Extraadrenal paragangliomas of the body: imaging features

Paraaortic Extra-Adrenal Paraganglioma: Challenging Robotic Resection

BACKGROUND

Up to 41% of intra- and extra-adrenal paragangliomas are linked to germline mutations with autosomal dominant transmission, which necessitates genetic testing for patients and their relatives.1-4 Certain alterations, such as the succinate dehydrogenase (SDH) subunit B gene mutation, are associated with a significant risk of extra-adrenal, malignant, and metastatic disease forms.4-7 This highlights the need for routine genetic counseling and diligent surveillance, as well as surgeon awareness of hereditary paraganglioma-pheochromocytoma syndrome (HPPS).

METHODS

We present a multimedia article featuring a step-by-step video of a complex retroperitoneal resection, enriched with perioperative management insights.

RESULTS

A 17-year-old female presented with episodes of hypertension, tachycardia, and diffuse diaphoresis. CT revealed a paraaortic mass adjacent to the left renal hilum later confirmed by a SPECT/CT with iodine-123 meta-iodobenzylguanidine.8 Additional imaging with gallium-68 DOTATATE was not performed then due to unknown mutation status. The patient underwent robotic removal of the tumor and adjacent lymph nodes. Pathology confirmed a poorly differentiated paraganglioma with 0/6 lymph node metastases. Genetic tests revealed SDHB gene mutation, indicative of HPPS.9,10 At 12 months, the patient remained disease-free on CT with normalized metanephrines levels and no detectable circulating tumor DNA. Familial screening detected her mother, maternal uncle, and maternal grandfather to be SDHB mutation carriers, although phenotypically silent.

CONCLUSIONS

Robotic-assisted resection can be safe and effective for retroperitoneal malignant paragangliomas. However, management extends beyond surgery and requires cascade genetic testing to address familial risks. Because of the high probability of cancer associated with SDHB mutation, lifelong patient surveillance is imperative.

A Case of Bilateral Carotid Body Tumors

Sporadic bilateral carotid body tumors are a rare paraganglioma of the head and neck that are often asymptomatic and incidentally found during workup for other pathologies. These tumors arise from the chemoreceptor organ located at the carotid bifurcation and can be locally invasive, resulting in the involvement of adjacent neurovascular structures. With the majority of bilateral carotid body tumors having an association with familial syndromes, such as MEN2 or Von Hippel Lindau, the incidence of sporadic bilateral disease is exceedingly rare. In this case report, we report a case of bilateral carotid body tumors in a 54-year-old female with anxiety and tachycardia who underwent MRI and CTA evaluation showing evidence of left greater than right carotid body tumors. The patient was managed operatively in a staged fashion with a resolution of her presenting symptoms and no post-operative morbidity or mortality. Pathologic examination of the bilateral masses confirmed evidence of paraganglioma with immunohistochemical stains showing neoplastic cells positive for synaptophysin, chromogranin, and S100 without lymph node involvement.

The Radiological Assessment of Carotid Space Lesions: A Case Series

Carotid space lesions present diagnostic challenges due to their diverse etiology and varied clinical manifestations. This article critically reviews the anatomy of the carotid space and highlights the spectrum of pathologies within this complex region, illustrated by three case studies. The cases were examined with ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI). Schwannomas appeared heterogeneously hypodense on plain CT and partially hyperdense on contrast-enhanced CT (CECT), with displacement of adjacent vessels. Vagal-origin schwannomas caused the anteromedial displacement of the internal carotid artery. Paragangliomas were typically homogeneously hyperdense on CECT, with lateral displacement of the internal carotid artery when of carotid body origin. The management of carotid space lesions depends on the resectability of the tumors; unresectable tumors are managed with chemotherapy. This overview enhances clinical understanding and diagnostic accuracy, facilitating improved patient outcomes in managing carotid space lesions.

Fluorescence-guided minimally-invasive resection of abdominal paragangliomas using indocyanine green

This retrospective study explores the utility of near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) in enhancing the intraoperative identification and guidance for the resection of abdominal paragangliomas. They can be challenging to detect during minimally invasive surgery, due to their anatomical location, varying size and similar appearance in regard to their surrounding tissue. Patients with suspected abdominal paragangliomas planned for a minimally-invasive resection were included. As part of standard of care they received single intravenous dose of 5 mg ICG after abdominal exploration. NIR fluorescence imaging of the anatomical region of the suspected lesion was performed immediately following intravenous administration, to assess fluorescence signals, intraoperative identification, and histopathological correlation. Out of five resected suspicious lesions, four were imaged with NIR fluorescence, pathology confirming four as paragangliomas, the latter turned out to be an adrenal adenoma. NIR fluorescence identified all four lesions, surpassing the limitations of white-light visualization. Homogeneous fluorescence signals appeared 30-60 s post-ICG administration, which lasted up to 30 min. The study demonstrates the feasibility and potential clinical value of fluorescence-guided minimally-invasive resections of abdominal paragangliomas using a single intravenous ICG dose. These findings support the scientific basis for routine use of ICG-fluorescence-guided surgery in challenging anatomical cases, providing valuable assistance in lesion detection and resection.

An Aberrant Case of Pheochromocytoma in a Young Adult Presenting With Secondary Hypertension: A Case Report With Review of the Literature

Pheochromocytoma (PCC) is a rare neuroendocrine catecholamine-secreting tumour of the adrenal gland. It originates from the chromaffin cells found within the adrenal medulla or the extra-adrenal paraganglia. We present a case report of a 24-year-old female who presented with hypertension, headache, palpitations, chest pain and blurry vision. On ultrasound evaluation, a right suprarenal mass was noted, which was further evaluated using contrast-enhanced computed tomography (CT). Based on our imaging findings, the patient was diagnosed with a case of right-sided pheochromocytoma. The patient was operated on, and our diagnosis was confirmed with histopathological examination.

Functional retroperitoneal paraganglioma invading the inferior vena cava in the elderly, a case report and literature review

INTRODUCTION AND IMPORTANCE

Phaeochromocytomas and paragangliomas are rare neuroendocrine neoplasms that grow outside the adrenal gland and arise from the primitive neural crest cells. The retroperitoneal location is extremely rare with an incidence of 2-8 per million.

CASE PRESENTATION

Here we report a case of an 80 years old man presenting with abdominal pain and vomiting associated with hypertensive peaks and weight loss. CT scan showed a retroperitoneal para-aortic tumor invading the inferior vena cava, with significantly elevated urinary catecholamine levels. Histopathological and immunohistochemistry examinations confirmed the diagnosis of paraganglioma. A medical preparation by alpha-blockers was performed. Complete resection of the tumor with the reconstruction of the vena cava was achieved without postoperative complications. After surgery, blood pressure and HbA1c were on the targets and the urinary catecholamine levels were normal.

