Effects of fasting and glucocorticoids on hepatic gluconeogenesis assessed using two independent methods in vivo

The purpose of this study was to compare the assessment of gluconeogenesis (GNG) in the overnight- and prolonged-fasted states and during chronic hypercortisolemia using the arteriovenous difference and [14C]phosphoenolpyruvate-liver biopsy techniques as well as a combination of the two. Two weeks before a study, catheters and flow probes were implanted in the hepatic and portal veins and femoral artery of dogs. Animals were studied after an 18-h fast (n = 8), a 42- or 66-h fast (n = 7), and an 18-h fast plus a continuous infusion of cortisol (3.0 microg. kg(-1). min(-1)) for 72 h (n = 7). Each experiment consisted of an 80-min tracer ([3-(3)H]glucose and [U-(14)C]alanine) and dye equilibration period (-80 to 0 min) and a 45-min sampling period. In the cortisol-treated group, plasma cortisol increased fivefold. In the overnight-fasted group, total GNG flux rate (GNG(flux)), conversion of glucose 6-phosphate to glucose (GNG(G-6-P-->Glc)), glucose cycling, and maximal GNG flux rate (GNG(max)) were 0.95 +/- 0.14, 0.65 +/- 0.06, 0.62 +/- 0.06, and 0.70 +/- 0.09 mg. kg(-1). min(-1), respectively. In the prolonged-fasted group, they were 1.50 +/- 0.18, 1.18 +/- 0.13, 0.40 +/- 0.07, and 1.28 +/- 0.10 mg. kg(-1). min(-1), whereas in the cortisol-treated group they were 1.64 +/- 0.33, 0.99 +/- 0.29, 1.32 +/- 0.24, and 0.91 +/- 0.13 mg. kg(-1). min(-1). These results demonstrate that GNG(G-6-P-->Glc) and GNG(max) were almost identical. However, these rates were 15-38% lower than GNG(flux) generated by a combination of the two methods. This difference was most apparent in the steroid-treated group, where the combination of the two methods (GNG(flux)) detected a significant increase in gluconeogenic flux.

Implications of follicular neoplasms, atypia, and lesions suspicious for malignancy diagnosed by fine-needle aspiration of thyroid nodules

OBJECTIVE

To break out subcategories of atypical and suspicious cytologic interpretations of thyroid aspirations and correlate those with final histologic diagnosis.

SUMMARY BACKGROUND DATA

Fine-needle aspiration (FNA) of thyroid nodules has become the primary diagnostic tool in the initial evaluation of thyroid nodules. Management of thyroid nodules is based on statistical data correlating a specific cytologic reading with the probability of malignancy. Two particular cytologic readings that frustrate both cytopathologists and surgeons are follicular neoplasms and cells that show atypia. In most reported series, follicular neoplasms and cells showing atypia are included in a broad "suspicious" category, with reported overall malignancy rates generally between 20% and 30%. However, there is interest in determining whether these suspicious lesions can be subcategorized, allowing a more accurate assessment of the risk of malignancy. In addition, there is recent evidence that the incidence of follicular cancer may be declining in this country, possibly decreasing the probability that a "follicular neoplasm" will prove to be a follicular cancer.

METHODS

From January 1994 through December 2000, 709 thyroid FNAs were performed at a single institution. Those interpreted as suspicious and the subsequent histologic reports were reviewed. From this set, four specific categories were defined, and the clinical records for patients whose cytology matched these categories form the subject of this study. These four categories are follicular neoplasms without atypia, follicular neoplasms with atypia, atypia, and suspicious for malignancy. In addition, lesions with nondiagnostic cytology were reviewed. Only lesions for which there was histologic follow-up were considered.

