Phaeochromocytomas as a cause of hypotension

Adrenal pheochromocytoma impacts three main pathways: cysteine-methionine, pyrimidine, and tyrosine metabolism

Pheochromocytomas and paragangliomas (PPGLs) cause symptoms by altering the circulation levels of catecholamines and peptide hormones. Currently, the diagnosis of PPGLs relies on diagnostic imaging and the detection of catecholamines. In this study, we used ultra-performance liquid chromatography (UPLC)/quadrupole time-of-flight mass spectrometry (Q-TOF MS) analysis to identify and measure the perioperative differential metabolites in the plasma of adrenal pheochromocytoma patients. We identified differentially expressed genes by comparing the transcriptomic data of pheochromocytoma with the normal adrenal medulla. Through conducting two steps of metabolomics analysis, we identified 111 differential metabolites between the healthy group and the patient group, among which 53 metabolites were validated. By integrating the information of differential metabolites and differentially expressed genes, we inferred that the cysteine-methionine, pyrimidine, and tyrosine metabolism pathways were the three main metabolic pathways altered by the neoplasm. The analysis of transcription levels revealed that the tyrosine and cysteine-methionine metabolism pathways were downregulated in pheochromocytoma, whereas the pyrimidine pathway showed no significant difference. Finally, we developed an optimized diagnostic model of two metabolites, L-dihydroorotic acid and vanylglycol. Our results for these metabolites suggest that they may serve as potential clinical biomarkers and can be used to supplement and improve the diagnosis of pheochromocytoma.

Catecholamine-induced hypertensive crises: current insights and management

Phaeochromocytomas and paragangliomas (PPGLs) release catecholamines leading to catecholamine-induced hypertensive (CIH) crises, with blood pressure greater than or equal to 180/120 mm Hg. CIH crises can be complicated by tachyarrhythmias, hypotension, or life-threatening target organ damage while treatment remains undefined, often requiring co-management between endocrinologists and cardiologists. Furthermore, biochemical diagnosis of a PPGL as a cause of a CIH crisis can be difficult to identify or confounded by comorbid conditions, potentially resulting in misdiagnosis. Here, we combine relevant evidence, 60 years of collective clinical experience, insights derived from assessing over 2600 patients with PPGL, and supplementary outcomes from 100 patients (treated at the National Institutes of Health) with a CIH crisis to inform diagnosis and treatment of CIH crises. Recognising that disparities exist between availability, cost, and familiarity of various agents, flexible approaches are delineated allowing for customisation, given institutional availability and provider preference. A CIH crisis and its complications are readily treatable with available drugs, with effective intervention defining an avenue for mitigating consequent morbidity and mortality in patients with PPGL.

Pheochromocytoma/paraganglioma-associated cardiomyopathy

Pheochromocytoma/paraganglioma (PPGL) are neuroendocrine tumors that frequently produce and release catecholamines. Catecholamine excess can manifest in several cardiovascular syndromes, including cardiomyopathy. PPGL-induced cardiomyopathies occur in up to 11% of cases and are most often associated with an adrenal pheochromocytoma (90%) and rarely with a paraganglioma derived from the sympathetic ganglia (10%). PPGL-associated cardiomyopathies can be chronic or acute, with takotsubo cardiomyopathy being the most often reported. These two types of PPGL-induced cardiomyopathy seem to have different pathophysiological backgrounds. Acute catecholaminergic stress inundates myocardial β-adrenoceptors and leads to left ventricle stunning and slight histological apoptosis. In chronic cardiomyopathy, prolonged catecholamine exposure leads to extended myocardial fibrosis, inflammation, and necrosis, and ultimately it causes dilated cardiomyopathy with a low ejection fraction. Sometimes, especially in cases associated with hypertension, hypertrophic cardiomyopathy can develop. The prognosis appears to be worse in chronic cases with a higher hospital mortality rate, higher cardiogenic shock rate at initial presentation, and lower left ventricular recovery rate after surgery. Therefore, establishing the correct diagnosis at an early stage of a PPGL is essential. This mini-review summarizes current data on pathophysiological pathways of cardiac damage caused by catecholamines, the clinical presentation of PPGL-induced cardiomyopathies, and discusses treatment options.