CLINICAL DISCUSSION

The diagnosis of paragangliomas is suspected by clinical symptoms in the case of functional paragangliomas and the confirmation is biological by the plasmatic or urinary catecholamines. Non-functional paragangliomas often represent a diagnostic challenge. In our case, the large size, the location of the tumor, and the invasion of adjacent structures represented a surgical challenge to perform a complete resection.

CONCLUSION

In the elderly, this pathology is quite uncommon. Retroperitoneal paraganglioma is a rare location of this type of tumor. Endocrinologists, surgeons, and anesthesiologists should work together to ensure an appropriate diagnosis and treatment of paraganglioma. The gold standard treatment is the complete resection after a medical preparation.

Mediastinal Paraganglioma: A retrospective analysis of 51 cases

BACKGROUND

Paragangliomas are rarely found in the mediastinum, where they account for a small proportion of mediastinal masses. This study aimed to better characterize the presenting features and relevant aspects in optimizing the diagnosis and treatment of mediastinal paragangliomas.

METHODS

A computer-assisted search of electronic health records was performed to identify adult patients (≥18 years) who underwent evaluation for a primary mediastinal paraganglioma at Mayo Clinic between January 2000 and April 2022. Medical charts, laboratory tests and radiology images were reviewed to collect data.

RESULTS

The study included 51 patients, each with a single mediastinal paraganglioma. The median age was 47 years (IQR: 39-67), 67% females. Symptoms of catecholamine excess were manifest in 39% of patients, and 14% presented with mass effect, while the remaining 47% had no paraganglioma-related symptoms. Genetic testing was performed in 35 patients; 66% harbored a pathogenic variant in the succinate dehydrogenase enzyme complex. Most paragangliomas (71%) were in the middle mediastinum and showed uptake of intravenous contrast on chest imaging. Biopsies were performed in 30 (59%) patients; 27% were inconclusive and 10% resulted in major complications. Surgical resection occurred in 75%, primarily for relief of symptoms (50%) followed by proximity to critical structures (45%). Perioperative complications were common (66%), but there were no cases of local tumor recurrence during the follow-up period (median 8 years; IQR: 4-13).

CONCLUSION

Mediastinal paragangliomas are most located in the middle mediastinum and can often be diagnosed noninvasively using a combination of clinical, biochemical, and radiological features.

Unusual presentation of a rare catecholamine-secreting sinonasal paraganglioma

Our patient is a man in his mid-20s with an atypical presentation of a catecholamine-secreting sinonasal paraganglioma. He was referred to our tertiary otolaryngology unit for persistent right infraorbital numbness. A nasoendoscopic examination demonstrated a smooth mass arising from the posterior aspect of the right middle meatus. There was also right infraorbital paraesthesia. Imaging revealed a lesion in the right pterygopalatine fossa. Blood investigations revealed significantly elevated serum normetanephrine levels. The lesion was demonstrated to be octreotide-avid with no other lesions detected. The presumptive diagnosis of a catecholamine-secreting paraganglioma was made, and an endoscopic resection of the tumour was performed. Histopathology of the tumour demonstrated a 'zellballen' growth pattern consistent with a paraganglioma. Catecholamine-secreting sinonasal paragangliomas are exceedingly rare with multifaceted challenges. More studies are required to improve our knowledge of this condition.

Diagnostic approach for mediastinal masses with radiopathological correlation

PURPOSE

Mediastinal masses have various histopathological and radiological findings. Although lymphoma is the most common type of tumor, thymic epithelial and neurogenic tumors are common in adults and children, respectively, but several other types are difficult to distinguish. No previous review has simply and clearly shown how to differentiate mediastinal masses.

METHOD

We conducted a review of the latest mediastinal classifications and mass differentiation methods, with a focus on neoplastic lesions. Both older and recent studies were searched, and imaging and histopathological findings of mediastinal masses were reviewed. Original simple-to-use differentiation flowcharts are presented.

RESULTS

Assessing localizations and internal characteristics is very important for mediastinal mass differentiation. The mass location and affected organ/tissue should be accurately assessed first, followed by more qualitative diagnosis, and optimization of the treatment strategy. In 2014, the International Thymic Malignancy Interest Group presented a new mediastinal clinical classification. In this classification, mediastinal masses are categorized into three groups according to location: prevascular (anterior)-, visceral (middle)-, and paravertebral (posterior)-compartment masses. Then, the internal characteristics and functional images are evaluated.

CONCLUSIONS

Differentiation of mediastinal masses is very difficult. However, if typical imaging findings and clinical characteristics are combined, reasonable differentiation is possible. In each patient, proper differential diagnosis may contribute to better treatment selection.

Gallbladder Paraganglioma: A Mysterious Histological Finding

Gallbladder paragangliomas are extremely rare with only a handful of cases reported so far. There are no definitive guidelines for the management of gallbladder paragangliomas due to their rarity. We present a case of a 53-year-old male who was found to have gallbladder paraganglioma post-laparoscopic cholecystectomy, performed for right upper abdominal pain. On review of the literature, all previously reported cases had been nonsecretory and benign. For patients who have no symptoms of secretory paragangliomas and no family history of endocrine syndromes, cholecystectomy and clinical follow-up may be a sufficient initial management following an incidental finding of gallbladder paraganglioma.

Bilateral Conjugating Carotid Body Tumor and Associated Jugular Vein Aneurysm

Carotid body tumors (CBTs) originate from the paraganglionic tissue in the bifurcation of the common carotid artery. Magnetic resonance (MR) imaging is a commonly used diagnostic method in the preoperative diagnosis of these tumors. In this study, we demonstrated an isthmus between the right and left carotid body tumors in a patient with bilateral CBT. The left CBT also was associated with a saccular aneurysm of left external jugular vein.

Follicular Neoplasm of Thyroid Revisited: Current Differential Diagnosis and the Impact of Molecular Testing

The diagnosis of "follicular neoplasm" (FN) in thyroid cytopathology has a long history that originated not long after the practice of fine-needle aspiration (FNA) of thyroid nodules. From the outset, this interpretive category was intended to convey a set of differential diagnoses rather than a precise diagnosis, as key diagnostic features, such as capsular and vascular invasion, were not detectable on cytology preparations. Cytologic-histologic correlation studies over the past several decades have shown that FN interpretation can be applied to the spectrum of nonneoplastic tumors to carcinomas. Most tumors classified as FN include follicular adenoma, follicular carcinoma, noninvasive follicular thyroid tumor with papillary-like nuclear features, and follicular variant of papillary thyroid carcinoma. Less common entities that may be classified as FN on FNA include hyalinizing trabecular tumor (HTT), poorly differentiated thyroid carcinoma, medullary carcinoma, and nonthyroidal lesions such as parathyroid tissue, paraganglioma, and metastatic tumors. Advances in our ability to detect characteristic molecular alterations (eg, GLIS gene rearrangements for hyalinizing trabecular tumor) in FNA samples may assist in the identification of some of these entities. In this review, we summarize the pathophysiology, history, and evolution of the terminology and the current differential diagnosis according to the recently published 2022 World Health Organization classification, molecular testing, and management of nodules classified as FN.

