Adrenocortical carcinoma

Cellular Senescence in Adrenocortical Biology and Its Disorders

Cellular senescence is considered a physiological process along with aging and has recently been reported to be involved in the pathogenesis of many age-related disorders. Cellular senescence was first found in human fibroblasts and gradually explored in many other organs, including endocrine organs. The adrenal cortex is essential for the maintenance of blood volume, carbohydrate metabolism, reaction to stress and the development of sexual characteristics. Recently, the adrenal cortex was reported to harbor some obvious age-dependent features. For instance, the circulating levels of aldosterone and adrenal androgen gradually descend, whereas those of cortisol increase with aging. The detailed mechanisms have remained unknown, but cellular senescence was considered to play an essential role in age-related changes of the adrenal cortex. Recent studies have demonstrated that the senescent phenotype of zona glomerulosa (ZG) acts in association with reduced aldosterone production in both physiological and pathological aldosterone-producing cells, whereas senescent cortical-producing cells seemed not to have a suppressed cortisol-producing ability. In addition, accumulated lipofuscin formation, telomere shortening and cellular atrophy in zona reticularis cells during aging may account for the age-dependent decline in adrenal androgen levels. In adrenocortical disorders, including both aldosterone-producing adenoma (APA) and cortisol-producing adenoma (CPA), different cellular subtypes of tumor cells presented divergent senescent phenotypes, whereby compact cells in both APA and CPA harbored more senescent phenotypes than clear cells. Autonomous cortisol production from CPA reinforced a local cellular senescence that was more severe than that in APA. Adrenocortical carcinoma (ACC) was also reported to harbor oncogene-induced senescence, which compensatorily follows carcinogenesis and tumor progress. Adrenocortical steroids can induce not only a local senescence but also a periphery senescence in many other tissues. Therefore, herein, we systemically review the recent advances related to cellular senescence in adrenocortical biology and its associated disorders.

Adrenocortical carcinoma: current state of the art, ongoing controversies, and future directions in diagnosis and treatment

Adrenocortical carcinoma (ACC) is a rare, aggressive malignancy with an annual incidence of ~1 case per million population. Differentiating between ACC and benign adrenocortical tumors can be challenging in patients who present with an incidentally discovered adrenal mass, due to the limited specificity of standard diagnostic imaging. Recently, urine steroid metabolite profiling has been prospectively validated as a novel diagnostic tool for the detection of malignancy with improved accuracy over current modalities. Surgery represents the only curative treatment for ACC, although local recurrence and metastases are common, even after a margin-negative resection is performed. Unlike other intra-abdominal cancers, the role of minimally invasive surgery and lymphadenectomy in ACC is controversial. Adjuvant therapy with the adrenolytic drug mitotane is used to reduce the risk of recurrence after surgery, although evidence supporting its efficacy is limited; it is also currently unclear whether all patients or a subset with the highest risk of recurrence should receive this treatment. Large-scale pan-genomic studies have yielded insights into the pathogenesis of ACC and have defined distinct molecular signatures associated with clinical outcomes that may be used to improve prognostication. For patients with advanced ACC, palliative combination chemotherapy with mitotane is the current standard of care; however, this is associated with poor response rates (RR). Knowledge from molecular profiling studies has been used to guide the development of novel targeted therapies; however, these have shown limited efficacy in early phase trials. As a result, there is an urgent unmet need for more effective therapies for patients with this devastating disease.

The Immunotherapy Landscape in Adrenocortical Cancer

Adrenocortical carcinoma (ACC) is a rare cancer of the adrenal gland that is frequently associated with excess production of adrenal hormones. Although surgical resection may be curative in early-stage disease, few effective therapeutic options exist in the inoperable advanced or metastatic setting. Immunotherapies, inclusive of a broad array of immune-activating and immune-modulating antineoplastic agents, have demonstrated clinical benefit in a wide range of solid and hematologic malignancies. Due to the broad activity across multiple cancer types, there is significant interest in testing these agents in rare tumors, including ACC. Multiple clinical trials evaluating immunotherapies for the treatment of ACC have been conducted, and many more are ongoing or planned. Immunotherapies that have been evaluated in clinical trials for ACC include the immune checkpoint inhibitors pembrolizumab, nivolumab, and avelumab. Other immunotherapies that have been evaluated include the monoclonal antibodies figitumumab and cixutumumab directed against the ACC-expressed insulin-like growth factor 1 (IGF-1) receptor, the recombinant cytotoxin interleukin-13-pseudomonas exotoxin A, and autologous tumor lysate dendritic cell vaccine. These agents have shown modest clinical activity, although nonzero in the case of the immune checkpoint inhibitors. Clinical trials are ongoing to evaluate whether this clinical activity may be augmented through combinations with other immune-acting agents or targeted therapies.

Gender differences in human adrenal cortex and its disorders

The adrenal cortex plays pivotal roles in the maintenance of blood volume, responsiveness to stress and the development of gender characteristics. Gender differences of human adrenal cortex have been recently reported and attracted increasing interests. Gender differences occur from the developing stage of the adrenal, in which female subjects had more activated stem cells with higher renewal capacity resulting in gender-associated divergent structures and functions of cortical zonations of human adrenal. Female subjects generally have the lower blood pressure with the lower renin levels and ACE activities than male subjects. In addition, HPA axis was more activated in female than male, which could possibly contribute to gender differences in coping with various stressful events in our life. Of particular interest, estrogens were reported to suppress RAAS but activate HPA axis, whereas androgens had opposite effects. In addition, adrenocortical disorders in general occur more frequently in female with more pronounced adrenocortical hormonal abnormalities possibly due to their more activated WNT and PRK signaling pathways with more abundant activated adrenocortical stem cells present in female adrenal glands. Therefore, it has become pivotal to clarify the gender influence on both clinical and biological features of adrenocortical disorders. We herein reviewed recent advances in these fields.

Advanced adrenocortical carcinoma successfully treated with gemcitabine plus capecitabine as second-line chemotherapy

INTRODUCTION

Adrenocortical carcinoma is a rare malignant tumor with an unfavorable prognosis in the advanced stage for which second-/third-line chemotherapy is not well established.