Predictors of prolonged hypotension requiring vasopressor support after resection of pheochromocytoma and paraganglioma

OBJECTIVE

Prolonged hypotension is a common complication after resection of pheochromocytoma (PCC) or paraganglioma (PGL). The objective of our study was to identify preoperative or intraoperative clinical factors that can predict prolonged hypotension after PCC/PGL resection.

PATIENTS AND METHODS

A total of 414 patients who underwent resection of PCC or PGL at our institution between January 2013 and January 2020 were included. Patients were divided into two groups according to whether or not vasopressor support was required postoperatively. Associations between preoperative and intraoperative variables and prolonged hypotension were evaluated.

RESULTS

Two hundred and one (48.6%) patients had postoperative hypotension that required vasopressor support with a median duration of 20 h. Multivariable analysis demonstrated that increased 24-h urinary norepinephrine (NE) levels (odds ratio [OR] = 1.091, 95% confidence interval [CI]: 1.052-1.132, p < .001), longer operative time (OR = 1.008, CI: 1.004-1.011, p < .001) and lower preoperative phenoxybenzamine dose (OR = 0.336, CI: 0.150-0.753, p = .008) were predictors of prolonged hypotension. Moreover, operative time, body mass index, 24-h urinary level of NE and preoperative phenoxybenzamine dose were significantly correlated with the duration of postoperative vasopressor support.

CONCLUSIONS

Increased urine NE level, longer operative time and lower preoperative phenoxybenzamine dose were predictors of prolonged hypotension requiring vasopressor support. Clinicians can identify these factors to manage their patients better and prevent severe complications.

Johnson and Johnson COVID-19 Vaccination Triggering Pheochromocytoma Multisystem Crisis

Pheochromocytomas are rare tumors that may have variable presentations. The presentation may depend on the type of catecholamine secreted, whether there is a paraneoplastic syndrome or not, or some other factor which may not be well understood. One rare presentation is a pheochromocytoma multisystem crisis. Many of these tumors are asymptomatic and found incidentally, but some can be triggered after being previously dormant. In this case report, we describe the first case of pheochromocytoma multisystem crisis triggered by the Johnson and Johnson (J&J) coronavirus disease 2019 (COVID-19) vaccine. We describe a case of a 63-year-old Caucasian male who presented with intractable nausea, vomiting, dyspnea, watery diarrhea, chills, sweats, and heavy chest pain starting one day status post J&J COVID-19 vaccination. He had no symptoms prior to this and no significant past medical history besides daily marijuana use. During his hospital stay, he had persistent high fevers, respiratory failure, cardiogenic shock, cardiomyopathy, and labile blood pressure measurements. After a retroperitoneal ultrasound, he was found to have a 7 cm mass in the right adrenal gland with elevated chromogranin A, urine vanillylmandelic acid (VMA), and urinary 24-hour metanephrines to confirm the diagnosis of a pheochromocytoma.

Pathophysiology and Acute Management of Tachyarrhythmias in Pheochromocytoma: JACC Review Topic of the Week

Pheochromocytomas, arising from chromaffin cells, produce catecholamines, epinephrine and norepinephrine. The tumor biochemical phenotype is defined by which of these exerts the greatest influence on the cardiovascular system when released into circulation in high amounts. Action on the heart and vasculature can cause potentially lethal arrhythmias, often in the setting of comorbid blood pressure derangements. In a review of electrocardiograms obtained on pheochromocytoma patients (n = 650) treated at our institution over the last decade, severe and refractory sinus tachycardia, atrial fibrillation, and ventricular tachycardia were found to be the most common or life-threatening catecholamine-induced tachyarrhythmias. These arrhythmias, arising from catecholamine excess rather than from a primary electrophysiologic substrate, require special considerations for treatment and complication avoidance. Understanding the synthesis and release of catecholamines, the adrenoceptors catecholamines bind to, and the cardiac and vascular response to epinephrine and norepinephrine underlies optimal management in catecholamine-induced tachyarrhythmias.