RESULTS

Ninety-eight aspirates were categorized as follicular neoplasms without atypia, follicular neoplasms with atypia, or atypia alone. Of 74 follicular neoplasms without atypia, only 5 (6.8%) were malignant, and none of these were follicular thyroid cancers. Nine of the lesions were follicular neoplasms with atypia, and four (44.4%) of these were malignant, including two that were invasive follicular cancers. Of 15 lesions showing atypia alone, 3 (20%) were malignant, all of which were papillary thyroid cancers. Twenty-five additional patients had lesions highly suspicious for malignancy. Twenty-one (84%) of these lesions were malignant, the majority being papillary thyroid cancers. Only one was a follicular cancer. Fifty patients with nondiagnostic cytology had subsequent action taken. Thirty-one of these lesions were resected, with five (16.1%) proving to be malignant.

CONCLUSIONS

Thyroid nodules whose FNA is diagnosed as highly suspicious for malignancy should be resected unless there are significant contraindications to a surgical procedure. The extremely low rate (2%) of invasive follicular cancers among all follicular neoplasms may reflect changing histologic criteria for follicular carcinoma, a true change in the disease frequency, or both. For thyroid nodules whose cytology shows a follicular neoplasm without atypia, malignancy rates of 8% or less may allow nonsurgical options, including reevaluation in selected populations. Continued efforts to correlate malignancy rates to specific cytologic criteria will allow patients to make more informed decisions regarding their medical care.

Dirofilaria repens infection in a dog: diagnosis and treatment with melarsomine and doramectin

Therapy of canine dirofilariois due to Dirofilaria repens is indicated for dogs suffering from clinical signs of this disease, such as dermal swelling, sub-cutaneous nodules and pruritus. It is also important in order to decrease the risk of infection to other dogs and humans in the vicinity of the infected animal when suitable mosquito vectors are present. Combined therapy with the arsenic adulticide melarsomine and the avermectin microfilaricidal doramectin was effective in clearing infection with D. repens in a dog. The number of microfilariae dropped from 17 microl(-1) blood pre-treatment to 7 microl(-1) following the first adulticide injection and reached 0 a day after the microfilaricidal administration. The dog remained negative for D. repens microfilaremia during a follow-up period of 90 days. Euthanasia and necropsy performed 3 months after the initiation of therapy due to a progressive neoplastic disease revealed no evidence of filariae.

Effects of cyclosporine A and prednisone treatment on mixed meal disposition in dogs with hepatic denervation

BACKGROUND

Compared with untreated dogs, normal dogs treated for 7 days with cyclosporine A and prednisone exhibited a 25% reduction in the absorption of glucose from a mixed meal and a 4- to 5-fold increase in net hepatic glucose uptake, without reduction of postprandial glycemia. The hepatic nerves are also involved in directing postprandial glucose disposition. Therefore, we hypothesized that the combination of immunosuppressive therapy and hepatic denervation would create additional alterations in the disposition of glucose from a mixed meal.

METHODS

Six 24-hour-fasted conscious dogs that had undergone surgical hepatic denervation (DN) and received cyclosporine A 15 mg/kg daily and prednisone 5 mg twice daily for 7 consecutive days before study (DN + CyP group) received an intragastric mixed-meal feeding over 30 minutes. The results were compared with those from a group of 8 normally innervated dogs receiving the same immunosuppressives (CyP group).

RESULTS

Arterial blood glucose concentrations remained elevated over basal in both groups at the end of the 480 minutes postprandial period. The arterial plasma insulin response was no different in the 2 groups (area under the curve 119+/-25 and 100+/-40 nmol/L in DN + CyP and CyP, respectively). In both groups, net gut glucose output was equivalent to approximately 45% of the glucose in the meal, and net hepatic glucose uptake accounted for approximately 54% to 66% of the absorbed glucose. Arterial blood lactate concentrations and net hepatic lactate output were not different between groups at any time.

CONCLUSIONS

Immunosuppressive therapy is responsible for most of the alterations in postprandial carbohydrate metabolism observed in this model; the lack of hepatic nerves has little additional impact.