Pancreatic paraganglioma with multiple lymph node metastases found by spectral computed tomography: A case report and review of the literature

BACKGROUND

Primary pancreatic paraganglioma is exceedingly rare. Most patients with pancreatic paraganglioma lack a typical clinical presentation, and the tumor is difficult to accurately differentiate from other pancreatic neuroendocrine tumors, making the misdiagnosis rate extremely high. Surgical excision is the primary treatment modality but is considered high risk. Because of its rich vascularity, the tumor easily bleeds during surgery, especially malignant paragangliomas invading large blood vessels. Thus, a thorough preoperative evaluation of the tumor is necessary. Here, we report a primary malignant pancreatic paraganglioma, the second such case in a young patient that was successfully resected surgically.

CASE SUMMARY

A 26-year-old female patient was admitted to the hospital with unexplained abdominal pain. Dual-layer spectral-detector computed tomography (DLCT) revealed a mixed density mass in the pancreatic body and tail. The patient was transferred to our hospital after previous failed surgical resection at other hospitals. The patient and her family strongly desired surgery. After a thorough preoperative evaluation and adequate preparation, a large mass with the greatest dimension of 8.0 cm was successfully resected. The final pathological diagnosis was malignant paraganglioma. The patient was discharged in good condition 2 wk postoperatively.

CONCLUSION

The rare malignant pancreatic paraganglioma reported here was difficult to diagnose preoperatively. Early filling of the draining vein may be a crucial diagnostic imaging feature. DLCT can provide more precise information for surgical resection through dual-energy imaging.

Jugular Paraganglioma Presenting with a Tumor Thrombus Extending from Posterior Fossa to Right Atrium and Multiple Skeletal Metastases

INTRODUCTION

Paragangliomas are tumors of neuroendocrine origin, may appear in different localizations, and are related to the autonomic nervous system. Paragangliomas are generally asymptomatic and may rarely appear with adrenergic symptoms, and clinical findings depend on the catecholamines they secrete. Extra-adrenal paragangliomas are mostly benign, like all paragangliomas. Malignancy criteria consist of local recurrence, metastasis after total resection, and presence of distant metastasis during primary diagnosis.

CASE PRESENTATION

This report presents the case of a 31-year-old man with jugular paraganglioma, multiple skeletal metastases, and a long-segment tumor thrombus. Imaging procedures showed a continuous tumor thrombus extending from the posterior fossa to the right atrium and metastases in C2, T1, T6, T8, L5, and right humerus. Histopathological assessment of the metastasis in C2 identified malignant paraganglioma. Curative surgery was not an option for this patient, hence combined chemotherapy was given.

CONCLUSION

In cases of malignant paraganglioma with multiple distant metastases, chemotherapy and radiotherapy are feasible treatment methods.

Bladder paraganglioma after kidney transplantation: A case report

BACKGROUND

Kidney transplantation is associated with an increased risk of tumors in the urinary bladder. Among all the pathological types of tumors in the bladder, paraganglioma, which arises from extra-adrenal paraganglia and consists of chromaffin cells, is rare. Paragangliomas might cause severe clinical symptoms due to catecholamine hypersecretion or mass compression. Bladder paragangliomas are rare, especially those appearing after kidney transplantation. Here, we report a case of bladder paraganglioma developing after kidney transplantation.

CASE SUMMARY

A 63-year-old woman received a kidney transplant 12 years ago and took oral immunosuppressants (cyclosporine, mizoribine, and methylprednisolone) for regular post-transplant treatment. The patient felt no discomfort and she came to the hospital for a routine checkup. A mass located in the bladder was incidentally discovered by computed tomography, and she underwent surgical treatment. A 2 cm × 2 cm invasive mass was found in the trigone of the bladder and the mass was removed. The diagnosis of paraganglioma was confirmed by morphology and immunophenotyping. The patient had a good prognosis and is still alive.

CONCLUSION

Paraganglioma can grow in the bladder, which might cause no clinical symptoms. The diagnosis mainly depends on morphology and immunophenotyping. Surgical resection is an important treatment option for such patients.

Carotid Body Tumor: Our Experience with 42 Patients and a Literature Review

To review characteristics, signs, diagnostic methods, and surgical complications in patients with carotid body tumor, in addition to a literature review. This was a cross-sectional study carried out on 42 patients with carotid body tumors referred to Al-Zahra hospital of Isfahan from January 1, 2016, to December 31, 2019. The studied characteristics included age at the onset of symptoms, gender, symptoms, duration of symptomatic status before diagnosis, diagnostic methods, pathological outcome, tumor stage, and surgical complications. The collected data were analyzed using SPSS 21. In this study, 34 patients (80.96%) were female. The mean age at the onset of symptoms was 54.41 years. The mean duration of symptoms before diagnosis was 12.55 months. There was no significant difference between genders for the age and duration of symptoms before diagnosis (p > 0.05). Symptoms were mainly painless mass, hoarseness, coughing, earache, tinnitus, and headache. After surgery, two cases of permanent cranial nerve injuries were found. Thirty-nine patients (93%) were diagnosed by ultrasound imaging and CT scan. We had one case of arterial repair. There was one malignant and one functional tumor. According to the results, carotid body tumor is more common in females especially on the right side. Bilateral tumors are prevalent in females. This mass should be removed by surgery at the time of diagnosis in cases where the patient is not at high risk for surgery due to comorbidities, and the risk of complications following surgery is low.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-021-02453-8.

Spontaneous Retroperitoneal Bleeding as a Complication of Unusual Renal Paraganglioma

Spontaneous retroperitoneal bleeding is a rare occurrence that might have catastrophic implications. We present a 58-year-old male with a 4-day history of progressively worsening left-sided flank pain due to retroperitoneal hemorrhage from a nonfunctional renal paraganglioma. Abdominal contrast CT scan was helpful in locating the tumor, estimating tumor size and extent of bleeding, visualizing the interaction between the tumor and the surroundings, and ruling out any potential metastasis; however, it lacked specificity in identifying the origin of the mass, needing histologic investigation for a conclusive diagnosis. MRI was not available at our center. We report a rare case of spontaneous retroperitoneal bleeding as a complication of an unusual nonfunctional renal paraganglioma, which was initially misdiagnosed as renal cell carcinoma but later confirmed by postoperative histopathology.