Management of 3 Cases of Pheochromocytoma During the COVID-19 Pandemic in New York City: Lessons Learned

The COVID-19 crisis placed a pause on surgical management of nonemergency cases of pheochromocytoma, and it was essential for endocrinologists to provide both resourceful and safe care. At the Mount Sinai Hospital in New York City during the peak of the pandemic, we encountered 3 patients with pheochromocytoma and mild symptoms that were medically managed for a prolonged period of time (7-18 weeks) prior to adrenalectomy. Patients were monitored biweekly via telemedicine, and antihypertensive medications were adjusted according to signs, symptoms, and adrenergic profiles. These cases demonstrate that prolonged medical management prior to surgery is feasible and effective in pheochromocytoma patients with mild symptoms and well-controlled blood pressures.

Adrenal Incidentaloma

An adrenal incidentaloma is now established as a common endocrine diagnosis that requires a multidisciplinary approach for effective management. The majority of patients can be reassured and discharged, but a personalized approach based upon image analysis, endocrine workup, and clinical symptoms and signs are required in every case. Adrenocortical carcinoma remains a real concern but is restricted to <2% of all cases. Functional adrenal incidentaloma lesions are commoner (but still probably <10% of total) and the greatest challenge remains the diagnosis and optimum management of autonomous cortisol secretion. Modern-day surgery has improved outcomes and novel radiological and urinary biomarkers will improve early detection and patient stratification in future years to come.

Fluctuation of Blood Pressure in a Patient With Pheochromocytoma

Treatment with a combination of norepinephrine and doxazosin was effective in a patient with pheochromocytoma who had blood pressure fluctuation, hypotension, and recurrent syncope. After adrenalectomy, his blood pressure, heart rate, and plasma levels of catecholamines remained normal and stable without any medication. (Level of Difficulty: Beginner.)

Pheochromocytoma/paraganglioma: recent updates in genetics, biochemistry, immunohistochemistry, metabolomics, imaging and therapeutic options

Pheochromocytomas and paragangliomas (PPGLs), rare chromaffin/neural crest cell tumors, are commonly benign in their clinical presentation. However, there are a number of cases presenting as metastatic and their diagnosis and management becomes a dilemma because of their rarity. PPGLs are constantly evolving entities in the field of endocrinology brought about by endless research and discoveries, especially in genetics. Throughout the years, our knowledge and perception of these tumors and their genetic background has greatly expanded and changed, and each new discovery leads to advancement in the diagnosis, treatment and follow-up of PPGLs. In this review, we discuss the recent updates in the genetics, biochemistry, immunohistochemistry, metabolomics, imaging and treatment options of PPGLs.

The Highs and Lows of an Unknown Pheochromocytoma in an Elderly Patient

Pheochromocytomas are rare catecholamine producing neuroendocrine tumors. The incidence of these tumors is estimated to affect 0.8 per 100,000 person-years and is most common in the fourth to fifth decade of life with equal prevalence in men and women. We describe a case of an 84-year-old male who presented with cycling episodes of severe hypertension and hypotension after an elective cardiac catheterization. Workup of the labile blood pressure revealed a large suprarenal mass and free serum metanephrines (MN) 104 nmol/L (reference range 0.0-0.49 nmol/L) and normetanephrines (NMN) of 24 nmol/L (reference range 0.0-0.89 nmol/L), confirming the diagnosis of a pheochromocytoma. The patient's labile blood pressure was a challenge to manage medically and improved only after aggressive hydration and an alpha-adrenergic antagonist. Of note, this is the second eldest patient known to be published to date with a pheochromocytoma.

PRECISION MEDICINE: AN UPDATE ON GENOTYPE/BIOCHEMICAL PHENOTYPE RELATIONSHIPS IN PHEOCHROMOCYTOMA/PARAGANGLIOMA PATIENTS

OBJECTIVE

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors known to produce and secrete high levels of circulating catecholamines and their metabolites. The biochemical characteristics of these tumors can be used to divide them into three major phenotypes. The adrenergic, noradrenergic and dopaminergic phenotypes are defined by predominant elevations in epinephrine and metanephrine, norepinephrine and normetanephrine, and dopamine and 3-methoxytyramine, respectively. There are over 15 well-identified tumor-susceptibility genes responsible for approximately 40% of the cases. The objective of this review article is to outline specific genotype/biochemical phenotype relationships.

METHODS

Literature review.

RESULTS

None.

CONCLUSION

Biochemical phenotype of PPGL is determined by the underlying genetic mutation and the associated molecular pathway. Identification of genotype/biochemical relationships is valuable in prioritizing testing for specific genes, making treatment decisions and monitoring disease progression.