Resetting wave forms in dictyostelium territories

The mechanism by which spiral wave patterns appear in populations of Dictyostelium was probed experimentally by external chemical perturbation. Spiral waves, which often arise from the breakup of circular waves driven by pacemakers, typically entrain those pacemakers. We studied these processes by resetting the waves with a spatially uniform pulse of extrinsic cyclic AMP. A pattern of spirals reappeared if resetting was early in the signaling stage, but only targets emerged following late resetting, in a manner analogous to cardiac defibrillation. This supports recent hypotheses that wave pattern selection naturally occurs by slow temporal variation of the excitability of the cells.

Computer imaging versus conventional esthetic consultation: a prospective clinical study

Computer imaging can be helpful in demonstrating to patients the potential outcome of esthetic dental procedures. The current clinical study assesses the effectiveness of computer imaging by comparing the reactions of patient and dentist to conventional consultations versus the use of computer imaging. The responses from 35 subjects show that computer imaging consultations are more effective in helping patients decide to accept treatment. Patient satisfaction was higher (93.75%) with computer consultations than with conventional methods (83.3%). Computer imaging consultations were easier to conduct but significantly (p < .05) more time consuming.

Use of percutaneous ethanol injection for treatment of bilateral hyperplastic thyroid nodules in cats

OBJECTIVE

To determine the efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of hyperthyroidism caused by bilateral hyperplastic thyroid nodules in cats. DESIGN; Prospective study.

ANIMALS

7 cats.

PROCEDURE

Hyperthyroidism was diagnosed on the basis of clinical signs and increased serum total thyroxine (TT4) concentrations. The presence of 2 cervical thyroid nodules was confirmed by use of ultrasonography and technetium Tc 99m albumin thyroid scans. After the death of 1 cat that received PEI in both thyroid nodules at the same time, the protocol was changed to injecting ethanol into 1 nodule at a time, with at least 1 month between injections. Clinical signs, serum TT4 concentrations, serum ionized calcium concentrations, laryngeal function, findings on ultrasonographic examinations of the ventral cervical region, and results of thyroid scans were monitored.

RESULTS

Serum TT4 concentrations transiently decreased in all 6 cats (into the reference range in 5 of 6 cats) within 4 days of the first staged ethanol injection. Each subsequent injection resulted in a transient decrease in serum TT4 concentration. The longest period of euthyroidism was 27 weeks. Adverse effects included Horner's syndrome, dysphonia, and laryngeal paralysis. One cat died of unrelated causes. One cat underwent bilateral thyroidectomy, 2 cats were treated with methimazole, and 2 cats that had increased serum TT4 concentrations were not treated further, because they remained clinically normal.

CONCLUSIONS AND CLINICAL RELEVANCE

Percutaneous ethanol ablation of bilateral thyroid nodules as a treatment for cats with hyperthyroidism is not recommended. This treatment is not as efficacious as the medical and surgical treatments presently used.

Intraoral camera helps predict and prevent tooth loss

The video exam has proven to be a most effective means of re-establishing trust between patient and dentist by making the patient a co-diagnostician. In fact, it is not uncommon for patients to stop the diagnosis and ask specific questions about what they see. They can begin to diagnose pathology even before the dentist mentions it. A major benefit to the dentist is that invariably the exam reveals conditions not seen with typical clinical exams even using magnification loops. Although the intraoral camera has been around for more than a decade, its benefit during the video exam is more important now than ever before (8, 9). Every new patient and all patients of record should have the benefit of a video exam, as well as the dentist.