CASE PRESENTATION

A 34-year-old woman was referred to our institution for left adrenal tumor with multiple liver metastases and tumor thrombus extending to the inferior vena cava. According to her clinical diagnosis of adrenocortical carcinoma (T4N0M1, European Network for the Study of Adrenal Tumors stage IV), we resected the left adrenal tumor and tumor thrombus. Pathological examination confirmed the adrenocortical carcinoma diagnosis. After four courses of etoposide, doxorubicin, cisplatin, and mitotane therapy, the liver metastases progressed, and we started gemcitabine, capecitabine, and mitotane therapy as second-line chemotherapy. After 7 months, significant shrinkage of the liver metastases was observed, and they remained stable over 16 months.

CONCLUSION

We reported a case of advanced adrenocortical carcinoma with significant shrinkage of liver metastases following gemcitabine, capecitabine, and mitotane therapy, with the effect maintained over 16 months.

Smoking is associated with adrenal adenomas and adrenocortical carcinomas: a nationwide multicenter analysis

MICROABSTRACT

The effect of smoking on adrenal cancer is poorly understood. A clear association of adrenal adenoma and adrenocortical carcinoma with smoking among the United States population is observed. This association points to the possibility of environmental carcinogenic and/or lifestyle factors contributing to adrenal cancer formation. Our results support the association of tobacco use with adrenal adenomas and adrenal cortical carcinoma.

BACKGROUND

Smoking has been suggested as a risk factor for adrenal cortical carcinoma (ACC), but this hypothesis has only been inferred from a single study using all types of adrenal cancers including pheochromocytoma, neuroblastoma, as well as ACC. Given the high rate of tobacco use in West Virginia, we hypothesized that smoking might contribute to increased prevalence of ACC.

MATERIALS AND METHODS

De-identified institutional review board-exempted records were analyzed in the Surveillance, Epidemiology, and End Results (SEER) Program from 2001-2016 and in patients from the United States nationwide, multicenter TriNetX database of 41,063,707 patients from 2008-2018. In addition, the state-level ratio of smoking to ACC prevalence was computed in all 50 states using data from SEER and the Center for Disease Control. West Virginia Health System data from 2008-2018 was extracted to confirm population-level findings. Melanoma was used as a cancer control in both databases.

RESULTS

6,946 ACC cases were identified. West Virginia had the highest smoking rate and the second highest rate of ACC. A significant association was found between smoking and ACC (Pearson correlation coefficient r = 0.4887, p=.0004). From 2008 to 2018 using TriNetX, 846 ACC and 36,434 AA were extracted. Both adrenal neoplasm cohorts had increased prevalence of tobacco use compared with melanoma controls, where 23.5% were smokers compared to 36.4% and 33.9% in the ACC and AA groups, respectively (p<0.0001 each).

CONCLUSION

To our knowledge, this is the first United States population-based study supporting smoking as a risk factor for adrenal carcinogenesis and ACC.

Apoptosis regulation in adrenocortical carcinoma

Apoptosis evading is a hallmark of cancer. Tumor cells are characterized by having an impaired apoptosis signaling, a fact that deregulates the balance between cell death and survival, leading to tumor development, invasion and resistance to treatment. In general, patients with adrenocortical carcinomas (ACC) have an extremely bad prognosis, which is related to disease progression and significant resistance to treatments. In this report, we performed an integrative review about the disruption of apoptosis in ACC that may underlie the characteristic poor prognosis in these patients. Although the apoptosis has been scarcely studied in ACC, the majority of the deregulation phenomena already described are anti-apoptotic. Most importantly, in a near future, targeting apoptosis modulation in ACC patients may become a promising therapeutic.

MECHANISMS OF ENDOCRINOLOGY: Cell cycle regulation in adrenocortical carcinoma

Adrenocortical carcinomas (ACCs) are rather rare endocrine tumors that often have a poor prognosis. The reduced survival rate associated with these tumors is due to their aggressive biological behavior, combined with the scarcity of effective treatment options that are currently available. The recent identification of the genomic alterations present in ACC have provided further molecular mechanisms to develop consistent strategies for the diagnosis, prevention of progression and treatment of advanced ACCs. Taken together, molecular and genomic advances could be leading the way to develop personalized medicine in ACCs similarly to similar developments in lung or breast cancers. In this review, we focused our attention to systematically compile and summarize the alterations in the cell cycle regulation that were described so far in ACC as they are known to play a crucial role in cell differentiation and growth. We have divided the analysis according to the major transition phases of the cell cycle, G1 to S and G2 to M. We have analyzed the most extensively studied checkpoints: the p53/Rb1 pathway, CDC2/cyclin B and topoisomerases (TOPs). We reached the conclusion that the most important alterations having a potential application in clinical practice are the ones related to p53/Rb1 and TOP 2. We also present a brief description of on-going clinical trials based on molecular alterations in ACC. The drugs have targeted the insulin-like growth factor receptor 1, TOP 2, polo-like kinase1, cyclin-dependent kinase inhibitors, p53 reactivation and CDC25.

Applications of high-resolution magic angle spinning MRS in biomedical studies II-Human diseases

High-resolution magic angle spinning (HRMAS) MRS is a powerful method for gaining insight into the physiological and pathological processes of cellular metabolism. Given its ability to obtain high-resolution spectra of non-liquid biological samples, while preserving tissue architecture for subsequent histopathological analysis, the technique has become invaluable for biochemical and biomedical studies. Using HRMAS MRS, alterations in measured metabolites, metabolic ratios, and metabolomic profiles present the possibility to improve identification and prognostication of various diseases and decipher the metabolomic impact of drug therapies. In this review, we evaluate HRMAS MRS results on human tissue specimens from malignancies and non-localized diseases reported in the literature since the inception of the technique in 1996. We present the diverse applications of the technique in understanding pathological processes of different anatomical origins, correlations with in vivo imaging, effectiveness of therapies, and progress in the HRMAS methodology.