ABBREVIATIONS

3-MT = 3-methoxytyramine; EPAS1 = endothelial pas domain protein 1; FH = fumarate hydratase; HIF2A = hypoxia inducible factor type 2A; MEN2 = multiple endocrine neoplasia type 2; NF1 = neurofibromatosis type 1; PNMT = phenylethanolamine N-methyltransferase; PPGL = pheochromocytoma and paraganglioma; RET = rearranged during transfection; SDH = succinate dehydrogenase; SDHAF2 = succinate dehydrogenase complex assembly factor 2; TCA = tricarboxylic acid; TH = tyrosine hydroxylase; TMEM127 = transmembrane protein 127; VHL = von Hippel-Lindau.

Ventricular Rhythm and Hypotension in a Patient with Pheochromocytoma-induced Myocardial Damage and Reverse Takotsubo Cardiomyopathy

A 33-year-old woman experienced near-syncope at a hospital. Electrocardiography revealed an intermittent ventricular rhythm. The echocardiogram at admission indicated mild hypokinesis and severe diffuse hypokinesis with reverse takotsubo cardiomyopathy on the following day. The patient experienced abdominal pain on the admission day, and computed tomography identified a large left adrenal mass. Her catecholamine levels increased remarkably on the third day. The wall motion improved on the twelfth day. The tumor was successfully resected and the patient was diagnosed with an ectopic pheochromocytoma. The ventricular rhythm with myocardial damage and hypotension induced by the reverse takotsubo cardiomyopathy masked the characteristic symptoms of pheochromocytoma.

Anti-hypertensive treatment in pheochromocytoma and paraganglioma: current management and therapeutic features

Pheochromocytoma (PH) and paraganglioma (PG) are neuroendocrine neoplasms arising from chromaffin cells of the adrenal medulla and the sympathetic ganglia, respectively. Although are unusual cause of hypertension (HT) accounting for at most 0.1-0.2 % of cases, they may lead to severe and potentially lethal hypertensive crisis due to the effects of the released catecholamines. However, both PH and PG may be asymptomatic as ~30 % of subjects are normotensive or have orthostatic hypotension and in these cases the 24 h ambulatory blood pressure (BP) monitoring is an important toll to diagnose and treat HT. HT treatment may be difficult when PH or PG occurs in pregnancy or in the elderly subjects and in these cases a multidisciplinary team is required. When surgical excision is mandatory the perioperative management requires the administration of selective α1-adrenergic blocking agents (i.e., doxazosin, prazosin or terazosin) followed by a β-adrenergic blockade (i.e., propranolol, atenolol). This latter should never be started first because blockade of vasodilatory peripheral β-adrenergic receptors with unopposed α-adrenergic receptor stimulation can lead to a further elevation of BP. Although labetalol is traditionally considered the ideal agent due to its α- and β-adrenergic antagonism, experimental studies do not support its use in this clinical setting. As second regimen, the administration of vasodilators as calcium channel blockers (i.e., nicardipine, nifedipine) may be required to control BP. Oral and sublingual short-acting nifedipine are potentially dangerous in patients with hypertensive emergencies and are not recommend. The latest evidences into the diagnosis and treatment of hypertensive crisis due to PH and PG are reviewed here.

Cardiovascular manifestations of phaeochromocytoma

Clinical expression of phaeochromocytoma may involve numerous cardiovascular manifestations, but usually presents as sustained or paroxysmal hypertension associated with other signs and symptoms of catecholamine excess. Most of the life-threatening cardiovascular manifestations of phaeochromocytoma, such as hypertensive emergencies, result from a rapid and massive release of catecholamines from the tumour. More rarely, patients with phaeochromocytoma present with low blood pressure or even shock that may then precede multisystem crisis. Sinus tachycardia, with palpitations as the presenting symptom, is the most prevalent abnormality of cardiac rhythm in phaeochromocytoma, but tumours can also be associated with more serious ventricular arrhythmias or conduction disturbances. Reversible dilated or hypertrophic cardiomyopathy are well established cardiac manifestations of phaeochromocytoma, with more recent attention to an increasing number of cases with Takotsubo cardiomyopathy. This review provides an update on the cause, clinical presentation and treatment of the cardiovascular manifestations of phaeochromocytoma. As the cardiovascular complications of phaeochromocytoma can be life-threatening, all patients who present with manifestations that even remotely suggest excessive catecholamine secretion should be screened for the disease.