Twenty-Five-Year Surgical Experience with Pheochromocytoma in Children

Our objective was to analyze the presentation, diagnostic localization, operative management, histology, and long-term outcome of a single center's experience with pheochromocytomas in children. A chart review was done to identify all operatively managed pheochromocytomas in patients age 18 years or younger. Open and laparoscopic cases were included. We reviewed the presentation, diagnostic imaging, localization, operative management, pathology, and postoperative outcome of these patients. Clinic visits, contact with the tumor registry, and telephone interviews were used for follow-up. From 1973 through 1999, there were 11 children (four males and seven females) with 14 pheochromocytomas. Two (18.2%) patients had bilateral adrenal lesions and one patient had both adrenal and extra-adrenal tumors. Six (54.5%) patients had extra-adrenal lesions. The average age at operation was 14.7 years (range 9–18 years). Nine (82%) patients had significant hypertension at presentation. CT was used to localize the tumor in eight patients and urine catecholamine levels were used to confirm the diagnosis. Two of the cases were associated with inherited syndromes (multiple endocrine neoplasia 2A and von Hippel-Lindau). Ten patients underwent an open operation and one patient had a laparoscopic resection. The average patient follow-up was 9.2 years (range 9 months to 25 years). There were no operative complications and all patients were alive and well at the time of last follow-up. Three patients (27.2%) had tumors with microscopic malignant features. No tumors recurred or had evidence for metastatic spread. We conclude that peak incidence of pheochromocytomas in children is in early adolescence. Resection can be carried out safely with minimal morbidity and mortality. Current best management of this entity includes establishment of a biochemical diagnosis, adequate preoperative blockade, appropriate imaging, and an individualized operative approach based on tumor location and size.

Twenty-five-year surgical experience with pheochromocytoma in children

Our objective was to analyze the presentation, diagnostic localization, operative management, histology, and long-term outcome of a single center's experience with pheochromocytomas in children. A chart review was done to identify all operatively managed pheochromocytomas in patients age 18 years or younger. Open and laparoscopic cases were included. We reviewed the presentation, diagnostic imaging, localization, operative management, pathology, and postoperative outcome of these patients. Clinic visits, contact with the tumor registry, and telephone interviews were used for follow-up. From 1973 through 1999, there were 11 children (four males and seven females) with 14 pheochromocytomas. Two (18.2%) patients had bilateral adrenal lesions and one patient had both adrenal and extra-adrenal tumors. Six (54.5%) patients had extra-adrenal lesions. The average age at operation was 14.7 years (range 9-18 years). Nine (82%) patients had significant hypertension at presentation. CT was used to localize the tumor in eight patients and urine catecholamine levels were used to confirm the diagnosis. Two of the cases were associated with inherited syndromes (multiple endocrine neoplasia 2A and von Hippel-Lindau). Ten patients underwent an open operation and one patient had a laparoscopic resection. The average patient follow-up was 9.2 years (range 9 months to 25 years). There were no operative complications and all patients were alive and well at the time of last follow-up. Three patients (27.2%) had tumors with microscopic malignant features. No tumors recurred or had evidence for metastatic spread. We conclude that peak incidence of pheochromocytomas in children is in early adolescence. Resection can be carried out safely with minimal morbidity and mortality. Current best management of this entity includes establishment of a biochemical diagnosis, adequate preoperative blockade, appropriate imaging, and an individualized operative approach based on tumor location and size.

Disposition of a mixed meal by conscious dogs after seven days of treatment with cyclosporine A and prednisone

BACKGROUND

Combination immunosuppressive therapy, that often includes prednisone and cyclosporine A (CyA), is commonly used in the treatment of organ transplant patients. We hypothesized that CyA and prednisone treatment would alter the roles of the liver and peripheral tissues in the disposal of carbohydrates from a meal.

METHODS

Using the arteriovenous difference technique, we examined the disposition of an intragastrically delivered mixed meal in eight 24-hour fasted conscious dogs that had received CyA 15 mg x kg(-1) daily and prednisone 5 mg twice daily for 7 consecutive days before study (CyA-prednisone group). The results were compared with those from a group of 13 dogs (control group) receiving the same meal but no drugs.