Targeted Molecular Imaging in Adrenal Disease-An Emerging Role for Metomidate PET-CT

Adrenal lesions present a significant diagnostic burden for both radiologists and endocrinologists, especially with the increasing number of adrenal ‘incidentalomas’ detected on modern computed tomography (CT) or magnetic resonance imaging (MRI). A key objective is the reliable distinction of benign disease from either primary adrenal malignancy (e.g., adrenocortical carcinoma or malignant forms of pheochromocytoma/paraganglioma (PPGL)) or metastases (e.g., bronchial, renal). Benign lesions may still be associated with adverse sequelae through autonomous hormone hypersecretion (e.g., primary aldosteronism, Cushing’s syndrome, phaeochromocytoma). Here, identifying a causative lesion, or lateralising the disease to a single adrenal gland, is key to effective management, as unilateral adrenalectomy may offer the potential for curing conditions that are typically associated with significant excess morbidity and mortality. This review considers the evolving role of positron emission tomography (PET) imaging in addressing the limitations of traditional cross-sectional imaging and adjunctive techniques, such as venous sampling, in the management of adrenal disorders. We review the development of targeted molecular imaging to the adrenocortical enzymes CYP11B1 and CYP11B2 with different radiolabeled metomidate compounds. Particular consideration is given to iodo-metomidate PET tracers for the diagnosis and management of adrenocortical carcinoma, and the increasingly recognized utility of ¹¹C-metomidate PET-CT in primary aldosteronism.

Adrenal cortical carcinoma with tumor thrombus extension into the right atrium: A case report

Adrenal cortical carcinoma (ACC) is a rare aggressive malignant tumor associated with a poor prognosis. Patients with ACC usually present with abnormal hormone secretion, tumor growth or encroachment on the surrounding viscera. An early diagnosis of ACC is considered challenging. The present study reports a case of ACC with tumor thrombus extension into the inferior vena cava and right atrium. A 33-year-old male patient exhibited symptoms of gynecomastia and abdominal distention, which were due to the abnormal hormone secretion levels and to the presence of a large mass in the right adrenal gland. An en bloc resection of the tumor was the selected treatment option. Extirpation of the tumor thrombus was performed by means of extracorporeal circulation. No signs of metastasis or recurrence were identified at the 1-month follow-up.

Primary adrenal sarcomatoid carcinoma metastatic to the lung: Case report and review of the literature

Adrenal sarcomatoid carcinoma is a rare adrenal carcinoma. To the best of our knowledge, only 11 cases have been reported since 1987. Adrenal sarcomatoid carcinoma presents a diagnostic challenge due to its atypical symptoms and histological patterns. At the time of diagnosis, a large percentage of patients are already at the metastatic stage and succumb within a few months. The present study reports a case of a 59-year-old man presenting with asthenia and weight loss with adrenal sarcomatoid carcinoma metastatic to the lung. A computed tomography (CT) scan and ultrasonography of the patient's abdomen suggested a large homogeneous mass in the right adrenal gland, and a CT scan of his chest suggested lung metastasis. Right adrenalectomy was performed. Histological examination revealed that the tumor was composed of sarcomatous and carcinomatous differentiation elements. Immunohistochemical examination revealed tumor cell positivity for vimentin and cytokeratin. At the 6-month follow-up the patient exhibited no disease progression and refused further proposed treatment. The patient was alive at the time of writing the current report. The present case report additionally reviews the literature, for the purpose of raising awareness of these rare lesions and assisting in achieving accurate diagnoses and effective treatment.

Does nephrectomy during radical adrenalectomy for stage II adrenocortical cancer affect patient outcome?

PURPOSE

To evaluate if including nephrectomy in the standard surgical approach to stage II adrenocortical cancer (i.e., adrenalectomy) might modify oncologic outcome of patients.

METHODS

We performed a retrospective analysis involving 41 patients with stage II adrenocortical cancer (ACC) who had undergone radical surgery. Patients were divided into two groups according to the surgical procedure: group A = radical adrenalectomy alone, group AN = radical adrenalectomy + radical nephrectomy. Oncologic effectiveness of the procedures was tested comparing the recurrence-free and overall survival of patients of A vs AN groups.

RESULTS

The group A consisted of 25 patients and group AN of 16 patients. No differences were noted between the two groups in terms of demographic data and ACC characteristics. During follow-up, 15/25 (60 %) patients of group A vs 14/16 (87.5 %) patients of group AN experienced a recurrence, after a median of 36 months in group A and 10 months in group AN (p = 0.06); a significant impairment of renal function was recorded in patients of AN group with respect to those of group A. Finally, 13/25 (52 %) patients of group A and 10/16 (62.5 %) patients of group AN died due to ACC-related causes. No differences in survival times were noted (p = 0.3).

CONCLUSION

Our study suggests that adjunctive nephrectomy does not modify the oncologic results of adrenalectomy in the treatment of stage II ACC in terms of recurrence-free and overall survival. Thus, when there are no signs of ACC local invasion, surgeon should make every effort to preserve the kidney.

Targeting polo-like kinase 1, a regulator of p53, in the treatment of adrenocortical carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) is an aggressive cancer with a 5 year survival rate of 20-30 %. Various factors have been implicated in the pathogenesis of ACC including dysregulation of the G2/M transition and aberrant activity of p53 and MDM2. Polo-like kinase 1 (PLK-1) negatively modulates p53 functioning, promotes MDM2 activity through its phosphorylation, and is involved in the G2/M transition. Gene expression profiling of 44 ACC samples showed that increased expression of PLK-1 in 29 % of ACC. Consequently, we examined PLK-1's role in the modulation of the p53 signaling pathway in adrenocortical cancer.

METHODS

We used siRNA knock down PLK-1 and pharmacological inhibition of PLK-1 and MDM2 ACC cell lines SW-13 and H295R. We examined viability, protein expression, p53 transactivation, and induction of apoptosis.

RESULTS

Knocking down expression of PLK-1 with siRNA or inhibition of PLK-1 by a small molecule inhibitor, BI-2536, resulted in a loss of viability of up to 70 % in the ACC cell lines H295R and SW-13. In xenograft models, BI-2536 demonstrated marked inhibition of growth of SW-13 with less inhibition of H295R. BI-2536 treatment resulted in a decrease in mutant p53 protein in SW-13 cells but had no effect on wild-type p53 protein levels in H295R cells. Additionally, inhibition of PLK-1 restored wild-type p53's transactivation and apoptotic functions in H295R cells, while these functions of mutant p53 were restored only to a smaller extent. Furthermore, inhibition of MDM2 with nutlin-3 reduced the viability of both the ACC cells and also reactivated wild-type p53's apoptotic function. Inhibition of PLK-1 sensitized the ACC cell lines to MDM2 inhibition and this dual inhibition resulted in an additive apoptotic response in H295R cells with wild-type p53.

CONCLUSIONS

These preclinical studies suggest that targeting p53 through PLK-1 is an attractive chemotherapy strategy warranting further investigation in adrenocortical cancer.