An incidental finding of retroperitoneal paraganglioma during the coronavirus disease 2019 pandemic: a case report

Background

Extra-adrenal paraganglioma of the retroperitoneum is a very rare neoplasm arising from cells of the primitive neural crest. Although paragangliomas are considered benign and are often found incidentally, they have the potential to metastasize.

Case presentation

We report the case of a 68-year-old Caucasian woman with an incidental diagnosis of retroperitoneal paraganglioma that was discovered on chest computed tomography performed for high suspicion of coronavirus disease 2019 pneumonia. The patient showed no metastasis and was successfully treated by complete surgical removal of the tumor.

Conclusion

As the diagnosis of paragangliomas is often delayed because of absent clinical symptoms, they represent a significant diagnostic challenge. Although surgery may exacerbate coronavirus disease 2019 infection, surgical resection of this tumor is prioritized, given its malignancy potential, and it must be performed as soon as no infection is detected.

Neuroendocrine Neoplasms of the Female Genitourinary Tract: A Comprehensive Overview

Simple Summary

Primary neuroendocrine neoplasms (NENs) are a rare, heterogeneous group of tumors that include well-differentiated neuroendocrine tumors, poorly differentiated neuroendocrine carcinoma, and paraganglioma. NENs in the urinary tract are observed in <0.05% of individuals, in whom the bladder is the most common site. In this review, we described the epidemiology, pathogenesis, imaging, staging, and management of the genitourinary NENs.

Abstract

Primary neuroendocrine neoplasms are a rare heterogeneous group of tumors that include well-differentiated neuroendocrine tumors, poorly differentiated neuroendocrine carcinoma, and paraganglioma. An extensive literature search was used to compile the data regarding epidemiology, pathogenesis, imaging features, and management of the urinary system NENs. We also included the updated staging of the NENs at various locations of the urinary system.

It's Not All in Your Head: Thoracic Manifestations of Neurologic Diseases and Disorders

Myriad conditions may affect both the neurologic system and the thorax, while other diseases primarily affecting the thorax may manifest with neurologic abnormalities. Correlation of signs, symptoms, and imaging findings in the neurological system with those in the thorax can help diagnose certain conditions and/or guide further diagnostic work-up and treatment. We will review and illustrate the imaging appearance of several systemic/neurological diseases with thoracic manifestations as well as discuss conditions in the thorax that can lead to neurologic symptoms.

Paragangliomas of the head and neck

Paragangliomas are rare neuroendocrine tumors that can be found from the skull base to the pelvis. Head and neck paragangliomas have been historically treated with surgery. However, surgical resection adds risk of injury to vascular structures and cranial nerves that can lead to morbidity such as hoarseness, dysarthria, dysphagia, or aspiration. Recently, improved understanding of the behavior of these tumors and increasing experience in non-surgical treatments such as observation and radiation therapy, have changed the paradigms of management of this entity. Multiple series now show a trend towards a more conservative management, with a higher percentage of patients being observed or treated with radiotherapy. Several factors should be taken into consideration when deciding the most appropriate treatment for head and neck paragangliomas, starting by differentiating carotid body tumors from non- carotid body tumors. In general, surgical resection is normally recommended for carotid body tumors as the complications from treatment are usually minimal. In contrast, for non- carotid body tumors, surgery is often associated with significant functional impairment due to cranial nerve paralysis. As such, non-surgical treatment is now usually recommended for this subset of head and neck paragangliomas. In young patients with no comorbidities and a small to medium carotid body tumors, surgery should be considered. Moreover, surgery should be offered for secreting tumors, malignant tumors, tumors with rapid growth or increase in symptomatology, and when radiotherapy cannot be performed. Conversely, conservative management with active surveillance or radiotherapy can be offered in the remaining cases in order to avoid unnecessary morbidity while still providing acceptable tumor control.

Imaging features of retroperitoneal extra-adrenal paragangliomas in 10 dogs

Retroperitoneal paragangliomas are rare tumors of the neuroendocrine system. Only a few canine case reports are available with rare descriptions of their imaging features. The objectives of this multi‐center, retrospective case series study were to describe the diagnostic imaging features of confirmed retroperitoneal paragangliomas and specify their location. Medical records and imaging studies of 10 affected dogs with cytological or histopathologic results concordant with retroperitoneal paragangliomas were evaluated. Dogs had a median age of 9 years. Four of them had clinical signs and laboratory reports compatible with excessive production of catecholamines. Six ultrasound, four CT, four radiographic, and one MRI studies were included. The paragangliomas did not have a specific location along the aorta. They were of various sizes (median 33 mm, range: 9–85 mm of length). Masses had heterogeneous parenchyma in six of 10 dogs, regardless of the imaging modality. Strong contrast enhancement was found in all CT studies. Encircling of at least one vessel was detected in six of 10 masses, clear invasion of a vessel was identified in one of 10 masses. In five of 10 cases, the masses were initially misconstrued as lymph nodes by the on‐site radiologist. Retroperitoneal paragangliomas appear along the abdominal aorta, often presenting heterogeneous parenchyma, possibly affecting the local vasculature, and displaying strong contrast enhancement on CT. Clinical signs can be secondary to mass effects or excessive catecholamine production. Underdiagnosis and misdiagnosis of this tumor are suspected as they can be silent, of small size, or confused with other structures.

Paraganglioma masquerading as a primary liver lesion: A rare entity discovered during surgery

A 54-year-old woman with controlled hypertension presented with abdominal pain and weight loss. Imaging revealed a 6.6 cm liver lesion. During resection, she became severely hypertensive and diagnosis was paraganglioma. Hepatic paragangliomas are exceedingly rare but must be considered in the differential of abdominal mass even without typical clinical symptoms.

Unclear retroperitoneal tumors, an interdisciplinary challenge - A case report and review of the literature

INTRODUCTION AND IMPORTANCE

Unclear retroperitoneal tumors impose major challenges for clinicians. Tumors can originate primarily from retroperitoneal tissue or secondarily invade into the retroperitoneum. While benign lesions also occur, malignant tumors are far more common. Clinical presentation depends on replacement or invasion of other organs and is therefore highly variable. The heterogeneous tumor composition makes a definitive preoperative diagnosis difficult. Surgical resection is the gold standard for treatment but often proves challenging due to frequent involvement of large retroperitoneal vessels.