RESULTS

Neither arterial blood glucose concentrations nor arterial plasma insulin or glucagon concentrations differed significantly between the groups at any time. Cumulative net gut glucose output was equivalent to 43 +/- 9 vs 57% +/- 7% of the glucose in the meal in CyA-prednisone vs control (p = .12). The CyA-prednisone group exhibited greater (p < .05) mean net hepatic glucose uptakes (15.4 +/- 4.6 vs 4.3 +/- 2.2 micromol x kg(-1) x min(-1) and net hepatic fractional extractions of glucose (7.8 +/- 1.6 and 1.5% +/- 1.0%) than the control group. Arterial blood lactate concentrations and net hepatic lactate output were greater in the CyA-prednisone group than the control group (p < .05). Hepatic glycogen content at the end of the study was 2.5-fold greater in the CyA-prednisone group than in the control group (p < .05). The nonhepatic tissues disposed of approximately 91% of the absorbed glucose in the control group but only approximately 26% in the CyA-prednisone group (p < .05).

CONCLUSIONS

CyA-prednisone treatment caused a marked shift in the carbohydrate disposal from a meal, enhancing the hepatic glucose uptake and decreasing peripheral glucose disposal.

Phospholipase C and termination of G-protein-mediated signalling in vivo

In Drosophila photoreceptors, phospholipase C (PLC) and other signalling components form multiprotein structures through the PDZ scaffold protein INAD. Association between PLC and INAD is important for termination of responses to light; the underlying mechanism is, however, unclear. Here we report that the maintenance of large amounts of PLC in the signalling membranes by association with INAD facilitates response termination, and show that PLC functions as a GTPase-activating protein (GAP). The inactivation of the G protein by its target, the PLC, is crucial for reliable production of single-photon responses and for the high temporal and intensity resolution of the response to light.

Effect of minimally invasive radioguided parathyroidectomy on efficacy, length of stay, and costs in the management of primary hyperparathyroidism

OBJECTIVE

To compare the first 20 patients who underwent minimally invasive radioguided parathyroidectomies (MIRPs) performed at the authors' institution with 20 similar patients who underwent a more conventional surgical approach for primary hyperparathyroidism.

SUMMARY BACKGROUND DATA

The technique of parathyroidectomy has traditionally involved a bilateral exploration of the neck with the intent of visualizing four parathyroid glands and resecting enlarged parathyroid glands. Parathyroid scanning using radioisotopes has evolved and now can localize adenomas in 80% to 90% of patients. MIRP combines parathyroid scanning with a hand-held intraoperative detector that guides the surgeon to the adenoma.

METHODS

Forty patients with documented primary hyperparathyroidism who underwent surgery by a single surgeon between January 1998 and May 1999 were included in this study. Twenty of these patients underwent MIRP. The technique involved injecting 20 mCi technetium-99m sestamibi 2 hours before surgery and performing a parathyroid scan. If the scan was considered positive for a single adenoma, patients were taken to the operating room and given the choice of either general anesthesia or intravenous sedation with local anesthesia. Using an incision of 4 cm or less, the dissection down to the adenoma was guided by the Navigator miniature hand-held probe. An additional 20 patients who underwent more conventional bilateral or unilateral neck exploration were chosen to match the MIRP patient population. Both groups included four patients undergoing repeat surgery for persistent or recurrent primary hyperparathyroidism and one patient with multiple endocrine neoplasia type 1 syndrome. Patient demographics, preoperative calcium and parathyroid hormone levels, operative time, total time in the operating room, time in the recovery room, complications, hospital charges for the operating room, and total hospital charges were analyzed.

RESULTS

There were no differences in patient demographics, presenting symptoms, or preoperative calcium level between patients undergoing the standard procedure versus MIRP. Operative time, total time in the operating room, operative charges, and total hospital charges were significantly reduced in the MIRP group. All 40 patients were cured of primary hyperparathyroidism. There were no recurrent laryngeal nerve injures in either group. The mean length of stay in the standard group was 1. 35 days; in the MIRP group, 65% of patients were discharged within 5 hours after surgery.

CONCLUSIONS

The MIRP technique resulted in excellent cure rates for primary hyperparathyroidism while simultaneously decreasing operative time and hospital stays. These resulted in significant cost reductions without compromising patient safety. The technique may significantly change the management of primary hyperparathyroidism.

