The Adrenal Pheochromocytoma Cell Line PC12 Efficiently Promotes the Regeneration Capability of Adipose Tissue-Derived Mesenchymal Stem Cells in Myogenesis: A Particular Approach to Improving Skeletal Muscle Cell Regeneration.

Background: Researchers are looking for a way to improve the myogenic differentiation of stem cells. Adipose-derived stem cells (ADSCs), known for their multipotency and regenerative capabilities, have been extensively studied for their therapeutic potential. Meanwhile, PC12 cells, derived from rat pheochromocytoma, have been found pivotal in neuroscience research, particularly as a neuronal model system. The current study investigated the effect of the PC12 adrenal pheochromocytoma cell line on the myogenic differentiation of ADSCs. Methods: This experimental study was conducted during 2019-2022 (Ahvaz, Iran). Differentiation of ADSCs was induced by using 3 µg/mL 5-azacytidine for 24 hours. Then, the culture media was changed with Dulbecco's Modified Eagle-High Glucose (DMEM-HG) containing 5% horse serum (HS) and kept for 7 days. Different percentages of differentiated ADSCs and PC12 (100:0, 70:30, 50:50, 30:70) were cocultured for 7 days in DMEM-HG containing 5% HS. PC12 was labeled with cell tracker C7000. The real-time polymerase chain reaction and Western blotting techniques were utilized to assess gene and protein expression. All experiments were repeated three times. Data were analyzed using GraphPad Prism 8.0.2 software with a one-way analysis of variance. P<0.05 was considered statistically significant. Results: PC12 visualization confirmed the accuracy of the co-culture process. The differentiated cells showed an aligned, multinucleated shape. The differentiated ADSCs revealed significantly elevated levels of Myh1, Myh2, and Chrn-α1 gene expression compared with undifferentiated ADSCs (P<0.0001). The ADSCs cocultured with PC12 cells showed significantly higher Myh1, Myh2, and Chrn-α1 gene expression than differentiated ADSCs (P<0.001). ADSCs cocultured with 50% PC12 revealed significantly higher MYH and nAchR protein expression than the differentiated group (P<0.01 and P<0.001). Conclusion: Coculturing PC12 cells and ADSCs improves the efficiency of myogenic differentiation. However, the effectiveness of myogenic differentiation depends on the proportions of administered PC12 cells.

Prevention and management of hypertensive crises in children with pheochromocytoma and paraganglioma.

Hypertensive crises in pediatric patients are rare conditions. However, determining their precise prevalence is more challenging than in adults due to the heterogeneity in the definition itself. These crises frequently occur without a prior diagnosis of hypertension and may indicate an underlying cause of secondary hypertension, including pheochromocytoma/paraganglioma (PPGL). The mechanisms of hypertensive crises in the pediatric population with PPGL are directly related to different types of catecholamine excess. Noradrenergic tumors typically present with sustained hypertension due to their predominant action on α1-adrenoceptors in the vasculature. Conversely, adrenergic tumors, through epinephrine binding to ß2-adrenoceptors in addition to stimulation of α1- and α2-adrenoceptors, more frequently cause paroxysmal hypertension. Furthermore, the biochemical phenotype also reflects the tumor localization and the presence of a genetic mutation. Recent evidence suggests that more than 80% of PPGL in pediatric cases have a hereditary background. PPGL susceptibility mutations are categorized into three clusters; mutations in cluster 1 are more frequently associated with a noradrenergic phenotype, whereas those in cluster 2 are associated with an adrenergic phenotype. Consequently, the treatment of hypertensive crises in pediatric patients with PPGL, reflecting the underlying pathophysiology, requires first-line therapy with alpha-blockers, potentially in combination with beta-blockers only in the case of tachyarrhythmia after adequate alpha-blockade. The route of administration for treatment depends on the context, such as intraoperative or pre-surgical settings, and whether it presents as a hypertensive emergency (elevated blood pressure with acute target organ damage), where intravenous administration of antihypertensive drugs is mandatory. Conversely, in cases of hypertensive urgency, if children can tolerate oral therapy, intravenous administration may initially be avoided. However, managing these cases is complex and requires careful consideration of the selection and timing of therapy administration, particularly in pediatric patients. Therefore, facing these conditions in tertiary care centers through interdisciplinary collaboration is advisable to optimize therapeutic outcomes.

