Evidence that -Y, -1 may be a characteristic anomaly in renal oncocytomas.

Renal oncocytomas are benign tumors whose morphologic features may sometimes be confused with those of certain low-grade malignant neoplasms of the kidney, e.g., chromophobe cell and granular cell variants of renal carcinoma. The presence of a specific genetic abnormality might help differentiate these tumors. Because very few cytogenetic studies of renal oncocytomas have been published, we investigated a consecutive series of six such tumors. We also performed chromosome analysis on a chromophobe cell carcinoma because cytogenetic analyses of this tumor have not been previously reported. Tumor cell metaphases were analyzed after mechanical and enzyme disaggregation, in situ culture, and robotic harvesting. Clonal abnormalities were present in five of the six oncocytomas, and loss of chromosome 1 with loss of the Y chromosome occurred in two. Review of the literature disclosed four other renal oncocytomas with the 44,X,-Y,-1 karyotype. In the chromophobe cell carcinoma, we noted an abnormal clone with a del(11)(p12p15.1); similar anomalies were not observed in the renal oncocytomas. We conclude that renal oncocytomas have clonal chromosome abnormalities and that a subgroup of these tumors may be specifically associated with loss of chromosomes 1 and Y. Because this is a small series, further investigation may help establish whether cytogenetic studies can provide diagnostic and pathogenic information about renal oncocytomas.

Adventitial gene transfer of recombinant endothelial nitric oxide synthase to rabbit carotid arteries alters vascular reactivity

BACKGROUND Adventitial gene transfer may serve as a tool to study vascular biology and may have therapeutic potential. We investigated the hypothesis that adenovirus-mediated transfer of the gene for endothelial nitric oxide synthase (eNOS) to the adventitia would alter vascular reactivity. METHODS AND RESULTS Rabbit carotid arteries were surgically isolated and adenoviral vectors encoding eNOS (AdeNOS) or beta-galactosidase instilled into the periarterial sheath at a concentration of 1 x 10(10) pfu/mL. Arteries were harvested 4 days later for immunostaining, NOS enzymatic assay, measurement of cGMP, and vasomotor studies. Transgene expression in the adventitia was confirmed by histochemistry for beta-galactosidase and immunostaining for eNOS with a monoclonal antibody. Calcium-dependent NOS enzymatic activity and cGMP levels were significantly greater in the AdeNOS-transduced arteries. Maximal contractions to phenylephrine (10(-5) mol/L) were diminished in the AdeNOS-transduced arteries (4.6+/-0.2 versus 5.6+/-0.2 g; P<.05), but in the presence of the eNOS inhibitor N(G)-monomethyl-L-argininc (3x10(-4) mol/L) there was no difference between the two groups (7.1+/-0.2 versus 7.5+/-0.3 g; P=NS). Relaxations to calcium ionophore obtained during submaximal contractions to phenylephrine were significantly enhanced in the AdeNOS-transduced arteries (-log EC50, 7.77+/-0.08 versus 7.45+/-0.07; P<.02). CONCLUSIONS We conclude that eNOS gene transfer to the adventitia alters vascular reactivity, as demonstrated by diminished contractile responses to phenylephrine and enhanced relaxations to calcium ionophore. This may represent a therapeutic strategy for vascular diseases characterized by decreased bioavailability of NO.

Localized malignant mesothelioma: A clinicopathologic and flow cytometric study

Six examples of malignant mesothelioma appearing as a localized pleural mass are described. There were four women and two men, ranging in age from 42 to 76 years. A history of asbestos exposure was obtained from three patients. The tumors ranged in size from 2.8 to 10 cm. Two were pedunculated and four were sessile with broad-based pleural attachments. Histologically, three tumors were purely epithelioid and three were biphasic. Immunohistochemical stains in all six cases were positive for cytokeratin and negative for carcinoembryonic antigen. Five were also positive for epithelial membrane antigen. Five were negative for Leu-M1, while one showed focal staining in a peripheral membrane pattern. Electron microscopy in two purely epithelioid tumors showed long, thin microvilli, well-developed desmosomes, and numerous tonofilaments. Flow cytometry showed an aneuploid DNA content in four tumors and a diploid content in one. Flow cytometry in five cases identified a DNA aneuploid cell population in four tumors and a diploid population in one. Three patients showed signs of local recurrences 4, 7, and 18 months after excision and died of their disease 12, 10, and 24 months after diagnosis, respectively. Three patients are well with no evidence of disease 8, 24, and 96 months after diagnosis. These findings indicate that malignant mesotheliomas of the pleura may rarely appear as a localized mass. The biologic behavior of such tumors is difficult to predict, but some patients survive disease-free for a long time after surgical excision.