Bistable helices

We extend elasticity theory of filaments to encompass systems, such as bacterial flagella, that display competition between two helical structures of opposite chirality. A general, fully intrinsic formulation of the dynamics of bend and twist degrees of freedom is developed using the natural frame of space curves, spanning from the inviscid limit to the viscously overdamped regime applicable to cellular biology. Aspects of front propagation found in flagella are discussed.

Chiral self-propulsion of growing bacterial macrofibers on a solid surface

Supercoiling motions that accompany the growth of bacterial macrofibers (multicellular filamentous structures formed in B. subtilis by cell division without separation) are responsible for rolling, pivoting, and walking of fibers on a surface. Fibers possess a fulcrum about which they pivot and step in a chiral manner; forces and torques associated with cell growth, when blocked by friction, result in self-propulsion. The elastic engine that drives macrofiber motions generates torques estimated as microdyn cm and femtowatts of power; optical trapping studies yield a first direct measurement of the Young's modulus of the bacterial cell wall, the engine's "working fluid," of ca. 0.05 GPa.

Twirling and whirling: viscous dynamics of rotating elastic filaments

Motivated by diverse phenomena in cellular biophysics, including bacterial flagellar motion and DNA transcription and replication, we study the overdamped nonlinear dynamics of a rotationally forced filament with twist and bend elasticity. Competition between twist injection, twist diffusion, and writhing instabilities is described by coupled PDEs for twist and bend evolution. Analytical and numerical methods elucidate the twist/bend coupling and reveal two regimes separated by a Hopf bifurcation: (i) diffusion-dominated axial rotation, or twirling, and (ii) steady-state crankshafting motion, or whirling. The consequences of these phenomena for self-propulsion are investigated, and experimental tests proposed.

Huckebein repressor activity in Drosophila terminal patterning is mediated by Groucho

The Groucho corepressor mediates negative transcriptional regulation in association with various DNA-binding proteins in diverse developmental contexts. We have previously implicated Groucho in Drosophila embryonic terminal patterning, showing that it is required to confine tailless and huckebein terminal gap gene expression to the pole regions of the embryo. Here we reveal an additional requirement for Groucho in this developmental process by establishing that Groucho mediates repressor activity of the Huckebein protein. Putative Huckebein target genes are derepressed in embryos lacking maternal groucho activity and biochemical experiments demonstrate that Huckebein physically interacts with Groucho. Using an in vivo repression assay, we identify a functional repressor domain in Huckebein that contains an FRPW tetrapeptide, similar to the WRPW Groucho-recruitment domain found in Hairy-related repressor proteins. Mutations in Huckebein's FRPW motif abolish Groucho binding and in vivo repression activity, indicating that binding of Groucho through the FRPW motif is required for the repressor function of Huckebein. Taken together with our earlier results, these findings show that Groucho-repression regulates sequential aspects of terminal patterning in Drosophila.

Laparoscopic left adrenalectomy for pheochromocytoma in a child

Although uncommon, adrenalectomy occasionally is indicated in children. To date, this procedure has required either a laparotomy or a flank incision. The authors report the case of a child with episodic palpitations, diaphoresis, chest discomfort, and occipital headache who underwent laparoscopic adrenalectomy for pheochromocytoma without complication.

The current status of vital tooth whitening techniques

Tooth whitening of vital teeth continues to have a major impact on the practice of dentistry. The growing public interest in having whiter, brighter teeth is clearly evident in the advertisements from toothpaste manufacturers on "whitening" formulations of their products and by the number of individuals seeking whitening procedures from their dentists. In addition, new over-the-counter whitening products continue to emerge in a marketplace that cannot seem to get teeth white enough, bright enough, fast enough. What new products and procedures have evolved over the past decade to whiten teeth? Are they better, safer, faster, and more effective now? Are dentists meeting public demand for whiter teeth and is this quest having a positive or negative impact on the practice of dentistry or the patient's dental health? I posed these questions to a group of experts on whitening procedures to get their opinions and recommendations.

