An Unusual Cause of Mediastinal Mass — A Case Report and Literature Review of Intrathoracic Kidney

Abstract

Posterior mediastinal mass is not an uncommon condition seen in clinical practice. It often generates anxiety among healthcare providers, as the most common cause of a posterior mediastinal mass is a neurogenic tumour which potentially can be malignant and carries serious consequences. A very rare but generally benign cause of such a mass is an intrathoracic ectopic kidney. Due to its rarity, literature on the intrathoracic kidney, its management, prognosis and complications is sparse and confined to case reports. We report a rare case of a twomonth old baby who had a chest x-ray done for a prolonged cough and was found to have a posterior mediastinal mass, which was later diagnosed to be an intrathoracic ectopic kidney. The approach to mediastinal mass and literature review of an intrathoracic ectopic kidney and its complications are also discussed.

Ectopic Intrathoracic Kidney Presenting as Recurrent Pneumonias in a 1-year-old Infant: A Case Report

“…One additional case described a 24-year-old adult patient who presented severe pneumonia and sputum with urine-like smell, whose postmortem examination disclosed an undiagnosed left ectopic thoracic kidney adjacent to a lung abscess. The remainder of cases comprised mostly asymptomatic adult patients who discovered the ectopic kidney incidentally while undergoing imaging exams [8]. Some authors have previously hypothesized that respiratory symptoms could arise from the mass effect imposed by the intrathoracic kidneys [9].…”

Intrathoracic kidney, dextroposition of the heart, right upper and middle lobe hypoplasia of lung and pulmonary hypertension

“…Intrathoracic kidney was first described by Campbell in 1930 1 . Intrathoracic kidneys constitutes less than 5% of all renal ectopias and have the lowest frequency rate in comparison to other forms of renal ectopias 2 . We are describing a case report of intrathoracic kidney in a paediatric patient.…”

Quest for the Missing Kidney in the “Treasure Chest”: Report of a Thoracic Kidney in a Child With Recurrent Diaphragmatic Hernia

“…Patients with a thoracic kidney can be asymptomatic throughout life or can present with dyspnea, flank pain, intermittent cough, and, even, a foul-smelling expectorate. 6,7 Embryologic theories such as a pleuroperitoneal fusion abnormality or the presence of delayed mesonephric involution leading to a higher level of kidney migration could explain the occurrence of the congenital thoracic kidney. 8 The differential diagnosis of a posterior mediastinal mass includes neurogenic tumor, mediastinal lymphadenopathy, descending aortic aneurysm, paraspinal abscess, and a range of pathologic esophageal processes.…”