Rare incidence of primary adrenocortical carcinosarcoma: A case report and literature review

Adrenocortical carcinoma (ACC) is a rare, but highly aggressive type of tumor with an incidence of one to two per million annually. Adrenocortical carcinosarcoma is an exceptional variant of ACC, which is characterized by the presence of histological regions of carcinoma and sarcoma. To date, to the best of our knowledge, there have only been 12 reported cases of adrenocortical carcinosarcoma. In the present study, a case of primary, non-functional adrenocortical carcinosarcoma is described, as well as a review of the literature to raise awareness of this particularly rare type of malignant neoplasm that is associated with a worse diagnosis and prognosis than adrenocortical carcinoma. In the present study, the patient underwent a laparoscopic left adrenalectomy and the tumor was dissected without complication from the left kidney. Microscopic observations showed the tumor comprised of epithelial and spindle cell components. The patient did not exhibit signs of tumor recurrence at the one-month follow-up. The potential diagnosis of adrenocortical carcinosarcoma must be considered when diagnosing adrenal malignancies in adults. In addition, comphrensive imunohistochemical staining may be required to identify possible sarcomatous patterns. To the best of our knowledge, the present case is the first to report an incidence of adrenocortical carcinosarcoma in China. Details of the patient are presented and the pathology of adrenocortical carcinosarcoma is discussed.

MicroRNA era: the importance for diagnosis and prognosis of adrenocortical tumors

MicroRNAs play an essential role in posttranscriptional regulation of gene expression. They are evolutionary conserved, small, noncoding, 19–22-nucleotide RNAs, whose abnormalities, such as up- or downregulated expression, have been associated with several neoplasms, including adrenocortical tumors. Expression levels of distinct microRNAs can distinguish benign from malignant adrenal tumors. This current review provides recent data on the miRNAs profile in benign and malignant adrenocortical tumors diagnosed in adult and pediatric patients.

Adrenocortical carcinoma: what the surgeon needs to know. Case report and literature review

Adrenocortical carcinoma is a rare and aggressive cancer and its prognosis is frequently unsatisfactory. Due to its rarity there's a lack of prospective randomized studies. Without experience in the approach of this kind of tumor, managing becomes challenging and, moreover, we have only few recommendations, based on weak evidence. We report a case that has some peculiarities and is an excellent food for thought. Then we deal with a literature review to highlight and summarize most significant aspects of epidemiology, clinic, diagnosis, therapy and prognosis in an exquisitely surgical point of view.

Nuclear medicine imaging of endocrine neoplasms

Endocrine tumors are hormonally active benign or malignant neoplasms arising within endocrine organs or from specialized cells of the amine precursor uptake and decarboxylation system. The detection rate of these tumors is increasing as a result of sensitive biochemical tests and high-resolution diagnostic imaging. Medical imaging has become a key component in the diagnosis and staging of endocrine malignancies; however, despite the impressive advances in computed tomography (CT) and MRI, detection of small primary tumors and metastases continues to be a challenge. Functional imaging techniques use radiopharmaceuticals targeted at unique tumor cellular processes in order to provide sensitive and highly specific whole-body imaging. Functional imaging allows prediction of the efficacy of radionuclide or receptor-based therapies and surveillance after therapy. Advances in imaging have not been limited to radiopharmaceuticals. Hybrid scanner technology in the form of PET/CT and single photon emission computed tomography (SPECT)/CT, designed to combine functional images with anatomic maps, has further improved the diagnostic accuracy. High-resolution hybrid imaging when deployed with novel PET and SPECT radiopharmaceuticals has the potential to dramatically change, individualize, and optimize imaging plans based on the histological grade, degree of differentiation, and genetic profile of each patient's endocrine neoplasm.

A case of androgen-secreting adrenal carcinoma with non-classical congenital adrenal hyperplasia

Androgen excess is one of the most common and disturbing endocrine disorder of reproductive-aged women, affecting approximately 7% of this population Androgen excess results in the development of androgenic features in the women affected, with the development of hirsutism, androgenic alopecia, ovulatory dysfunction, and, if extreme, even virilization and masculinization. Adrenocortical carcinoma (ACC) is a rare malignancy accounting for 0.02% of all annual cancers reported. About 60% are functional tumors secreting hormones, with its consequent clinical manifestations, the Cushing's syndrome due to cortisone, virilization due to androgens, feminization due to estrogens, or hypertension due to aldosterone. Adrenal tumors that secrete androgens exclusively are extremely rare. Here, we present a rare case of androgen-secreting adrenocortical carcinoma with non-classical congenital adrenal hyperplasia.

Metabolomic profile of the adrenal gland: from physiology to pathological conditions

In this study, we i) assessed the metabolic profile of the normal adrenal cortex and medulla of adult human subjects by means of (1)H-high-resolution magic-angle spinning nuclear magnetic resonance (HRMAS NMR) spectroscopy; ii) compared the biochemical profile of adenoma (Ad), adrenal cortical carcinoma (ACC), and pheochromocytoma (PCC) samples with that of healthy adrenal tissue samples; and iii) investigated the metabolic differences between ACCs and Ads as well as between ACCs and PCCs. Sixty-six tissue samples (13 adrenal cortical tissue, eight medullary tissue, 13 Ad, 12 ACC, and 20 PCC samples) were analyzed. Adrenaline and noradrenaline were undetectable in cortical samples representing the metabolic signature of the tissue derived from neural crest. Similarity between the metabolic profile of Ads and that of the normal adrenal cortex was shown. Inversely, ACC samples clearly made up a detached group exhibiting the typical stigmata of neoplastic tissue such as choline-containing compounds, biochemical markers of anaerobic processes, and increased glycolysis. Significantly higher levels of lactate, acetate, and total choline-containing compounds played a major role in the differentiation of ACCs from Ads. Moreover, the high fatty acid content of ACCs contributed to the cluster identification of ACCs. Of the 14 sporadic PCC samples, 12 exhibited predominant or exclusive noradrenaline secretion. The noradrenaline:adrenaline ratio was inverted in the normal medullary tissue samples. Multiple endocrine neoplasia type 2- and NF1-related PCC samples exhibited both adrenaline and noradrenaline secretion. In the von Hippel-Lindau disease-related PCC samples, only noradrenaline secretion was detected by HRMAS NMR spectroscopy. This study is one of the first applications of metabolomics to adrenal pathophysiology and it is the largest study to report HRMAS NMR data related to the adrenal cortex and adrenal cortical tumors.