Multiple endocrine neoplasia type 2B: More than an endocrine disorder*

BACKGROUND Multiple endocrine neoplasia type 2B (MEN 2B) is a rare disorder differentiated from MEN 2A primarily by its extraendocrine features. This report describes the clinical spectrum and outcome of MEN 2B. METHODS Twenty-one patients underwent operation for manifestations of MEN 2B between 1970 and 1993. Median follow-up was 16.9 years. Diagnosis was made through family screening in nine, the development of medullary thyroid carcinoma (MTC) in seven, phenotypic features in four, and constipation in one. Median age at presentation of colonic dysfunction, MTC, and pheochromocytoma was 0.1, 16, and 28 years, respectively. RESULTS Every patient had MTC. Fifteen (94%) of 16 patients undergoing primary thyroidectomies had multicentric disease, and seven (44%) had nodal metastases. Seven patients (33%) had pheochromocytoma, six bilateral and one malignant. Adrenalectomy was curative in every patient. Nineteen patients (90%) had colonic disturbances, typically chronic constipation from birth. Megacolon developed in 14 patients, and eight required colonic surgery. Every patient had the characteristic phenotype. Dominant features included neuromas of the tongue, buccal mucosa, lips, conjunctivae, and eyelids and a marfanoid habitus. Other features included high arched palate, corneal nerve thickening, and dental and skeletal abnormalities. Four patients died, two of metastatic MTC, one after operation for metastatic MTC, and one as a consequence of colonic perforation. Of 17 survivors, three have hepatic metastases from MTC, eight have nodal metastases, and six are well with normal or mildly elevated calcitonin levels. CONCLUSIONS MEN 2B is characterized by a relatively aggressive form of MTC, bilateral pheochromocytoma, severe colonic dysfunction, and a multitude of other extraendocrine abnormalities. Early recognition of MEN 2B and early prophylactic thyroidectomy are essential. Colonic dysfunction has previously received little attention, and further investigation of the pathogenesis and treatment of this disorder is warranted.

Adventitial Expression of Recombinant eNOS Gene Restores NO Production in Arteries Without Endothelium

The current study was designed to determine the effect of recombinant endothelial nitric oxide synthase (eNOS) gene expression on endothelium-dependent relaxations to bradykinin in isolated canine basilar, coronary, or femoral arteries. Arterial rings were exposed ex vivo (30 minutes at 37 degrees C) to an adenoviral vector encoding either the eNOS gene (AdCMVeNOS) or the beta-galactosidase reporter gene (AdCMVbeta-Gal). Twenty-four hours after transduction, transgene expression was evident mainly in the adventitia. Expression of recombinant proteins was much higher in basilar arteries than in coronary or femoral arteries. Rings of control, AdCMVbeta-Gal, and AdCMVeNOS arteries with and without endothelium were suspended for isometric tension recording. Levels of cGMP were measured by radioimmunoassay. In AdCMVeNOS basilar arteries with endothelium, relaxations to low concentrations of bradykinin (3 x 10(-11) to 10(-9) mol/L) were significantly augmented. In contrast, in coronary and femoral arteries with endothelium, AdCMVeNOS transduction did not affect relaxations to bradykinin. Removal of the endothelium abolished bradykinin-induced relaxations in control and AdCMVbeta-Gal basilar arteries. However, in basilar arteries transduced with AdCMVeNOS even when the endothelium was removed, stimulation with bradykinin (3 x 10(-11) to 10(-9) mol/L) caused relaxations as well as increases in cGMP production. The relaxations to bradykinin were completely blocked by an NOS inhibitor, NG-nitro-L-arginine methyl ester. Electron microscopic analysis revealed that recombinant eNOS protein was expressed in fibroblasts of the basilar artery adventitia. These results suggest that genetically modified adventitial fibroblasts may restore production of NO in cerebral arteries without endothelium. Our findings support a novel concept in vascular biology that fibroblasts in the adventitia may play a role in the regulation of vascular tone after successful transfer and expression of recombinant eNOS gene.