Percutaneous ultrasound-guided chemical parathyroid ablation for treatment of primary hyperparathyroidism in dogs

OBJECTIVE

To evaluate the efficacy, feasibility, and safety of ultrasound-guided chemical ablation of parathyroid masses in dogs with primary hyperparathyroidism.

DESIGN

Prospective clinical trial.

ANIMALS

8 dogs.

PROCEDURE

In all dogs, a solitary parathyroid mass was evident ultrasonographically. Dogs were anesthetized with propofol, and a 27-gauge needle was directed into the parathyroid mass under ultrasound guidance. Ethanol (96%) was injected into the mass until there was evidence of diffusion of fluid throughout the mass. Serum total calcium, ionized calcium, phosphorus, and parathyroid hormone (PTH) concentrations were monitored daily for 5 to 7 days after the ablation procedure and again 1, 3, and 6 months after the procedure. Dogs were also monitored for adverse effects. Follow-up ultrasonography was performed 5 days and 1 month after the ablation procedure.

RESULTS

One injection was required in 7 dogs, and 2 injections were required in 1. Serum total and ionized calcium concentrations were within reference ranges within 24 hours after treatment in 7 dogs and within 5 days in 1 dog. Serum PTH concentration decreased and serum phosphorus concentration increased within 24 hours after treatment in all 8 dogs. Transient hypocalcemia developed in 4 dogs during the first 5 days after treatment, but only 1 dog required treatment for hypocalcemic tetany. Hypercalcemia recurred in 1 dog 1 month after the procedure and surgical removal of the parathyroid mass was required. Other adverse effects were not reported.

CONCLUSIONS AND CLINICAL RELEVANCE

Ultrasound-guided chemical ablation of parathyroid masses is a safe and effective alternative to surgery for dogs with primary hyperparathyroidism.

Clinical experience over 48 years with pheochromocytoma

OBJECTIVE

To analyze the presentation, localization, surgical management, pathology, and long-term outcome of a large series of patients with pheochromocytomas.

SUMMARY BACKGROUND DATA

There are several areas of controversy pertaining to pheochromocytomas. Although many studies report a higher rate of malignancy for extraadrenal pheochromocytomas than for adrenal pheochromocytomas, the number of patients with the former tumor are small and statistical analysis is lacking. There has also been recent debate as to whether microscopic features of the tumor may be predictive of future behavior.

METHODS

From 1950 to 1998, the authors observed 108 pheochromocytomas in 104 patients. The outcome of these patients has been followed prospectively. The medical records of these patients were reviewed for data on the presentation, localization, surgical management, pathology, and outcome. Patient survival was analyzed using Kaplan-Meier survival distributions.

RESULTS

This study included 66 female patients and 38 male patients. The average age at surgery was 42.3 years. Sporadic cases accounted for 84% of the patients; the other 16% had multiple endocrine neoplasia type 2, von Recklinghausen's disease, von Hippel-Lindau disease, or Carney's syndrome. Of 64 adrenal tumors, 55 were initially considered benign, 6 had microscopic malignant features, and 3 had malignant disease. Mean patient follow-up was 12.6 years. To date, in five additional patients (none with microscopic disease) malignant disease developed (13% overall rate of malignancy). Recurrence occurred as late as 15 years after resection. Of 26 extraadrenal pheochromocytomas, 14 were initially considered benign, 8 had microscopic malignant features, and 4 had malignant disease. Thus, 46% of patients had either malignant disease or tumors with malignant features. Mean patient follow-up was 11.5 years. In one patient with benign disease and in one patient with malignant features, malignant disease developed (23% overall rate of malignancy). The difference in the rate of malignancy was not statistically significant between adrenal and extraadrenal pheochromocytomas. Patients with adrenal and extraadrenal pheochromocytomas also had similar rates of survival (p = NS).

CONCLUSIONS

The data suggest that patients with extraadrenal pheochromocytomas have the same risk of malignancy and the same overall survival as patients with adrenal pheochromocytomas. Lifelong follow-up of these patients is mandatory.