Mitotane levels predict the outcome of patients with adrenocortical carcinoma treated adjuvantly following radical resection

CONTEXT

Mitotane plasma concentrations ≥ 14 mg/l have been shown to predict tumor response and better survival in patients with advanced adrenocortical carcinoma (ACC). A correlation between mitotane concentrations and patient outcome has not been demonstrated in an adjuvant setting.

OBJECTIVE

To compare recurrence-free survival (RFS) in patients who reached and maintained mitotane concentrations ≥ 1 4 mg/l vs patients who did not.

DESIGN AND SETTING

Retrospective analysis at six referral European centers.

PATIENTS

Patients with ACC who were radically resected between 1995 and 2009 and were treated adjuvantly with mitotane targeting concentrations of 14-20 mg/l.

MAIN OUTCOME MEASURES

RFS (primary) and overall survival (secondary).

RESULTS

Of the 122 patients included, 63 patients (52%) reached and maintained during a median follow-up of 36 months the target mitotane concentrations (group 1) and 59 patients (48%) did not (group 2). ACC recurrence was observed in 22 patients of group 1 (35%) and 36 patients in group 2 (61%). In multivariable analysis, the maintenance of target mitotane concentrations was associated with a significantly prolonged RFS (hazard ratio (HR) of recurrence: 0.418, 0.22-0.79; P=0.007), while the risk of death was not significantly altered (HR: 0.59, 0.26-1.34; P=0.20). Grades 3-4 toxicity was observed in 11 patients (9%) and was managed with temporary mitotane discontinuation. None of the patients discontinued mitotane definitively for toxicity.

CONCLUSIONS

Mitotane concentrations ≥ 14 mg/l predict response to adjuvant treatment being associated with a prolonged RFS. A monitored adjuvant mitotane treatment may benefit patients after radical removal of ACC.

Adrenocortical carcinoma: clinicopathological features, prognostic factors and outcome

OBJECTIVE

The purpose of this study was to investigate the clinicopathological characteristics and treatment outcomes of patients with adrenocortical carcinoma (AC).

METHODS

Twenty-four patients (10 females and 14 males) diagnosed with AC between 1998 and 2009 were evaluated. Clinical features and outcomes were reviewed.

RESULTS

Median age was 46.5 years. One (4%) patient was classified as stage I, 10 (42%) were classified as stage II, 8 (33%) were classified as stage III and 5 (21%) were classified as stage IV. Tumor sizes ranged from 3 to 22 cm with a mean diameter of 11 cm. Five patients were locally inoperable at initial diagnosis. In addition to surgery, 2 of 19 patients were treated with an adjuvant cisplatin plus etoposide regimen. Sixteen patients were treated with chemotherapy after recurrence. Median survival time was 18 months. The 1- and 5-year overall survival estimates were 73 and 48%, respectively. Mean survival times for male and female patients were 58 and 12 months, respectively (p = 0.046). Early T stage (p = 0.04), lymph node negativity (p < 0.001), the absence of distant metastases (p < 0.001) and early stage (p < 0.001) were correlated with overall survival.

CONCLUSION

AC is a rare disease with a poor prognosis. There are correlations between gender, stage and survival.

Adrenal tumours are more predominant in females regardless of their histological subtype: a review

OBJECTIVES

Adrenal tumours are a heterogeneous group of rare tumours. The aim of this article was to critically review gender-specific differences in the incidence, prognosis and symptoms of the different subtypes of adrenal tumours.

METHODS

Data acquisition regarding gender differences in adrenal tumours was performed using MEDLINE searches with combinations of the following keywords: adrenal tumours, gender, sex differences, adrenocortical carcinoma, pheochromocytoma, incidentaloma, risk factors and genetic aspects.

RESULTS

Data are scarce in the literature concerning the effects of gender on adrenal lesions. Although the incidence of most types of tumours (other than breast cancer and other gender-related tumours) is higher in men than in women, evidence suggests that adrenal tumours (i.e. incidentalomas, adrenal carcinomas, oncocytomas and adrenal cysts) are more frequent in women than in men. In addition, female patients have significantly increased numbers of self-reported signs and symptoms of pheochromocytoma than male patients, irrespective of biochemical phenotype and tumour presentation. Relatively little research has been performed examining the reasons for these disparities. However, hormonal interactions involving complex adrenal, endocrine and neurocrine functions together with variations in hormonal receptor sensitivity have been hypothesised to be involved.

CONCLUSION

Gender differences exist in the incidence and symptoms of several subtypes of adrenal tumours. The reasons for these disparities are not well established. In addition to epidemiological data, these results need to be further investigated to better understand the role of genetic and hormonal predispositions in the development, behaviour and aggressiveness of adrenal tumours.

A pregnant patient with adrenocortical carcinoma: case report

BACKGROUND

Coexistence of an adrenocortical carcinoma and pregnancy is extremely rare with only 25 described cases so far, and has a poor prognosis.

CASE REPORT

We report the case of a 28-year-old patient with adrenocortical carcinoma initially presenting with Cushing's syndrome and pre-eclampsia in the 22nd week of gestation, treated in our department. She underwent adrenalectomy, but eventually died from metastatic disease. We focus on existing treatment options and concerns for this rare malignancy during pregnancy.

CONCLUSION

Early diagnosis and surgery are the cornerstones for better outcome.

Adrenal neoplasms

Adenoma, myelolipoma, phaeochromocytoma, metastases, adrenocortical carcinoma, neuroblastoma, and lymphoma account for the majority of adrenal neoplasms that are encountered in clinical practice. A variety of imaging methods are available for evaluating adrenal lesions including ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine techniques such as meta-iodobenzylguanidine (MIBG) scintigraphy and positron-emission tomography (PET). Lipid-sensitive imaging techniques such as unenhanced CT and chemical shift MRI enable detection and characterization of lipid-rich adenomas based on an unenhanced CT attenuation of ≤ 10 HU and signal loss on opposed-phase compared to in-phase T1-weighted images, respectively. In indeterminate cases, an adrenal CT washout study may differentiate adenomas (both lipid-rich and lipid-poor) from other adrenal neoplasms based on an absolute percentage washout of >60% and/or a relative percentage washout of >40%. This is based on the principle that adenomas show rapid contrast washout while most other adrenal neoplasms including malignant tumours show slow contrast washout instead. ¹⁸F-2-fluoro-2-deoxy-d-glucose-PET (¹⁸FDG-PET) imaging may differentiate benign from malignant adrenal neoplasms by demonstrating high tracer uptake in malignant neoplasms based on the increased glucose utilization and metabolic activity found in most of these malignancies. In this review, the multi-modality imaging appearances of adrenal neoplasms are discussed and illustrated. Key imaging findings that facilitate lesion characterization and differentiation are emphasized. Awareness of these imaging findings is essential for improving diagnostic confidence and for reducing misinterpretation errors.