CASE PRESENTATION

We present the case of a 70-year old woman diagnosed with a large, unclear retroperitoneal tumor. Initial clinical symptoms were increasing dyspnea and dysphagia in our clinic. Gastroenterologic and cardiologic workup was unremarkable. Computed Tomography (CT) revealed a large retroperitoneal mass in the right upper abdomen with severe displacement of the inferior vena cava and renal veins. The patient was scheduled for primary tumor resection. The procedure was challenging due to the vessel involvement and large blood pressure alterations during tumor mobilization. The post-op pathologic workup then revealed the rare finding of a completely resected paraganglioma. The post-surgical course was uneventful. One year after diagnosis, the patient is relapse-free.

CLINICAL DISCUSSION

Among retroperitoneal tumors, paragangliomas and pheochromocytomas are rare tumor entities. Asymptomatic, sporadic disease is hard to identify preoperatively and can cause unexpected complications in the OR. An experienced team is crucial in achieving best short- and long-term outcomes.

CONCLUSION

This case impressively shows the challenges of retroperitoneal tumors and the importance of interdisciplinary work in these cases.

Gallbladder paraganglioma with hemorrhage: A case report and literature review

Gallbladder paraganglioma (GP) is a rare tumor, with only 12 cases reported in the literature to date. Due to its rarity, clinical information of GP is insufficient. We present a case of GP in a 48-year-old female along with a literature review of all GP cases described to date. A 48-year-old female presented with intermittent right upper abdominal pain. Preoperative imaging revealed a hematoma in the gallbladder lumen without any definite etiology. Laparoscopic cholecystectomy was performed. Gross examination of the gallbladder revealed multiple small stones and a large hematoma as well as a 1.6-cm-sized polypoid mass at the gallbladder fundus. Microscopic study of the polypoid mass showed a zellballen appearance. Immunohistochemical analysis revealed that the mass was positive for synaptophysin, CD56, and chromogranin, suggesting GP. GP is difficult to diagnose because of non-specific clinical findings. Almost all GP cases are diagnosed based on histologic findings after cholecystectomy. Simple cholecystectomy was performed as a treatment in all reported cases of GP, including our case. There was no postoperative tumor recurrence or metastasis after surgery.

Multiple Paragangliomas in the Carotid Body, Adrenal and Extra-Adrenal Retroperitoneal Locations

Paragangliomas are chromaffin cell tumors that arise from neural crest cells and are extremely rare. Multiple paragangliomas in different locations of the neck and abdomen in the same patient are highly uncommon. We give the instance of a hypertensive male aged 42 years with a history of breathlessness, chest pain, and excessive perspiration for 10 days. Computed tomography of neck and abdomen revealed solid homogenous intensely enhancing masses in the left adrenal of size 64 x 45 x 52 mm [AP x TR x CC (anteroposterior x transverse x craniocaudal)], left paraaortic region of size 41 x 28 x 29 mm [CC x TR x AP (craniocaudal x transverse x anteroposterior)] and at the division of the left common carotid artery of size 17 x 15 x 11 mm (CC x TR x AP). The patient underwent a diagnostic laparotomy and resected tumors were diagnosed as paragangliomas. The possibility of paragangliomas should always be considered when hypervascular masses are encountered in certain locations of the body. Presence of such a lesion must prompt further imaging of the common sites of paragangliomas for the detection of occult synchronous paragangliomas. Routine screening at timely intervals in patients previously diagnosed with paraganglioma may aid in the earlier detection of metachronous tumors.

Pancreatic/peripancreatic neurogenic tumor; little known masses not to be missed

BACKGROUND

Retroperitoneal neurogenic tumors are extremely rare pathological entities; therefore, few clinical features and natural courses, especially originating from the pancreatic/peripancreatic regions, have been reported. This study aimed to investigate the clinicopathological features of pancreatic and peripancreatic neurogenic tumors and assess the diagnostic value of computed tomography (CT) and endoscopic ultrasound-guided fine needle biopsy (EUS-FNB).

METHODS

Between 2006 and 2018, patients who were diagnosed with neurogenic tumors were included. In total, 90 histologically confirmed cases of neurogenic tumors located in the pancreatic/peripancreatic regions were selected for analysis.

RESULTS

The mean age was 49.2 ± 13.1 years. There were no differences in sex distribution of the tumors. Schwannomas (44.4%) and paragangliomas (41.1%) were the most common neurogenic tumors. The sensitivity of CT was 62.2% in 90 cases. EUS-FNB was performed in 30 cases and the sensitivity of it was 83.3%. The diagnosis of neurogenic tumors with EUS-FNB or CT was not significantly associated with tumor location and size. Surgical resection was performed in 78 cases. Of the 12 patients who did not undergo surgery, 10 cases were followed-up without any increase in tumor size.

CONCLUSIONS

Through the present study, we verified radiological, pathological, and clinical aspects of the pancreatic/peripancreatic neurogenic tumors which little known before, therefore, this study can serve as the basis for research to present an optimal diagnosis and treatment of neurogenic tumors. In addition, EUS-FNB is useful in the diagnosis of pancreatic/peripancreatic neurogenic tumors with relatively high sensitivity and can help establish therapeutic plans before the surgery.

Primary pancreatic paraganglioma harboring lymph node metastasis: A case report

BACKGROUND

Primary pancreatic paragangliomas are extremely rare tumors. Limited by the diagnostic efficacy of histopathological examination, their malignant behavior is thought to be associated with local invasion or metastasis, with only four malignant cases reported in the literature to date. As pancreatic paragangliomas share similar imaging features with other types of pancreatic neuroendocrine neoplasms, they are difficult to diagnose accurately without the support of pathological evidence. As primary pancreatic paragangliomas are rare, especially those accompanied by lymph node metastasis, there is currently no consensus on treatment. Herein, we report a case of primary pancreatic paraganglioma with lymph node metastasis.

CASE SUMMARY

A mass located in the pancreatic body was incidentally discovered on computed tomography in a 41-year-old Tibetan man. Distal pancreatectomy was subsequently performed and a 4.1 cm × 4.2 cm tumor was found embedded in the body of the pancreas during surgery. Histological examination confirmed the characteristics of paraganglioma in which the neoplastic chief cells were arranged in a classic Zellballen pattern under hematoxylin-eosin staining. Further, immunohistochemistry demonstrated that the sustentacular cells in the tumor tissue were positive for S-100 protein, and neoplastic cells and pancreatic draining lymph nodes were positive for chromogranin A and synaptophysin; thus, the presence of lymph node metastasis (two of the eight resected pancreatic draining lymph nodes) was also confirmed. A diagnosis of primary pancreatic paraganglioma with lymph node metastasis was finally established. The patient remained disease-free for 1 year after the surgery.

CONCLUSION

A definite diagnosis of pancreatic paraganglioma mainly depends on postoperative histopathological and immunohistochemical examinations. Surgical resection may be the first treatment of choice for patients with primary pancreatic paraganglioma that has metastasized to the lymph nodes.

