Primary paraganglioma of the lung: A case report

Th e patient was referred to a multidisciplinary thoracic tumor clinic, where an open lung biopsy was performed to resolve the case. Open lung biopsy and histopathological examination of the biopsied specimen revealed primary pulmonary paraganglioma ( PPP). Th e oncologist started cyclophosphamide chemotherapy for follow-up. Case presentation An 18-year-old female patient, with no special habits, presented with left neck swelling along with low-grade fever and generalized fatigue. Otherwise her clinical examination was unremarkable.

Th e patient had three lesions, the most accessible one being in the neck. A true cut biopsy was performed, which showed a scattered muscle and collagen fi bers in a bloody background. CT-guided fi ne needle aspiration from the pulmonary nodule was attempted, which failed.
Th yroid isotope scanning was performed, revealing a cold nodule (Fig. 3). Hemithyroidectomy was carried out as it is known that cold nodules have greater risk of malignancy. Th e pathology showed goiter with no activity or malignancy.
Th e patient was referred to a multidisciplinary thoracic tumor clinic, where an open lung biopsy was performed to resolve the case. Open lung biopsy and histopathological examination of the biopsied specimen revealed primary pulmonary paraganglioma ( PPP). Th e oncologist started cyclophosphamide chemotherapy for follow-up.

Case presentation
An 18-year-old female patient, with no special habits, presented with left neck swelling along with low-grade fever and generalized fatigue. Otherwise her clinical examination was unremarkable.
All laboratory investigations were normal and her tuberculin test was negative. Neck ultrasonography was performed before biopsy of the neck swelling to exclude any relation to nearby vascular structures. A right lobe thyroid nodule was indicated, and therefore a thyroid profi le was performed, which was normal.
A routine chest roentgenogram was performed, which revealed multiple pulmonary nodules ( Fig. 1). Computed tomography (CT) fi ndings confi rmed the presence of multiple nodules close to the pulmonary vasculature ( Fig. 2).

Primary paraganglioma of the lung: A case report
Tamer Ibraheem a , Hisham ElGhazaly b , Ashraf Madkour a , Ahmed Elnori c Background Primary pulmonary paraganglioma is an uncommon neuroendocrine tumor of the lung, mostly discovered accidentally.

Case presentation
We present the case of an 18-year-old female patient with multiple pulmonary nodules discovered accidentally during investigations of another presentation. Computed tomography showed close relation of nodules to the pulmonary vasculature. Diff erential diagnoses of this case include neuroendocrine tumors (Table  1) with immunohistochemical diff erentiation (Table 2).

Conclusion
Th is case report describes a low-grade, malignant PPP that presented specifi c characteristics upon CT imaging. Th is case is helpful in understanding the defi ning morphological features of PPP evident on CT imaging that may help in the diff erential diagnosis of lung tumors. Thyroid isotope scanning, revealing a right lobe nodule.

Comment
Paragangliomas are rare neuroendocrine tumors that arise from the extra-adrenal autonomic paraganglia, small organs consisting mainly of neuroendocrine cells that are derived from the embryonic neural crest and have the ability to secrete catecholamine [1]. Th ese low-grade tumors frequently occur in the superior and inferior para-aortic region, but they have also been reported in a variety of uncommon locations, including the lung parenchyma [2].
Th e normal paraganglia consists of nests of chief cells (type 1) and sustentacular cells (type 2). Two types of paraganglioma have been reported: the fi rst consists of multiple miliary tumors, as in our case; the latter consists of parenchymal or subpleural solid tumors [1]. According to the WHO classifi cation, they are tumors belonging to the group of parasympathetic (nonchromaffi n) branchiomeric paragangliomas, known as chemodectomas. Pulmonary paraganglia are identifi ed proximal to blood vessels and nerves and are frequently located at the branching pulmonary artery [3].
PPP usually presents as asymptomatic nodules, coin lesions, or as a nonfunctioning solitary mass. Some of these patients were asymptomatic with a mass being found incidentally on routine chest roentgenogram. Symptoms are usually related to catecholamine excess or local expansion of the mass [4]. In a few cases, mild or transient elevation of blood pressure was observed, but etiology remains unclear [5].