Every extra‘pear’ counts A 3year Retrospective Study on Imaging in Extra-Adrenal Paragangliomas with A Select Display of Exquisite Cases Abstract Id no 1207

Aim To review the location, distribution and imaging features of extra-adrenal paragangliomas presenting to a quarternary care hospital in southern India for the past 3 years and illustrate the imaging features of selective unusual presentations.

Methodology and Materials A 3 years retrospective study from December 2011 to November 2014 Data collection methods: Institutional PACS server was searched for the key words ‘paraganglioma,’ ‘glomus’ and ‘carotid body’ Data collection sources: Institutional PACS Surgical records Medical records Institutional laboratory results

Results Total no. of lesions = 67 Male : Female = 1.48 : 1 Average age at diagnosis = 44.6years [Range from 14 to 76 years] Total lesions biopsied = 38 (57%) Biopsy proven paragangliomas = 35 [Malignant paraganglioma = 1]

Radiological operations

Distribution of lesions in the body

Size distribution of lesions (cm) Average size of lesions = 4.4cm Range = 0.3cm to 9.7cm

Treatment

Features of common conditions

Carotid body lesions vs head & neck lesions

Para-falcine paraganglioma MRI of a 41year old man suspected to have a glioma shows a heterogeneously hyperintense lesion to the right of the posterior part of the falx with significant peri-lesional oedema. T1 plain and post contrast images show moderate enhancement of the solid components. MRI diagnosis was meningioma. Patient underwent excision and biopsy was reported as paraganglioma. On follow up, he had his latest MRI after 9years in December 2013 that shows no disease.

Carotid body chemodectoma 11year old with right neck swelling and pain. Colour Doppler neck showed a well-defined heterogeneous lesion at right CCA bifurcation with intralesional arterial flow. Diagnosis of carotid body tumour was suggested and no other imaging was done. Patient underwent excision, biopsy reported as paraganglioma.

Tracheal paraganglioma 22years old man presented with haemoptysis, dyspnoea and voice change. He presented 2 years later with breathing difficulty and was haemoptysis and was found to have post-op recurrence. He underwent excision with crico- tracheal resection anastomosis. Neck radiograph, lateral view shows a soft-tissue density within the tracheal lumen compromising the airway. CECT axial sections showed a well-defined, intensely enhancing, polypoidal lesion with infiltration of the posterior tracheal wall. Excision and biopsy showed paraganglioma.

Atrio-ventricular groove paraganglioma 36years old man who was incidentally detected to have a mediastinal mass. CECT axial sections show a brightly enhancing mass in the left AV groove. Peripheral curvilinear calcifiations are seen in the lateral and posterior aspect. Eccentric non-enhancing areas suggest necrosis. Patient underwent CT guided FNAC suggestive of paraganglioma.

Para-vertebral Paraganglioma 51 year old diabetic and hypertensive with back pain. CECT arterial phase axial section show an intensely enhancing lobulated soft tissue density lesion in the left para-aotic region Patient underwent CT guided biopsy and pre-operative embolisation with gelfoam Plain CT prone axial section with needle Post operative Ga-68 DOTATATE PET CT showed a DOTATATE avid residual functioning tumour and is planned for Lutetium-177 DOTATATE therapy. Patient undewent partial excision as it was adherent to the aortic wall. Surgical pathology specimen showed paraganglioma.

Metastatic Paraganglioma of the Urinary Bladder 32years old man presented with fatigue sweating and palpitations. Biopsy from the bladder mass was reported as paraganglioma. MIBG scan was negative. Hence, he was advised DOTA scan followed by Lutetium therapy but was discharged at request. CECT venous phase axial image shows a large, lobulated moderately enhancing mass involving the base, posterior and right walls of the urinary bladder. Coronal section shows central calcification and a mixed lytic-sclerotic metastasis in the left acetabulum. Multiple other lung, nodal and skeletal metastases were present.

Literature review - location Extra-adrenal paragangliomas can be found in every site in which healthy paraganglia are known to occur Majority are seen in relatively predictable regions of the body: 1.Carotid body, 2.Jugular foramen, 3.Middle ear, 4.Aorticopulmonary region, 5.Posterior mediastinum, and 6.Abdominal paraaortic region including Zuckerkandl’s body.

Literature review - imaging Nearly identical imaging features: CT: homogeneous or heterogeneous hyperenhancing soft-tissue mass MRI: multiple areas of signal void interspersed with hyperintense foci (salt-and-pepper appearance) within tumour mass Angiography: intense tumour blush with enlarged feeding arteries

Conclusions of our study CT and MRI are the mainstay modalities of diagnosis Over 80% are in the head and neck and over half of these are carotid body tumours Majority of the lesions are between 3 and 6cm Carotid body tumours are larger at presentation and more often excised than other head & neck paragangliomas, while the latter are more often treated with embolisation, radiotherapy and stereotactic radiosurgery.

Radiological imaging is always indispensible and often sufficient for the diagnosis of extra-adrenal paragangliomas and an attractive option for treatment of the same References: Extraadrenal Paragangliomas of the Body: Imaging Features AJR 2006; 187:492–504 Radiopaedia All images are from our own institutional PACS