Unpredicted tachycardia and hypotension in a patient with medullary thyroid cancer and undiagnosed pheochromocytoma: A case report

A 35 year old woman with hypercalcitoninemia was scheduled for an operation to treat her medullary thyroid cancer (MTC). TIVA with propofol and remifentanil was planned, and about 3 minutes after the infusion of anesthetics, her heart rate was suddenly elevated to 180/min and the systolic blood pressure was lowered to nearly 50 mmHg. The blood pressure returned to normal after the injection of phenylephrine 100 microgram and a rapid infusion of 700 ml crystalloid solution. After the operation, bilateral pheochromocytoma and a RET proto-oncogene mutation related with multiple endocrine neoplasia 2A (MEN-2A) were found. Patients with MTC can present with peripheral vasodilation and relative hypovolemia that are related with hypercalcitoninemia. Patients with MEN-2A can be anesthetized for a MTC operation without the appropriate preparation for their pheochromocytoma. Therefore, we suggest that patients with MTC and hypercalcitoninemia should be cautiously anesthetized with TIVA. They also should be screened for pheochromocytoma and the RET proto-oncogene mutation to prevent deleterious hemodynamic events during anesthesia.

Pheochromocytoma presenting as acute myocarditis with cardiogenic shock in two cases

Pheochromocytoma is a rare, catecholamine-secreting tumor. The classic symptoms are headache, diaphoresis, and tachycardia with paroxysmal hypertension. Other less common cardio-vascular manifestations, such as arrhythmias, angina pectoris, acute myocardial infarction, dilated cardiomyopathy, acute heart failure, and cardiogenic shock, have occasionally been reported. Here, we report two middle-aged men with acute myocarditis and cardiogenic shock, who needed an intra-aortic balloon pump and extra-corporeal membrane oxygenation for life support. They were diagnosed with pheochromocytoma and underwent laparoscopic adrenectomy that restored cardiac function. These cases illustrate diagnostic and management considerations in pheochromocytoma complicated by acute myocarditis and cardiogenic shock.

Emergencies caused by pheochromocytoma, neuroblastoma, or ganglioneuroma

Pheochromocytoma may lead to important emergency situations, ranging from cardiovascular emergencies to acute abdomen and multiorgan failure. It is vital to think about this disease in any emergency situation when conventional therapy fails to achieve control or symptoms occur that do not fit the initial diagnosis. The importance of keeping this diagnosis in minds is underscored by the fact that, in 50% of pheochromocytoma patients, the diagnosis is initially overlooked. Two other tumors of the sympathetic nervous system, neuroblastoma and ganglioneuroma, are less commonly associated with emergency conditions. If they occur, they are often linked to catecholamine excess, paraneoplastic phenomena, or local tumor mass effect.

Adrenergic shock--an overlooked clinical entity?

We report a case of recurrent shock induced by pheochromocytoma in a previously healthy, normotensive patient. We review pathophysiology and clinical features of shock and cardiomyopathy in patients with pheochromocytoma. We discuss diagnostic evaluation and therapy for pheochromocytoma-induced shock.

Pheochromocytoma presenting as recurrent hypotension and syncope

We report a case with pheochromocytoma presenting as recurrent syncope due to hypotension. A 71-year-old man was admitted because of recurrent syncope and paroxysmal hypotension. He was diagnosed as having pheochromocytoma. In spite of a large volume of infusion and insulin therapy, syncope and paroxysmal hypotension continued. We speculated that hypotension was mainly due to vasodilatation caused by excess plasma epinephrine and prescribed a non-selective beta-adrenergic blocker. It stabilized blood pressure and syncope disappeared. The right adrenal tumor was excised and he was discharged in good condition. This case report provides some implications for the management of pheochromocytoma complicated with hypotension.