Amyloidosis and endomyocardial biopsy: Correlation of extent and pattern of deposition with amyloid immunophenotype in 100 cases

The heart is subject to involvement by primary (AL), senile (AS), and familial (AF) forms of amyloidosis, but the frequency, severity, and therapy of amyloid-related cardiac symptoms differ depending on the type of amyloidosis present. Endomycardial biopsy is a safe and reliable procedure for diagnosing cardiac amyloidosis, and immunohistochemical staining of routinely processed biopsy specimens can be performed to classify the type of amyloid present. However, whether or not the type can be determined from the histologic extent and pattern of amyloid deposition is unclear. Endomyocardial biopsy specimens from 100 patients with cardiac amyloidosis (74 AL, 22 AS, 4 AF) were examined, and the histologic extent and pattern of amyloid deposition were correlated with the amyloid immunophenotype. No difference in the extent of amyloid deposition was identified among the three types. Interstitial nodules of amyloid were more common in AS (82%) than in AL (50%, p = 0.0129), whereas vascular involvement was more frequently observed in AL (88%) than in AS (26%, p < 0.0001). Endocardial and interstitial pericellular deposition occurred with similar frequencies in both groups. Although statistically significant differences existed in the patterns of amyloid deposition, they did not allow reliable distinction between the different types in individual cases. Consequently, in older patients without serum or urinary light chains, immunohistochemical staining is recommended to distinguish AL from AS types of amyloid in cardiac biopsy tissues.