Clinical and imaging overview of functional adrenal neoplasms

Adrenal adenoma, adrenocortical carcinoma, pheochromocytoma and neuroblastoma are four discrete adrenal neoplasms that have the potential for functional activity. Functional adrenal neoplasms can secrete cortisol, aldosterone, sex hormones or catecholamines. These heterogeneous groups of tumors show varied biological behavior and clinical outcomes. These neoplasms are encountered with increasing clinical frequency as a result of an expansion in the volume of medical imaging carried out. The clinical presentation, including prognosis and treatment options, and the imaging features of these neoplasms are discussed. The key radiological observations of each of these neoplasms are shown using multimodality images. Familiarity with the clinical and imaging features of these neoplasms improves diagnosis, and facilitates appropriate clinical decision-making and patient management.

A rare case of an aldosterone secreting metastatic adrenocortical carcinoma and papillary thyroid carcinoma in a 31-year-old male

We report a rare synchronous presentation of adrenocortical carcinoma (ACC) and papillary thyroid carcinoma (PTC). A 31-year-old male first presented with a large left adrenal mass that was identified during the workup for refractory hypertension due to hyperaldosteronism. The mass was removed surgically with pathology showing ACC. The patient was then treated with adjuvant radiation therapy and mitotane chemotherapy. Four months post ACC resection, metastatic ACC to the right upper lung and PTC in the left lobe of the thyroid were found in surveillance imaging. He subsequently developed pulmonary, contralateral adrenal and brain metastases from his ACC. Li Fraumeni syndrome and Multiple Endocrine Neoplasia Type I (MEN I) were considered, but testing of both P53 and menin genes showed no mutation. We also performed a review of the literature and found three similar cases, however gene mutation analysis was not performed..

Pulmonary resection for metastatic adrenocortical carcinoma: the National Cancer Institute experience

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare neoplasm with a high propensity for locoregional recurrences and distant metastases for which there are no effective systemic therapies. This study was undertaken to determine outcomes of patients undergoing pulmonary metastasectomy for ACC.

METHODS

A single-institution retrospective review was performed of patients undergoing pulmonary metastasectomy for ACC from 1979 to 2010.

RESULTS

Twenty-six patients underwent 60 pulmonary metastasectomies. Fifteen patients (58%) underwent unilateral thoracotomy, 6 (23%) had staged thoracotomies, and 5 (19%) underwent median sternotomy as the initial thoracic procedure. Median number and size of lesions were 6 and 2 cm, respectively. Twenty-three patients (88%) were rendered free of disease in the lung, and 14 (54%) were rendered completely free of disease. Median overall and 5-year actuarial survivals from initial pulmonary metastasectomy were 40 months and 41%, respectively, with a median potential follow-up of 120 months. Median recurrence-free survival (RFS) and 5-year RFS for ipsilateral thoracic recurrences were 6 months, and 25%, respectively. The median RFS in the contralateral thorax was 5 months. Time to first recurrence after adrenalectomy and T stage of the primary tumor, but not adjuvant or neoadjuvant chemotherapy, were associated with increased overall survival after pulmonary metastasectomy.

CONCLUSIONS

This study represents the most comprehensive review of outcomes of patients undergoing pulmonary metastasectomy for ACC. Given the lack of effective systemic therapies, pulmonary metastasectomy may be beneficial in properly selected patients.

Metastatic adrenocortical carcinoma presenting simultaneously with Cushing's and Conn's syndromes: a case report

We report the first case of adrenocortical carcinoma secreting cortisol (Cushing's syndrome) and aldosterone (Conn's syndrome) with extensive distant metastasis at the time of diagnosis. A 72-year-old male with exertional dyspnea sought evaluation at our institution. The pattern of tumor spread (lung, pleura, bone and adrenal gland) and respiratory symptoms secondary to the tumor led clinicians to diagnose the primary tumor site as lung cancer and the adrenal mass as a metastatic site. However, endocrinologic studies and a biopsy revealed the primary site to be adrenocortical carcinoma. After histopathologic confirmation, the patient was treated with palliative chemotherapy, including mitotane, cisplatin, etoposide and doxorubicin. The patient died on the 14th day after chemotherapy of rapidly progressive and unexpected pneumonia, which was thought to be an opportunistic infection secondary to Cushing's syndrome. Our case suggests that a thorough endocrinologic investigation is important in patients with an adrenal mass and clinicians should be aware that patients with adrenocortical carcinoma and Cushing's syndrome are susceptible to infections and need to be observed carefully for the possible development of unrecognized opportunistic infections.

Contemporary management of adrenocortical carcinoma

CONTEXT

Adrenocortical carcinoma (ACC) is a rare and typically aggressive malignancy. Available recommendations are based primarily on retrospective series or expert opinions, and only few prospective clinical studies have yet been published.

OBJECTIVE

To combine the available evidence for diagnostic work-up and treatment of ACC to a contemporary recommendation on the management of this disease.

EVIDENCE ACQUISITION

We conducted a systematic literature search for studies conducted on humans and published in English using the Medline/PubMed database up to 31 January 2011. In addition, we screened published abstracts at meetings and several Web sites for recommendations on ACC management.

EVIDENCE SYNTHESIS

In patients with suspected localised ACC, a thorough endocrine and imaging work-up is followed by complete (R0) resection of the tumour by an expert surgeon. In experienced hands, laparoscopic adrenalectomy is probably as effective and safe for localised and noninvasive ACC as open surgery. Most clinicians agree that mitotane should be used as adjuvant therapy in the majority of patients, as they have a high risk for recurrence. An international panel has suggested using tumour stage, resection status, and the proliferation marker Ki67 as guidance for or against adjuvant therapy. In patients with advanced disease at presentation or recurrence not amenable to complete resection, a surgical approach is frequently inadequate. In these cases, mitotane alone or in combination with cytotoxic drugs is the treatment of choice. The most promising regimens (etoposide, doxorubicin, cisplatin plus mitotane, and streptozotocin plus mitotane) are currently compared in an international phase 3 trial, and results should be available by the end of 2011. Several targeted therapies are under investigation and may lead to new treatment options. Management of endocrine manifestations with steroidogenesis inhibitors is required in patients suffering uncontrolled hormone excess.