Clinical Review: The Approach to the Evaluation and Management of Bilateral Adrenal Masses.

OBJECTIVE: This white paper provides practical guidance for clinicians encountering bilateral adrenal masses. METHODS: A case-based approach to the evaluation and management of bilateral adrenal masses. Specific clinical scenarios presented here include cases of bilateral adrenal adenomas, hemorrhage, pheochromocytomas, metastatic disease, myelolipomas, as well as primary bilateral macronodular adrenal hyperplasia. RESULTS: Bilateral adrenal masses represent approximately 10% to 20% of incidentally discovered adrenal masses. The general approach to the evaluation and management of bilateral adrenal masses follows the same protocol as the evaluation of unilateral adrenal masses, determined based on the patient's clinical history and examination as well as the imaging characteristics of each lesion, whether the lesions could represent a malignancy, demonstrate hormone excess, or possibly represent a familial syndrome. Furthermore, there are features unique to bilateral adrenal masses that must be considered, including the differential diagnosis, the evaluation, and the management depending on the etiology. Therefore, considerations for the optimal imaging modality, treatment (medical vs surgical therapy), and surveillance are included. These recommendations were developed through careful examination of existing published studies as well as expert clinical opinion consensus. CONCLUSION: The evaluation and management of bilateral adrenal masses require a comprehensive systematic approach which includes the assessment and interpretation of the patient's clinical history, physical examination, dynamic hormone evaluation, and imaging modalities to determine the key radiographic features of each adrenal nodule. In addition, familial syndromes should be considered. Any final treatment options and approaches should always be considered individually.

SDHA-related phaeochromocytoma and paraganglioma: review and clinical management.

Phaeochromocytomas and paragangliomas (collectively termed PPGL) are rare yet highly heritable neuroendocrine tumours, with over one-third of cases associated with germline pathogenic variants (PVs) in numerous genes. PVs in the succinate dehydrogenase subunit-A gene (SDHA) were initially implicated in hereditary PPGL in 2010, and SDHA has since become an important susceptibility gene accounting for up to 2.8% of cases. However, it remains poorly understood, particularly regarding the clinical nature of SDHA PPGL, rates of recurrence and metastasis, and the nature of metastatic disease. We present a narrative review of SDHA-related PPGL, covering pathophysiology, relevance to current clinical practice, and considerations for clinical genetics. We analyse a pool of 107 previously reported cases of SDHA-associated PPGL to highlight the spectrum of SDHA-related PPGL. Our analysis demonstrates that SDHA PPGL occurs across a wide age range (11-81 years) and affects men and women equally. SDHA PPGL typically presents as single tumours (91%), usually occurring in the head and neck (46%) or abdomen (43%, including 15% with phaeochromocytomas). Metastatic disease was reported in 25.5% of cases, with bone (82%) and lymph nodes (71%) being the most common sites of metastasis, often identified many years after the initial diagnosis. A family history of SDHA-related neoplasia was rare, reported in only 4% of cases. Understanding the clinical nature and risks associated with SDHA PVs is essential for facilitating the optimal management of patients and their families.

Metastatic pheochromocytoma and paraganglioma: Integrating tumor biology in clinical practice.

Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors derived from chromaffin cells in the autonomic nervous system. Depending on their location, these tumors are capable of excessive catecholamine production, which may lead to uncontrolled hypertension and other life-threatening complications. They are associated with a significant risk of metastatic disease and are often caused by an inherited germline mutation. Although surgery can cure localized disease and lead to remission, treatments for metastatic PPGL (mPPGL)-including chemotherapy, radiopharmaceutical agents, multikinase inhibitors, and immunotherapy used alone or in combination- aim to control tumor growth and limit organ damage. Substantial advances have been made in understanding hereditary and somatic molecular signaling pathways that play a role in tumor growth and metastasis. Treatment options for metastatic disease are rapidly evolving, and this paper aims to provide a brief overview of the management of mPPGL with a focus on therapy options.

[Diagnosis and management of patients with pheochromocytoma/paraganglioma: Consensus of experts of the Russian Medical Society for Arterial Hypertension and the Multidisciplinary Group for the Diagnosis and Treatment of Neuroendocrine Tumors].