Differentiation of Jugular Foramen Paragangliomas versus Schwannomas Using Golden-Angle Radial Sparse Parallel Dynamic Contrast-Enhanced MRI

BACKGROUND AND PURPOSE

Accurate differentiation of paragangliomas and schwannomas in the jugular foramen has important clinical implications because treatment strategies may vary but differentiation is not always straightforward with conventional imaging. Our aim was to evaluate the accuracy of both qualitative and quantitative metrics derived from dynamic contrast-enhanced MR imaging using golden-angle radial sparse parallel MR imaging to differentiate paragangliomas and schwannomas in the jugular foramen.

MATERIALS AND METHODS

A retrospective study of imaging data was performed on patients (n = 30) undergoing MR imaging for jugular foramen masses with the golden-angle radial sparse parallel MR imaging technique. Imaging data were postprocessed to obtain time-intensity curves and quantitative parameters. Data were normalized to the dural venous sinus for relevant parameters and analyzed for statistical significance using a Student t test. A univariate logistic model was created with a binary output, paraganglioma or schwannoma, using a wash-in rate as a variable. Additionally, lesions were clustered on the basis of the wash-in rate and washout rate using a 3-nearest neighbors method.

RESULTS

There were 22 paragangliomas and 8 schwannomas. All paragangliomas demonstrated a type 3 time-intensity curve, and all schwannomas demonstrated a type 1 time-intensity curve. There was a statistically significant difference between paragangliomas and schwannomas when comparing their values for area under the curve, peak enhancement, wash-in rate, and washout rate. A univariate logistic model with a binary output (paraganglioma or schwannoma) using wash-in rate as a variable was able to correctly predict all observed lesions (P < .001). All 30 lesions were classified correctly by using a 3-nearest neighbors method.

CONCLUSIONS

Paragangliomas at the jugular foramen can be reliably differentiated from schwannomas using golden-angle radial sparse parallel MR imaging-dynamic contrast-enhanced imaging when imaging characteristics cannot suffice.

Neuroimaging of Dizziness and Vertigo

Dizziness and vertigo are common symptoms in the primary care and emergency settings, resulting in a significant decrease in quality of life and a high cost burden to the US health care system. The etiology of these symptoms is difficult to elucidate owing to a wide range of diseases with overlapping manifestations. The broad differential diagnosis based on whether the disease process is central or peripheral is showcased. Each differential will be categorized into neoplastic, infectious or inflammatory, structural, traumatic, and iatrogenic causes. Computed tomography scans, MRI, and vascular imaging are frequently complimentary in providing diagnoses and guidance in management.

Primary extra-pancreatic pancreatic-type acinar cell carcinoma in the right perinephric space: A case report and review of literature

BACKGROUND

Primary extra-pancreatic pancreatic-type acinar cell carcinoma (ACC) is a rare malignancy, and has only been reported in the gastrointestinal tract, liver, and lymph nodes until now. Extra-pancreatic pancreatic-type ACC in the perinephric space has not been reported. Herein, we report the first case of ACC in the perinephric space and describe its clinical and imaging features, which should be considered when differentiating perinephric space neoplasms.

CASE SUMMARY

A 48-year-old man with a 5-year history of hypertension was incidentally found to have an asymptomatic right retroperitoneal mass during a routine health check-up. Laboratory tests were normal. Abdominal computed tomography and magnetic resonance imaging showed an oval hypervascular mass with a central scar and enhanced capsule in the right perinephric space. After surgical resection of the neoplasm, the diagnosis was primary extra-pancreatic pancreatic-type ACC. The patient was alive without recurrence or metastasis during a 15-mo follow-up.

CONCLUSION

This is the first report of an extra-pancreatic ACC in right perinephric space, which should be considered as a possible diagnosis in perinephric tumors.

Tracheal Paraganglioma: A Case report and Review of the Pertinent Literature

The trachea is a sporadic origin of paraganglioma. The purpose of the present study was to identify the features of tracheal paraganglioma and reveal the effectiveness of computed tomography (CT) and magnetic resonance imaging (MRI) by reviewing both previous and current cases. In cases of tracheal tumors, we need to consider the bleeding risk associated with a biopsy, as the tumor may be paraganglioma, which is hypervascular. If a biopsy is not available, then CT and MRI can aid in making a pre-operative diagnosis. MRI in particular is useful for long-term observations.

Radiologic-Pathologic Correlation of Primary Retroperitoneal Neoplasms

An earlier incorrect version of this article appeared in print. The online version is correct.

Potential application value of PET/computed tomography in retroperitoneal leiomyosarcoma and a literature review

OBJECTIVE

To analyze the fluorine-18 fludeoxyglucose PET/computed tomography (18F-FDG PET/CT) findings of retroperitoneal leiomyosarcoma (RLMS) and the role of this method in differentiating between benign and malignant masses and classifying the malignant degree to improve the understanding of this rare disease.

METHODS

Eight leiomyomas (A group), 13 RLMSs (B group), and 20 postoperative recurrence/metastasis RLMSs (C group) were enrolled. PET/CT features of B group were analyzed. The differences of metabolic parameters between three groups were compared, receiver operating characteristic (ROC) curve analysis was performed to group A and B, and correlation analysis was performed to subgroup B.

RESULTS

(1) The RLMS patients were more likely to be female, and PET/CT showed a high degree of heterogeneous metabolism in the soft tissue mass. (2) The standardized uptake value (SUV) of RLMS were significantly higher than those of benign leiomyomas (P < 0.05). The area under the ROC curve was 0.909, the sensitivity and specificity for diagnosing RLMS were 0.923 and 0.750, respectively, The SUVmax and SUVstd of primary RLMS were moderately associated with the Ki67 index. The mean SUVmax in the G1, G2 and G3 subgroups increased successively (4.15 ± 0.35, 6.47 ± 0.83, and 10.13 ± 4.29, respectively). (3) Primary RLMS was characterized by local invasion, but hematogenous metastasis and lymph node metastasis were rare. Postoperative recurrence/metastasis of RLMS was characterized by local recurrence and hematogenous metastasis, but lymph node metastasis was rare.

CONCLUSION

PET/CT has potential value in the preoperative staging, benign and malignant differentiation, malignant degree classification and postoperative follow-up of RLMS.