CONCLUSIONS

Detailed recommendations are provided to guide the management of patients with ACC.

Liver resection and ablation for metastatic adrenocortical carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare disease without effective chemotherapy treated most appropriately with resection. The aim of this study was to evaluate our experience with liver resection for metastatic ACC.

METHODS

This study is a retrospective review of patients who underwent liver resection or radiofrequency ablation (RFA) for ACC from 1979 to 2009.

RESULTS

A total of 27 patients were identified. Of the 27, 19 underwent liver resection. Of the 19, 10 had a single liver lesion, and 18 of 19 were rendered free of disease in the liver, although only 11 of 19 were rendered completely free of disease because of extrahepatic disease (EHD). Of the 19, 13 had synchronous EHD. Also, 6 of 17 remained disease free in the liver at a median follow-up of 6.2 years (status of 2 of 19 was unknown). Of the 27 patients, 8 underwent RFA, 7 of 8 became free of disease in the liver, and 5 of 7 had EHD. No patients responded to prior chemotherapy. Median overall survival and survival of patients who underwent liver resection or RFA were both 1.9 years (0.2-12 + years); 5-year actuarial survivals were 29% and 29%, respectively. Disease-free interval (DFI) greater than 9 months from primary resection was associated with longer survival (median 4.1 vs 0.9 years; P = .013).

CONCLUSIONS

This study is a tertiary institution series of liver resection and RFA for ACC. Given the lack of effective systemic treatment options and the safety of resection and ablation, liver resection or RFA may be considered in selected patients with ACC metastatic to the liver especially with a long DFI.

Androgen- and estrogen-secreting adrenal cancers

Androgen-secreting adrenal cancers are extremely rare malignancies, accounting for only a tiny proportion of the total number of women presenting with signs of androgen excess. Estrogen-secreting adrenal cancers are rarer still. Understanding how these tumors work benefits from an appreciation of adrenal steroid biosynthesis, as it is said that secretion in cancers is an anarchic version of normal adrenal function. Selection of patients in whom we should have a high suspicion of a malignancy is vital, so that biochemical investigation and imaging is deployed appropriately. When an adrenal tumor is found to secrete androgens or estrogens to excess, it can be difficult to confirm that it is a cancer, as there is significant overlap in the secretory patterns and imaging appearances of benign and malignant disease. The most reliable indicator of malignancy in these tumors remains the presence of metastases. Treatment is essentially surgical, although the role of mitotane is one undergoing evaluation.

Management of endocrine manifestations and the use of mitotane as a chemotherapeutic agent for adrenocortical carcinoma

Adrenal cortical carcinoma (ACC) is a rare malignancy in which patients have poor overall 5-year survival. Patients with ACC can present with symptoms of hormone excess, including Cushing's syndrome, virilization, feminization, or--less frequently--hypertension with hypokalemia. In many patients with ACC, advanced disease at presentation precludes surgery or is followed by local relapse or distant metastatic disease that cannot be managed surgically. In these instances, chemotherapy is often tried, but its limited efficacy all too often leaves the problem of persistent hormonal excess. Physicians who treat patients with ACC and severe hypercortisolism should recognize that uncontrolled hormone production is a malignant disease, which has severe consequences that require aggressive management. Because chemotherapy benefits only a small percentage of patients, steroidogenesis inhibitors, including mitotane, ketoconazole, metyrapone, and etomidate, should be used singly or in combination even as chemotherapy is administered. Diligent management with frequent adjustments is required, especially in patients with chemotherapy-refractory tumors that continue to grow. In the absence of randomized, controlled trials, adjuvant use of mitotane remains controversial, although the authors of a recent case-control study argue for its use. Despite difficulty administering effective doses, most clinicians agree that mitotane should be used if the tumor cannot be removed surgically or should be used as adjuvant therapy if there is a high likelihood of recurrence. The option of long-term monotherapy is restricted to patients who tolerate mitotane and either experience a clinical response or are at high risk for recurrence. Recommendations are provided to help manage patients with this difficult disease and to improve the quality of their lives.

A rare bone-leptomeningeal metastasis from an adrenal cortical carcinoma

We report a rare bone-leptomeningeal metastasis from an adrenal cortical carcinoma (ACC). ACC is a rare malignancy and represents one of the most unusual sources of intracranial metastases (0-0.2%); the localization to the skull bone and meninges is uncommon. A 45-year-old man underwent surgery for a non-functioning ACC; 4 months later he developed a soft left frontal mass. The CT scans and MRI showed a large tumor with bone and leptomeningeal involvement. Despite chemotherapy, the lesion increased in volume, which led to local pain and right hemiparesis. Thus, the patient underwent excision of the mass; histopathological diagnosis confirmed that it was an ACC metastasis. The patient underwent standard radiation therapy after surgery. At post-operative follow-up, the patient was in a good neurological condition with no radiological evidence of a cranial recurrence; however, there was a voluminous abdominal regrowth of the primary tumor. To our knowledge, this is the second case of bone and leptomeningeal metastasis arising from an ACC. This patient report confirms the effectiveness of aggressive surgery for management of large intracranial metastases, particularly those that arise from primary tumors that are resistant to radiotherapy and chemotherapy. In our opinion, surgery represents the most appropriate treatment for voluminous intracranial metastasis - even when there are no neurological signs.