The understanding of the nature of catecholamine-secreting tumors has changed significantly in recent years, affecting terminology and classification. Phaeochromocytoma/paraganglioma (PCC/PG) is a rare neuroendocrine tumor from chromaffin tissue that produces and secretes catecholamines. The incidence of PCC/PG is relatively low, with 2-8 cases per 1 million population per year; among patients with arterial hypertension, their prevalence is 0.2-0.6%. However, delayed diagnosis of PCC/PG is associated with a high risk of cardiovascular complications and a high mortality rate. The consensus presents the clinical manifestations of the disease with an emphasis on the course of arterial hypertension as the most common symptom in PCC/PG; modern ideas about the features of diagnosis, aspects of preoperative preparation, treatment, and follow-up of patients with PCC/PG are considered.

Adrenal Pathologies.

Adrenal pathologies have variable clinical presentations and primary care providers should be aware of common and serious adrenal disorders. All adrenal masses require evaluation for malignancy, whether primary or metastatic, and all masses require evaluation for inappropriate hormonal secretion. In the event of adrenal insufficiency, the etiology of cortisol inadequacy must be identified and appropriately treated to prevent life-threatening complications.

Multiple Endocrine Neoplasia Type 1, Type 2A, and Type 2B.

Multiple endocrine neoplasia type 1 is a rare genetic neuroendocrine syndrome caused by over 1500 different germline mutations. It can cause 20 different endocrine tumors affecting primarily the parathyroid glands, gastroenteropancreatic tract, and the anterior pituitary gland. Multiple endocrine neoplasia type 2A (MEN2A) and Multiple endocrine neoplasia type 2B (MEN2B) are autosomal dominant genetic syndromes because of a germline variant in the 'rearranged during transfection' (RET) proto-oncogene. There are common RET mutations causing receptor hyperactivation and induction of downstream signals that cause oncogenesis. Common conditions with MEN2A are medullary thyroid cancer (MTC), pheochromocytoma, and primary hyperparathyroidism. Common conditions with MEN2B include MTC, pheochromocytomas, and benign ganglioneuromas.

Management of metastatic pheochromocytomas and paragangliomas: when and what.

Recently, the treatment landscape for metastatic pheochromocytomas and paragangliomas (MPPGL) has seen both progress and setbacks. We provide an up-to-date review of the multimodality management of MPPGL and discuss novel opportunities and current challenges in the treatment landscape. Given the unique clinical presentation of MPPGL, we discuss the management of hormone-related clinical sequelae and traditional modalities of therapy. Advances in the understanding of the molecular biology of these diverse tumors have enabled novel strategies such as augmenting DNA damage by targeted delivery of radionuclides such as 131I and 177Lu, abrogating tumor angiogenesis, hypoxia resistance, and DNA damage repair. Despite progress, we address the significant challenges still faced by patients and researchers engaged in efforts to improve outcomes in these rare cancers.

Management of Pheochromocytomas and Paragangliomas.

Pheochromocytomas and paragangliomas are distinctive neuroendocrine tumors which frequently produce excess catecholamines with resultant cardiovascular morbidity. These tumors have a strong genetic component, with up to 40% linked to hereditary pathogenic variants; therefore, germline genetic testing is recommended for all patients. Surgical resection offers the only potential cure in the case of localized disease. Given the potential for catecholaminergic crises, appropriate perioperative management is crucial, and all patients should undergo alpha-adrenergic blockade before resection. Therapeutic options for metastatic disease are limited and include surgical debulking, radiopharmaceutical therapies, and conventional chemotherapy.

[Adrenal tumors: current standards in clinical management]. / Nebennierentumoren ­ aktuelle Standards im klinischen Management.

Adrenal tumors are among the most common tumors in humans. They are most frequently discovered incidentally during abdominal imaging for other reasons or due to clinical symptoms (e.g. Conn's or Cushing's syndrome, pheochromocytoma or androgen excess). Although over 80% of adrenal tumors are benign, in cases of hormone excess, they are associated with significantly increased morbidity. In highly malignant adrenocortical carcinoma (ACC), early diagnosis is of particular prognostic relevance. Therefore, this review presents the diagnostic procedure for what are referred to as adrenal incidentalomas and provide recommendations for the management of ACC and pheochromocytomas/paragangliomas (PPGL). In primary diagnosis, sufficient hormone diagnostics is required for all adrenal tumors, as this is the only way to identify all patients with relevant hormone excess. Imaging has increasingly improved in recent years and allows a reliable assessment of the tumor's malignancy in most cases. Imaging of first choice is unenhanced computed tomography (CT), while magnetic resonance imaging (MRI) and fluorodeoxyglucose-18 positron emission tomography (FDG-PET/CT) are reserved for special situations, as published evidence on these procedures is more limited. The treatment of ACC and PPGL is complex and is carried out on an interdisciplinary basis at specialized centers. In the case of localized disease, surgery is the only curative treatment option. There are now clear recommendations for individualized adjuvant therapy for ACC. In metastatic disease, mitotane with or without platinum-containing chemotherapy is the standard. Other lines of therapy should be discussed with a reference center. Over 35% of PPGL have a germline mutation; therefore, genetic testing should be offered. In metastatic PPGL, an individual decision is required between active surveillance, radionuclide therapy, sunitinib or chemotherapy.