Mediastinal Mass: An Unusual Location for a Paraganglioma

A 50-year-old man presented to the hospital for workup of a symptomatic inguinal hernia. At presurgical workup, findings from a contrast material-enhanced CT of the chest, abdomen, and pelvis revealed a large, well-defined and enhancing middle mediastinal mass arising from the right ventricular outflow tract. The mass was ultimately deemed resectable due to preserved fat planes between the mass and other mediastinal structures and the preservation of the right and left coronary arteries. The tumor was diagnosed as a mediastinal paraganglioma at histologic assessment. Keywords: Adults, Angiography, CT-Angiography, MR-Angiography, Cardiac, Neoplasms-Primary ©RSNA, 2021.

Imaging of nonatheromatous carotid artery disease

Imaging diagnosis of nonatheromatous carotid artery disease is challenging due to its low prevalence in contrast to that of atheromatous disease. Congenital anomalies are frequently discovered incidentally, as the chronicity of these conditions allows for compensatory flow development. The inflammatory conditions typically present with nonspecific courses, and a high clinical suspicion along with timely imaging evaluation can guide the diagnosis. Carotid dissection is the result of a partial disruption of the arterial wall and can be seen in previously healthy patients, in patients with underlying noninflammatory arteriopathies or trauma. Traumatic injuries to the carotid artery may occur under many different conditions and mechanisms and timely recognition of high-risk patients improves patient outcomes. Although free-floating thrombi (FFT) formation is typically seen with atherosclerotic plaque rupture, different conditions may also predispose to FFT. In this review article, we study the different imaging features of nonatheromatous carotid artery disease using ultrasonography, computed tomography angiography, magnetic resonance angiography, and digital subtraction angiogram.

Paraganglioma with highly malignant potential involving the rib - Case report and review of the literature

Paragangliomas are rare neuroendocrine tumors arising from paraganglion cells in sympathetic or parasympathetic chains, which may develop in the abdomen, chest, skull base, and neck. As paragangliomas have a wide range of imaging features, the diagnosis often requires tissue sampling. We present a unique case of a paraganglioma which originally presented as a rib tumor.

A 64-year-old male with right flank pain for 2 months’ was referred for a noncontrast renal colic CT. He was found to have a 3.7 × 3.5 cm soft tissue mass invading the left posterior 9th rib and paraspinal muscle. This was fluorodeoxyglucose F 18, (¹⁸F-FDG) avid, with no other distant metabolic activity. He underwent ultrasound-guided core biopsy which revealed a diagnosis of paraganglioma. A right thoracotomy with chest wall resection of 8, 9, and 10 ribs were subsequently performed. The tumor was removed along with a small portion of adherent lung. The tumor was positive for CD56, synaptophysin and chromogranin. S-100 highlighted occasional sustentacular cells, consistent with a pathologic diagnosis of a paraganglioma. The patient remains symptom free for 6 months’ after the operation.

Our case highlights that, when paragangliomas occur within the chest wall, they may present as a rib tumor and can mimic metastasis, myeloma or other primary neoplastic etiologies originating from ribs. Both imaging and pathologic diagnosis can be challenging.

Detecting causes of pulsatile tinnitus on CT arteriography-venography: A pictorial review

Pulsatile tinnitus (PT) can be a mild or debilitating symptom. Following clinical examination and otoscopy, when the underlying aetiology is not apparent, radiological imaging can be used to evaluate further. CT arteriography-venography (CT A-V) of the head and neck has recently been introduced as a single 'one catch' modality for identifying the many causes of PT including those which are treatable and potentially serious whilst also providing reassurance through negative studies or studies with benign findings. CT A-V is performed as a single phase study allowing both arterial and venous assessment, hence limiting radiation exposure. Additional multiplanar reformats and bone reconstructions are desirable. Understanding the limitations of CT A-V is also required, with an awareness of the scenarios where other imaging modalities should be considered. The causes of PT can be divided into systemic and non-systemic categories. Non-systemic aetiologies in the head and neck should be carefully reviewed on CT A-V and include a variety of vascular causes (arteriovenous malformations/fistulas, venous or arterial aetiologies) and non-vascular causes (tumours and bony dysplasias). Venous causes (dominant, aberrant, stenosed or thrombosed venous vessels) are more common than arterial aetiologies (aberrant or stenosed internal carotid artery, aneurysms or a persistent stapedial artery). Glomus tumours that are not visible on otoscopy and osseous pathologies such as bony dehiscence and otospongiosis should also be excluded. Careful assessment of all the potential vascular and non-vascular causes should be reviewed in a systematic approach, with correlation made with the clinical history. A structured reporting template for the reporting radiologist is provided in this review to ensure all the potential causes of PT are considered on a CT A-V study. This will help in providing a comprehensive radiological evaluation, hence justifying the radiation dose and for patient assessment and prognostication.

Functional paraganglioma with tumor thrombus in the inferior vena cava, first case report

Pheochromocytoma (PHEO) is a rare neuroendocrine that tumor originated from the adrenal medulla that secrets catecholamines. Tumors from extra-adrenal chromaffin tissues are called extra-adrenal PHEO or paraganglioma (PGL). To our knowledge, adrenal PHEO and subclinical PGL with inferior vena cava (IVC) invasion had been sporadically reported, while functional PGL with IVC tumor thrombus has not been publicly reported yet. Perioperative management of those diseases is less well established because of their multidisciplinary nature and rarity. We herein present a case of primary malignant PGL with IVC invasion. A 16-year-old female patient with a history of severe paroxysmal hypertension was admitted to Peking Union Medical College Hospital on suspicion of retroperitoneal mass. In-house diagnostic work-up revealed a malignant PGL with IVC invasion, inferior mesenteric artery encasement and, aorta engagement. Multi-disciplinary discussions were held and careful preoperative preparation plans were made. After everything was ready, the functional PGL and tumor thrombus were completely resected, then a reconstruction of IVC was performed. The patient was discharged on postoperative day 14 and all her clinical symptoms disappeared afterward. No evidence of tumor residual or metastasis was found in the subsequent six months of follow-up. Gene tests were made for her and her family. Albeit its rarity, functional PGL with IVC invasion is not unresectable, a multi-disciplinary task force should be established to settle down every detail. We recommended 3-dimensional imaging reconstruction for gaining a better anatomic understanding. Literature reviews showed that complete resection is the premise of a good prognosis. In particular cases, complementary or alternative therapy like chemotherapy and ¹³¹I-metaiodobenzylguanidine might help, family hereditary genetic tests are advised as well.

Paraganglioma of Urinary Bladder in a Pediatric Patient

Paragangliomas arise from neural cells and are found in different anatomical locations in the body. Paragangliomas in the adrenal glands are called pheochromocytoma, while the others are known as extra-adrenal paragangliomas. They are usually benign and are extremely rare in children. We present a case of a 13-year-old female patient who presented with complaints of hematuria for one year and left lower lumbar pain. Imaging investigations depicted a urinary bladder mass that was causing a mass effect at the left ureteric opening and backpressure changes in the left kidney. The patient underwent transurethral resection of bladder mass, and the histopathology confirmed the presence of paraganglioma. Though the paragangliomas of the urinary bladder are extremely rare in the pediatric age group, we suggest keeping paragangliomas on differentials when investigating a patient with bladder mass.