Bilateral primary adrenal non-Hodgkin's lymphoma and primary adrenocortical carcinoma--review of the literature preoperative differentiation of adrenal tumors

Most of the adrenal tumors that are incidentally detected are benign adenomas. The incidence of malignant adrenal tumors including adrenocortical carcinoma (ACC) and primary adrenal lymphoma (PAL) is rather low. As many patients with ACC and PAL are diagnosed at an advanced stage of disease, the overall survival time of both entities remains poor. The therapeutic strategies for both entities differ. Thus an early differentiation between ACC and PAL is necessary. Unfortunately hitherto preoperative diagnosis of potentially malignant adrenal masses is still a main problem in the treatment of adrenal tumors. We present the case of a 57-year-old male patient with ACC and the case of an 87-year-old male patient with PAL and provide a systematic comparison of the clinical and pathological features of both entities. In both cases clinical and radiological features resulted in an initially false diagnosis. Primary surgical therapy was performed in both patients. The patient with PAL died five months after initial surgery. The patient with ACC showed tumor progression with local and systemic recurrence despite adjuvant therapy with mitotane and additional surgical therapy. Prognosis of patients with ACC and PAL seems to be dependant on the ability to start accurate treatment without any time delay. We propose some guidelines for diagnosis and surgical management of adrenal tumors.

[Successful surgical removal of adrenocortical carcinoma growing into the inferior vena cava and the right atrium]

The authors discuss a case of a 47-year old female, who underwent a left adrenalectomy for adrenocortical carcinoma. A few months later the tumour locally recurred and spread through the inferior vena cava into the right atrium. The tumour thrombus almost completely occluded the lumen of the inferior vena cava resulting in significant hepatic congestion, ascites and oedema of the lower extremities. The whole tumour thrombus was successfully removed through the right atrium under visual control using extracorporeal circulation in deep hypothermic (20 degrees C) circulatory arrest. The locally recurred tumour from the site of the left adrenal gland was also removed a month later. The histological examination revealed moderately differentiated adrenocortical carcinoma with a proliferation rate higher than 10%. Thereafter, patient underwent adjuvant oncological therapy and she has been disease free in the last one year. Clinical data suggest that tumour thrombus of various origin that grow into the inferior vena cava can be safely removed using extracorporeal circulation (with or without cardiac arrest), and in such cases, when the primary tumour is resectable, the prognosis is relatively good.

Adrenocortical carcinoma with delayed cutaneous metastasis

Adrenal cortical carcinoma (ACC) is an uncommon and aggressive malignancy. Patients often have metastatic disease at initial presentation, with the most common sites being the liver, local lymph nodes, lungs, peritoneum and bone. Despite a high frequency of metastases, there are only isolated reports of ACC that have metastasized to the skin. Herein, we report a case of an 82-year-old woman who presented with a cyst-like lesion on her back, which on biopsy proved to be ACC metastatic from a primary tumor diagnosed 30 years previously.

Diagnosis and management of adrenal cortical carcinoma

Adrenal cortical carcinoma is a relatively uncommon malignancy that represents a significant clinical challenge for the development of optimal treatment strategies. Historically, successful treatment has relied upon rapid identification of the lesion, accurate staging with diagnostic imaging, and complete surgical extirpation. Although the framework of a successful treatment paradigm still relies on these steps, advances in diagnostic imaging have led to increased accuracy in diagnosis, and advances in laparoscopic surgical technique have served to reduce morbidity for patients facing treatment. This review focuses on a discussion of advances in modalities for the diagnosis and treatment of adrenal cortical carcinoma amenable to curative therapy. Patients that present with metastatic or locally advanced disease generally are treated with mitotane-based chemotherapy with or without the addition of cytotoxic drugs. Contemporary results of this treatment approach are presented in this review as well as a discussion of further directions for the treatment of patients with advanced disease.

Fine-needle aspiration of adrenal cortical carcinoma: cytologic spectrum and diagnostic challenges

We reviewed the cytologic features of 20 adrenal cortical carcinomas (ACCs; 9 primary and 11 metastatic) from 19 patients and highlighted diagnostic pitfalls. The mean size of primary ACCs was 11.9 cm, and that of metastatic ACCs was 3.0 cm. The metastatic sites were liver, lung, lymph node, soft tissue, and bone. Primary and metastatic ACCs were cytologically similar and showed a wide range of features varying from well-differentiated tumor resembling a benign cortical lesion or low-grade neuroendocrine tumor to poorly differentiated pleomorphic tumor mimicking poorly differentiated carcinoma, melanoma, or high-grade sarcoma. The common cytologic features were hypercellularity (70% of cases), necrotic debris in the background (70%), moderate to marked nuclear pleomorphism (80%), mitotic figures (90%), and prominent nucleoli (60%). Twenty percent of cases exhibited all 5 features; 40% exhibited 4 features, and 40% exhibited 3 features. Necrosis and/or mitosis were found in all cases, even in tumors with bland cytologic features. Cytologic, immunophenotypic, and ultrastructural findings should be correlated with clinical and radiologic information for achieving a proper cytologic diagnosis.

Indications and Results of Surgery for Incidentally Found Adrenal Tumors

INTRODUCTION

The accidental discovery of an adrenal mass called incidentaloma has become an increasingly frequent clinical problem with the question of a correct and appropriate therapeutic approach being the subject of controversial discussions.

MATERIALS AND METHODS

Clinical charts of 52 patients (22 male, 30 female) who underwent adrenalectomy for an incidentaloma at our institution between 1987 and 2001 were reviewed.

RESULTS

Median age was 56.4 years. Reasons for surgery were unclear significance in 22 patients, suspicion of malignancy in 5, increase in size in 8, maximum tumor diameter of more than 5 cm in 7, fear of malignancy in 1, and subclinical secretion of cortisol in 5 patients. No data were available for 4 patients. Surgical resection was performed using a conventional transabdominal approach in 28 patients, a conventional dorsal approach in 17 patients, and an endoscopic retroperitoneal approach in 7 patients. Histopathologic examination ruled out adrenal adenoma in 32 patients, adrenal myelolipoma in 12, unilateral nodular hyperplasia in 4, cystic lesion in 3, and adrenocortical carcinoma in 1 patient. The mean size of all lesions was 5.5 cm. Evaluating the criteria for surgical treatment regarding age of the patients and size of the lesions, 25 patients (48%), including the patient with the adrenocortical carcinoma, were younger than 60 years and had an adrenal lesion exceeding 4 cm in size. During postoperative follow-up that was available for 39 patients, 3 developed contralateral tumors that were treated by resection in 1 and by close follow-up in 2.

CONCLUSIONS

Size should not be the sole criterion; treatment should be tailored to the individual patient. Especially in patients younger than 60 years with an adrenal lesion exceeding 4 cm in size, an adrenalectomy, predominantly via an endoscopic approach, should be carried out, because a repeated and life-long close follow-up of an anxious patient who has been informed of the diagnosis will in some cases exceed the cost of a single endoscopic operation.