Adolescent- and adult-onset neuroblastic tumor: A retrospective multicenter observational study of patients diagnosed in France between 2000 and 2020.

BACKGROUND: Adult- and adolescent-onset neuroblastomas are rare, with no established therapy. In addition, rare pheochromocytomas may harbor neuroblastic components. This study was designed to collect epidemiological, diagnostic and therapeutic data in order to better define the characteristics of malignant peripheral neuroblastic tumors (MPNT) and composite pheochromocytomas (CP) with MPNT. PROCEDURE: Fifty-nine adults and adolescents (aged over 15 years) diagnosed with a peripheral or composite neuroblastic tumor, who were treated in one of 17 institutions between 2000 and 2020, were retrospectively studied. RESULTS: Eighteen patients with neuroblastoma (NB) or ganglioneuroblastoma (GNB) had locoregional disease, and 28 patients had metastatic stage 4 NB. Among the 13 patients with CP, 12 had locoregional disease. Fifty-eight percent of the population were adolescents and young adults under 24 years of age. The probability of 5-year event-free survival (EFS) was 40% (confidence interval: 27%-53%). CONCLUSIONS: Outcomes were better for patients with localized tumor than for patients with metastases. For patients with localized tumor, in terms of survival, surgical treatment was the best therapeutic option. Multimodal treatment with chemotherapy, surgery, radiotherapy, and immunotherapy-based maintenance allowed long-term survival for some patients. Adolescent- and adult-onset neuroblastoma appeared to have specific characteristics associated with poorer outcomes compared to pediatric neuroblastoma. Nevertheless, complete disease control improved survival. The presence of a neuroblastic component in pheochromocytoma should be considered when making therapeutic management decisions. The development of specific tools/resources (Tumor Referral Board, Registry, biology, and trials with new agents or strategies) may help to improve outcomes for patients.

Endocrine Fever.

Fever is usually thought to be of an infectious or inflammatory etiology. In this brief communication, we explore the multifaceted connections between fever and endocrine dysfunction. Impaired resistance to infection often leads to fever in conditions like diabetes and Cushing's syndrome. Additionally, several endocrine disorders, including hyperthyroidism, subacute thyroiditis, carcinoid syndrome, and pheochromocytoma, can manifest as fever. Furthermore, fever can be an adverse effect of various endocrine treatments, such as bisphosphonates and antithyroid drugs. We refer to these scenarios as 'endocrine fever.' Increased awareness of these clinical associations can aid in prompt diagnosis and management of these conditions.

The Immune Landscape of Pheochromocytoma and Paraganglioma: Current Advances and Perspectives.

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors derived from neural crest cells from adrenal medullary chromaffin tissues and extra-adrenal paraganglia, respectively. Although the current treatment for PPGLs is surgery, optimal treatment options for advanced and metastatic cases have been limited. Hence, understanding the role of the immune system in PPGL tumorigenesis can provide essential knowledge for the development of better therapeutic and tumor management strategies, especially for those with advanced and metastatic PPGLs. The first part of this review outlines the fundamental principles of the immune system and tumor microenvironment, and their role in cancer immunoediting, particularly emphasizing PPGLs. We focus on how the unique pathophysiology of PPGLs, such as their high molecular, biochemical, and imaging heterogeneity and production of several oncometabolites, creates a tumor-specific microenvironment and immunologically "cold" tumors. Thereafter, we discuss recently published studies related to the reclustering of PPGLs based on their immune signature. The second part of this review discusses future perspectives in PPGL management, including immunodiagnostic and promising immunotherapeutic approaches for converting "cold" tumors into immunologically active or "hot" tumors known for their better immunotherapy response and patient outcomes. Special emphasis is placed on potent immune-related imaging strategies and immune signatures that could be used for the reclassification, prognostication, and management of these tumors to improve patient care and prognosis. Furthermore, we introduce currently available immunotherapies and their possible combinations with other available therapies as an emerging treatment for PPGLs that targets hostile tumor environments.