Pheochromocytoma: a paradigm for catecholamine-mediated hypertension

Transient or permanent hypertension may result from the inappropriate activation of the sympathetic nervous system and/or from chronically elevated levels of circulating catecholamines (epinephrine or norepinephrine). Recent data implicate this high sympathetic tone as a contributing factor to the genesis of essential hypertension in a significant proportion of individuals, and show that it is frequently associated with insulin resistance and cardiovascular comorbidity. Among the several causes of catecholamine-mediated hypertension, pheochromocytoma, although rare, holds a special place and represents a challenging experience for the clinician. Diagnosis and therapy of this remarkable disease will be reviewed here in details, with a special emphasis on recent findings such as the high diagnostic sensitivity of plasma fractionated metanephrines, the better understanding of genetic diseases predisposing to chromaffin tumor development, and the modern management of pheochromocytoma, including the medical preparation before surgery. Other causes of catecholamine excess will be reviewed more briefly.

Epinephrine producing pheochromocytoma. Is the secretory pattern decisive for the clinical manifestation?

Adrenal incidentalomas are becoming a major clinical problem, due to increasingly frequent radiological examinations. We present two cases of patients referred to our department with a finding of an unsuspected adrenal mass. Both of them were normotensive and without symptomatology typical for pheochromocytoma. In one patient we found 20-times higher levels of epinephrine and 3-times higher levels of dopamine in 24-h urine, in the second patient there were 8-times higher levels of epinephrine alone. Norepinephrine in urine, as well as values of all adrenal cortical hormones were normal. The diagnosis of pheochromocytoma was confirmed in both cases by a 123I-metaiodobenzylguanidine (MIBG) scintigraphy. The patients underwent adrenalectomy, which was performed without complications. We conclude that levels of single catecholamines excreted are decisive for the clinical presentation of pheochromocytoma. Epinephrine producing pheochromocytoma is more often oligo- or asymptomatic. We stress the importance of a complete hormonal screening in every case of adrenal incidentaloma, with measuring levels of catecholamines and/or metanephrines.

Circulatory shock

Patients with malignancy may present with acute circulatory compromise requiring ICU monitoring and care. The clinician must be familiar with a multiplicity of acute and chronic medical conditions common to the general population and also with conditions directly related to cancer or therapy thereof.

Phaeochromocytoma with adult respiratory distress syndrome mimicking septicaemic shock

Phaeochromocytomas are rare tumours that most commonly present with chronic sustained hypertension and hypertensive paroxysms or crises. We report a 49-year-old woman with unsuspected phaeochromocytoma who presented with sudden onset of profound hypotension and adult respiratory distress syndrome unresponsive to fluid and inotropic support. This case illustrates the diversity of presentations of phaeochromocytoma, depending on the type and amount of catecholamines secreted.

Surgical treatment of pheochromocytomas

Pheochromocytomas are tumors that develop from chromaffin tissue of the embryonic sympathoadrenal system. These tumors may occur anywhere chromaffin tissue exists but most often develop in the adrenal medulla. Less than 50% of patients are diagnosed with pheochromocytomas while alive, and most of these tumors are found on autopsy. The classic signs and symptoms of pheochromocytomas are headache, perspiration, palpitations, pallor, and paroxysmal hypertension. Elevated levels of vanillylmandelic acid and metanephrines in patients' 24-hour urine collections are the most reliable diagnostic indicators of pheochromocytomas. Most patients with pheochromocytomas can be cured if diagnoses and surgical resections of tumors occur before irreversible cardiovascular disease and end-organ damage from hypertension develop.

Adrenal tumour, congestive heart failure and hemiparesis in an 18-year-old male. A clinical-pathological conference

A case of a young male presenting with mild hypertension, congestive cardiac failure, stroke in the distribution of the left middle cerebral artery and a right suprarenal mass is discussed. Diagnostic and therapeutic strategies are presented.

Twenty-four hour ambulatory blood pressure and heart rate in a patient with a predominantly adrenaline secreting phaeochromocytoma

In this report, we present the symptoms, biochemical investigations, 24 hour ambulatory blood pressure and heart rate recordings in a patient before and following removal of a predominantly adrenaline-secreting phaeochromocytoma. The symptoms were of episodic shaking, faintness, nausea, palpitations, sweating and panic, chest and neck pain with headache, and are consistent with previous reports. Ambulatory blood pressure recording demonstrated that mean daily blood pressure was normal, with normal diurnal variation, and two episodes of severe hypertension and bradycardia coincident with symptoms (MAP 150 mmHg and HR 49 beats/minute, MAP 178 mmHg and HR 29 beats/minute, respectively), not reported in predominantly adrenaline-secreting phaeochromocytoma.