Case Report: Totally Laparoscopic Resection of Retroperitoneal Paraganglioma Masquerading as a Duodenal Gastrointestinal Stromal Tumor

Introduction: Retroperitoneal paraganglioma (RPGL) is a rare clinical tumor derived from the retroperitoneal sympathetic paraganglion tissue. Since RPGLs are locate deeply and have no specific symptoms and imaging manifestations at the early stage, which easily causes missed diagnosis or misdiagnosis. In addition, reports on totally laparoscopic resection of RPGLs are scarce due to their close proximity to large vessels, giant size, uncertain location, and unknown malignant status.

Case Presentation: We present here the case of totally laparoscopic resection of a 6.4 × 5.4 cm RPGL that was discovered during a workup for discomfort and upper abdominal pain in a 68-year-old female patient, mimicking a gastrointestinal stromal tumor (GIST) of the duodenum, Which was confirmed as a RPGL based on the histopathological and immunohistochemical findings.

Conclusions: RPGL is a rare tumor, and the transperitoneal laparoscopic approach for the RPGL is a safe, applicable method with less trauma and quick recovery, which is worth clinical popularizing and application. Moreover, the survival prognosis of RPGL patients are related to metastasis, and lifelong follow-up should be emphasized.

Pheochromocytoma of the organ of Zuckerkandl

Paragangliomas are uncommon neuroendocrine neoplasms that occur in characteristic locations. While parasympathetic paragangliomas are mainly located at the head and neck, sympathetic paragangliomas are mostly located below the neck. Among parasympathetic paragangliomas, pheochromocytomas are the most common. Ninety percent of cases of pheochromocytomas arise within the adrenal gland. We report a case of a 63-year-old woman with an extra-adrenal pheochromocytoma of the organ of Zuckerkandl detected by CT and MRI and subsequently confirmed by postoperative histology and immunohistochemistry.

Carney Triad, Carney-Stratakis Syndrome, 3PAS and Other Tumors Due to SDH Deficiency

Succinate dehydrogenase (SDH) is a key respiratory enzyme that links Krebs cycle and electron transport chain and is comprised of four subunits SDHA, SDHB, SDHC and SDHD. All SDH-deficient tumors are caused by or secondary to loss of SDH activity. As many as half of the familial cases of paragangliomas (PGLs) and pheochromocytomas (PHEOs) are due to mutations of the SDHx subunits. Gastrointestinal stromal tumors (GISTs) associated with SDH deficiency are negative for KIT/PDGFRA mutations and present with distinctive clinical features such as early onset (usually childhood or adolescence) and almost exclusively gastric location. SDH-deficient GISTs may be part of distinct clinical syndromes, Carney-Stratakis syndrome (CSS) or dyad and Carney triad (CT). CSS is also known as the dyad of GIST and PGL; it affects both genders equally and is inherited in an autosomal dominant manner with incomplete penetrance. CT is a very rare disease; PGL, GIST and pulmonary chondromas constitute CT which shows female predilection and may be a mosaic disorder. Even though there is some overlap between CT and CSS, as both are due to SDH deficiency, CSS is caused by inactivating germline mutations in genes encoding for the SDH subunits, while CT is mostly caused by a specific pattern of methylation of the SDHC gene and may be due to germline mosaicism of the responsible genetic defect.

Imaging findings of lesions in the middle and posterior mediastinum

Lesions in the middle and posterior mediastinum are relatively rare, but there are some useful radiological clues that can be used to diagnose them precisely. It is useful to determine the affected mediastinal compartment and the locations of the main thoracic nerves on medical images for diagnosing such mediastinal lesions. Neurogenic tumors can occur in the middle mediastinum, although they generally arise as posterior mediastinal tumors. Based on the above considerations, we review various characteristic imaging findings of middle and posterior mediastinal lesions, and their differential diagnoses.

Imaging in Pulsatile Tinnitus: Case Based Review

Tinnitus refers to auditory perception of internal origin. It is a relatively common problem and affects men and women equally. Clinically, it may be divided as pulsatile or non-pulsatile and subjective and objective. Although pulsatile tinnitus (PT) is less common, it is more likely to be associated with underlying vascular tumors, lesions or anomalies. Imaging forms the baseline for evaluation of objective tinnitus, primarily in the form of computed tomography or magnetic resonance imaging. We present a review of common causes of PT, along with emphasis on key imaging findings.

Para-aortic haemangioma mimics paraganglioma on MRI

Here, we report a case of a 70-year-old man referred for an incidentally discovered left renal lesion with peri-aortic lymphadenopathy following a CT scan for back pain. A follow-up MRI scan demonstrated a Bosniak IIF left renal cyst and a T2-hyperintense para-aortic lesion concerning for extra-adrenal paraganglioma (EAP). [¹³¹I] Metaiodobenzylguanidine scintigraphy of the para-aortic lesion and urine catecholamines were equivocal. The mass was resected via a robotic approach. Histological examination revealed a haemangioma. Haemangiomas are benign vascular tumours frequently identified on imaging of the liver. Intra-abdominal haemangiomas outside of the liver, however, are rare and may have imaging characteristics that mimic EAP.

Texture analysis of T2-weighted MRI predicts SDH mutation in paraganglioma

PURPOSE

Texture analysis can quantify sophisticated imaging characteristics. We hypothesized that 2D textures computed with T2-weighted and post-contrast T1-weighted MRI can predict succinate dehydrogenase (SDH) mutation status in head and neck paragangliomas.

METHODS

Our retrospective study included 21 patients (1 to 4 tumors/patient) with 24 pathologically proven paragangliomas in the head and neck. Fourteen lesions (58%) were SDH mutation-positive. All patients underwent T2-weighted and post-contrast T1-weighted MRI sequences. Three 2D texture features of dependence non-uniformity normalized (DNN), small dependence high gray level emphasis (SDHGLE), and small dependence low gray level emphasis (SDLGLE) were calculated. Computed textures between SDH mutants and non-mutants were compared using Mann-Whitney U test. Area under the receiver operating characteristic (AUROC) curve was used to quantify the predictive power of each texture.

RESULTS

Only T2-based SDLGLE was statistically significant (p = 0.048), and AUROC was 0.71. Diagnostic accuracy was 70.8%.

CONCLUSION

2D texture parameter of T2-based SDLGLE predicts SDH mutation in head and neck paragangliomas. This noninvasive technique can potentially facilitate further genetic workup.