Treatment of metastatic paraganglioma: experience of a single center.

PURPOSE: Data regarding treatment options and their efficacy for metastatic paragangliomas (mPPGL) is limited. This study aims to report a single center experience in treating mPPGL, comparing the efficacy and safety of various treatment approaches. METHODS: Retrospective analysis of patients with mPPGL treated at an Endocrinology Department of a cancer institute between January 2000 and October 2022. RESULTS: We analyzed 25 patients with mPPGL, 8 pheochromocytomas and 20 paragangliomas (12% multifocal), followed for a median of 9 [4; 14] years. Surgical approach, aimed at the primary tumor or at debulking of metastases, was the only treatment achieving complete response: 87% in primary tumor and 87.5% with debulking of metastases. These were long-lasting results with a duration of 69 (23.8; 136.8) months in primary tumor removal and 35.1 (15.3; 41) months in metastases debulking. As for other therapeutic approaches, such as radioactive isotopes, tyrosine kinase inhibitors, chemotherapy and external beam radiotherapy, the main outcome was stable disease, with few partial responses. At the last follow-up, 66% of the patients were alive, 15.4% were in remission and 84.6% had stable disease. Median overall survival was 14 years. The 5-year and 10-year survival rates from primary tumor diagnosis were 77.9% and 66.9% respectively, and from metastasis diagnosis were 67.4% and 55.6%, respectively. CONCLUSION: This is the only European single center analysis addressing outcomes of different therapies in mPGL. The results support surgery as a first-line treatment, being the only approach that may achieve complete response with satisfactory and long-lasting results.

Management of phaeochromocytoma and paraganglioma in patients with germline SDHB pathogenic variants: an international expert Consensus statement.

Adult and paediatric patients with pathogenic variants in the gene encoding succinate dehydrogenase (SDH) subunit B (SDHB) often have locally aggressive, recurrent or metastatic phaeochromocytomas and paragangliomas (PPGLs). Furthermore, SDHB PPGLs have the highest rates of disease-specific morbidity and mortality compared with other hereditary PPGLs. PPGLs with SDHB pathogenic variants are often less differentiated and do not produce substantial amounts of catecholamines (in some patients, they produce only dopamine) compared with other hereditary subtypes, which enables these tumours to grow subclinically for a long time. In addition, SDHB pathogenic variants support tumour growth through high levels of the oncometabolite succinate and other mechanisms related to cancer initiation and progression. As a result, pseudohypoxia and upregulation of genes related to the hypoxia signalling pathway occur, promoting the growth, migration, invasiveness and metastasis of cancer cells. These factors, along with a high rate of metastasis, support early surgical intervention and total resection of PPGLs, regardless of the tumour size. The treatment of metastases is challenging and relies on either local or systemic therapies, or sometimes both. This Consensus statement should help guide clinicians in the diagnosis and management of patients with SDHB PPGLs.

Successful treatment of acute respiratory failure following hypertensive crisis in a dog with presumed pheochromocytoma or paraganglioma.

Background: Acute respiratory failure has been reported as one of the manifestations of hypertensive crisis in pheochromocytoma in human medicine. In dogs, no reports have been described as acute respiratory failure following hypertensive crisis. Here, we report the clinical presentation, course, and treatment of acute respiratory failure following the hypertensive crisis in a dog with presumed pheochromocytoma or paraganglioma. Case Description: A 12-year-old neutered male toy poodle was referred for the diagnostic evaluation of a right adrenal gland mass. The dog suddenly exhibited severe dyspnea with abnormal hypertension (systolic blood pressure >200 mmHg) 15 minutes after recovery from the anesthesia for the computed tomography (CT) examination. Pulmonary CT and ultrasonography findings suggested acute onset of severe pulmonary edema. Pulmonary edema was treated with mechanical ventilation (pressure-support ventilation with continuous positive airway pressure) and negative fluid balance after the administration of furosemide. Weaning from mechanical ventilation was successful 24 hours after the onset of respiratory failure. Finally, the dog was discharged 3 days after weaning from ventilation without complications. Conclusion: This report outlines a case of acute respiratory failure following a hypertensive crisis requiring mechanical ventilatory management in a dog. The onset and progression of pulmonary edema were extremely rapid. However, improvement in pulmonary edema was also rapid. Hemodynamic stability, in addition to prompt diagnosis and aggressive therapeutic intervention, including mechanical ventilation, may have contributed to the good prognosis of pulmonary edema following hypertensive crisis in a dog, which we attribute to a catecholamine storm.