Ductal Carcinoma in Situ of the Breast

Ductal carcinoma in situ (DCIS) of the breast is a complex pathologic condition in which malignant breast epithelial cells arise and proliferate in the ducts but do not invade the surrounding stroma. As options for the primary treatment of invasive breast cancer have broadened to include breast-conserving therapy, continued use of mastectomy as standard care for DCIS has been questioned [1]. The increasing incidence of DCIS, its biological heterogeneity, and controversy about its treatment have made the management of this condition challenging. We review data on the natural history of this disorder and the results obtained with various management approaches. Specifically, we address the following points: the incidence of DCIS, the classification of the condition, the molecular genetic abnormalities associated with it, its usual clinical presentation, its natural history, the proportion of lesions that are multicentric, the treatment options, whether axillary lymph node dissection should be performed, whether all patients need radiotherapy if they undergo lumpectomy, the survival rates associated with these treatments, the risk factors for recurrence, the best treatment for recurrence, and the possible role of hormonal therapy. Methods We performed a computerized search of the MEDLINE database for English-language articles on DCIS of the breast published since 1966. The search was done by using the words carcinoma in situ, ductal carcinoma in situ, intraductal breast cancer, and DCIS. References in the identified articles were reviewed. Because randomized trials were given higher value but were relatively scarce, retrospective studies were also reviewed. In addition, published abstracts were reviewed, but no personal communications and case reports were considered. The authors reviewed all sources critically but conducted no formal statistical analyses. Data Synthesis Biology and Natural History Incidence The exact incidence of DCIS in the general population is unknown and has been a source of controversy. In an autopsy study of 519 women of various ethnic backgrounds, only one case (0.2%) of DCIS was found (in a woman who died at 40 years of age) [2]. Of these 519 women, only 117 were older than 55 years of age. Alpers and Wellings [3] performed autopsies on 185 patients, of whom 9 (4.9%; 11 breasts) had evidence of the tumor on subgross sampling (which involves cutting breast tissue into 2-mm slices, examining the slices with a dissecting microscope, and evaluating any focal lesion [4]). The findings of the autopsy studies suggest that incidental DCIS of uncertain clinical relevance is not common. Variations in incidence among autopsy studies probably reflect differences in sampling techniques and diagnostic criteria. Ductal carcinoma in situ of the breast also occurs in men and represents 3.5% to 7% of all cases of male breast cancer [5, 6]. The incidence of DCIS has increased in recent years, partly because screening mammography is more refined and more widely used [7-10]. In 1992, DCIS was diagnosed in more than 23 300 women (age-adjusted incidence rate, 15.9 per 100 000 women) [11]. The rate of increase in incidence has been higher for DCIS than for any other type of breast cancer [12]. The reported incidence in women 50 years of age or older increased 235% from 1979 to 1986; in contrast, the incidence of invasive cancer increased 50% [13]. However, mammography alone does not seem to explain the increasing incidence of DCIS. Data from the metropolitan Atlanta Surveillance, Epidemiology, and End Results (SEER) study (1979 to 1986) showed that asymptomatic tumors (those detected on screening mammography alone) accounted for only 25% to 40% of the increase in incidence [14]. These reports suggest that increased detection accounts for some but not all of the increase in incidence. The National Cancer Institute SEER data for the entire United States confirmed this trend [11]. Overall, the total number of cases of DCIS in 1992 was 200% greater (23 368 cases) than expected for that year as calculated from the trends between 1973 and 1983. Pathology Ductal carcinoma in situ is a heterogeneous entity with several morphologic variants that markedly differ in gross appearance, growth pattern, and cytologic features. Furthermore, it is part of a spectrum of proliferative ductal lesions of the breast that extends from epithelial hyperplasia without atypia to microinvasive carcinoma. Various classification schemes for DCIS exist. Most pathologists and clinicians recognize two major subtypes of DCIS according to the presence or absence of comedo necrosis, but this is a matter of considerable debate. These two subtypes differ not only in pathologic features but also in clinical presentation, appearance on mammography, and malignant potential. The comedo necrosis type of DCIS is diagnosed when at least one duct in the breast is filled and expanded by large, markedly atypical cells and has abundant central luminal necrosis (Figure 1). This necrotic material is usually partially calcified and thus may be recognized on mammography as linear and branching calcifications. Prominent periductal fibrosis is common and may render the lesion clinically palpable. The resulting distortion of the breast parenchyma may present the pathologist with the difficult and sometimes impossible task of excluding stromal invasion. Figure 1. Comedo necrosis ductal carcinoma in situ. All other forms of DCIS are of the noncomedo necrosis type and include the cribriform, micropapillary, and solid types (Figure 2). Many examples of the noncomedo necrosis type consist of a combination of the various histologic patterns. Although necrosis may be present, it is less prominent than in the comedo necrosis type and is not as prone to calcification. Just as the comedo necrosis type may overlap with microinvasive carcinoma, distinguishing small examples of the noncomedo necrosis type from atypical ductal hyperplasia may be difficult. However, if careful attention is paid to standardized diagnostic criteria, this distinction can be made with reasonable certainty [15-17]. Figure 2. Noncomedo necrosis ductal carcinoma in situ. Many pathologists think that the comedo necrosis-noncomedo necrosis classification scheme is too simplistic and does not account for the marked heterogeneity of DCIS. This has led to several new classification schemes for DCIS [18-21]. All of these schemes take into account some or all of the following features: nuclear grade, amount and type of necrosis, growth pattern, tumor size, and architectural differentiation. The optimal classification scheme remains controversial. Molecular Genetics and Cytogenetic Studies Little information is available on chromosomal abnormalities in DCIS [22]. With the use of interphase cytogenetic techniques, 18 of 21 (86%) samples of the tumor were aneusomic for chromosome 1 [23]. In another study, aneuploidy, as determined by image analysis, was seen in 77.5% of cases of the tumor, mainly in the high- and intermediate-grade subtypes [24]. Specimens of DCIS have several alterations at the molecular genetic level. Overexpression of c-erbB-2 occurs in 46% to 60% of cases; the frequency is higher with the comedo necrosis type. In contrast, this overexpression is seen in only 20% to 25% of cases of invasive breast cancer [25-30]. At least some cases of invasive breast cancer that express c-erbB-2 seem to be derived from preexisting DCIS [31]. Maguire and colleagues [31] studied 12 specimens containing the noncomedo necrosis type and derivative invasive adenocarcinomas in the same section, all of which were negative for c-erbB-2 expression. However, of 13 comedo necrosis carcinomas in situ with an invasive component, 10 had definite c-erbB-2 expression that was similar in the in situ and invasive components in every case. Mutations of the p53 gene are present in DCIS and are more common in the comedo necrosis type [32]. Allelic imbalance (loss of intensity of one allele) for the BRCA1 gene has been found in 74% of cases of the tumor [33]. Loss of heterozygosity has been described in the tumor at loci reported to show allelic loss in invasive breast cancers [34]. Identical loss of heterozygosity in the in situ component of tumors with invasive tumor cells has been reported on chromosome 11q13 [35], further supporting the idea that the tumor is preinvasive. Over-expression of cyclin D1, an oncogene on 11q13, is present in nearly 90% of malignant breast lesions (both DCIS and invasive breast cancer) [36]. Although some molecular genetic data support the hypothesis that invasive breast cancer can arise from preexisting in situ lesions, this has not been definitively proven. More work is needed to broaden our understanding of the relation between DCIS and invasive breast cancer. Clinical Presentation Ductal carcinoma in situ can present clinically as a palpable mass; Paget disease (which may be diagnosed independently); nipple discharge; or, most commonly, a nonpalpable abnormality on mammography [37]. It now accounts for 20% to 30% of all newly diagnosed cases of breast cancer in medical centers where screening is standard [38]. The most frequent radiologic finding is a collection of malignant-appearing or indeterminate calcifications [39], often with no other associated abnormalities. In our experience with nonpalpable lesions seen on mammography, 22% of indeterminate calcifications alone are associated with a histologic diagnosis of malignancy; 76% of these are minimal cancers, and almost all are DCIS [40]. Of all malignant-appearing calcifications, 92% are associated with a malignant histologic diagnosis. Fifty-eight percent of these are minimal cancers, and most are DCIS [40]. In addition, atypical features may include circumscribed nodules, ill-defined masses, ductal asymmetry, architectural distortion, and negative findings on mammography [41]. In a review of 100 mammographically detected cases of DCIS, 72% pr