Pheochromocytoma and paraganglioma in children and adolescents.

Pheochromocytoma (PPC) and paraganglioma (PGL) are the tumors that rarely occur in the pediatric population (PPGL). Both originate from chromaffin cells, pheochromocytoma is localized in the adrenal gland, whereas paragangliomas are regarded as the tumors present in other localizations, from head to the pelvis. The clinical image is characterized by the presence of the sustained hypertension, headaches, sweating, palpitations. The symptoms are caused by the catecholamine secretion or are related to tumor mass pressure on different organs. The catecholamines and their metabolites levels in urine collection or plasma are necessary for further evaluation of the diagnosis. In pediatric population the tumors occur in multiple familial syndromes such as Multiple Endocrine type 2, Neurofibromatosis type 1, Von Hippel-Lindau syndrome, Familial Paraganglioma syndrome are related to specific mutations (SDHx, RET, VHL, NF1) leading to the characteristic phenotype. The radiological and nuclear imaging are an important part of the examination. Although CT and MR are reported to have overall good sensitivity for the tumor detection, further analysis with nuclear imaging is recommended for the specified diagnosis. Right now 68GA-DOTATATE is regarded as the tracer of choice, leading to the complex evaluation of patients with different mutations and metastatic disease. The treatment of choice is the tumor excision. Also, lately new therapeutic approaches including genetically targeted therapies are under investigation for more complex treatment of tumors with underlying genetic cause or metastatic disease. Long term follow-up after treatment to avoid recurrence or to detect it in early stadium must be performed.

Diagnosis and Management of Pheochromocytomas and Paragangliomas: A Guide for the Clinician.

OBJECTIVE: The aim of this review was to provide a practical approach for clinicians regarding the diagnosis and management of pheochromocytomas and paragangliomas (PPGLs). METHODS: A literature search of PubMed was carried out using key words, including pheochromocytoma, paraganglioma, treatment, diagnosis, screening, and management. The discussion of diagnosis and management of PPGL is based on the evidence available from prospective studies when available and mostly from cohort studies, cross-sectional studies, and expert consensus. RESULTS: PPGL are neuroendocrine tumors arising from the chromaffin cells of adrenal medulla and sympathetic and parasympathetic ganglia, respectively. PPGL can be localized or metastatic, and they may secrete catecholamines, causing a variety of symptoms and potentially catastrophic and lethal complications if left untreated. The rarity of these tumors along with heterogeneous clinical presentation often poses challenges for the diagnosis and management. PPGL can be associated with several familial syndromes which are important to recognize. CONCLUSION: The last few years have witnessed an exponential growth in the knowledge around PPGL. This review aims at providing a comprehensive discussion of current concepts for clinicians regarding clinical presentation, diagnostic tools, and management strategies for PPGL.

Intratumoral immunotherapy of murine pheochromocytoma shows no age-dependent differences in its efficacy.

Cancer immunotherapy has shown remarkable clinical progress in recent years. Although age is one of the biggest leading risk factors for cancer development and older adults represent a majority of cancer patients, only a few new cancer immunotherapeutic interventions have been preclinically tested in aged animals. Thus, the lack of preclinical studies focused on age-dependent effect during cancer immunotherapy could lead to different therapeutic outcomes in young and aged animals and future modifications of human clinical trials. Here, we compare the efficacy of previously developed and tested intratumoral immunotherapy, based on the combination of polysaccharide mannan, toll-like receptor ligands, and anti-CD40 antibody (MBTA immunotherapy), in young (6 weeks) and aged (71 weeks) mice bearing experimental pheochromocytoma (PHEO). The presented results point out that despite faster growth of PHEO in aged mice MBTA intratumoral immunotherapy is effective approach without age dependence and could be one of the possible therapeutic interventions to enhance immune response to pheochromocytoma and perhaps other tumor types in aged and young hosts.