Right upper lobe intrapulmonary mature cystic teratoma. An unusual location with unusual associations and a review of the literature

Introduction: Teratomas are rare neoplasms made up of mature embryonic germ cell layers. Extra-gonadal teratomas are rare and primarily in the mediastinum. Mature cystic teratomas (MCT) are slow-growing benign tumors accounting for a small number of mediastinal germ cell tumors. Patients with MCT are often asymptomatic, and even most symptomatic intrapulmonary teratomas present with vague and non-specific symptoms such as cough, hemoptysis, and chest pain. Case presentation and discussion: A Yemeni patient presented for two years with dry cough, shortness of breath, and stitching right-sided chest pain. Plain X-ray showed pleural thickening associated with two opacities in the right lung- one located centrally in the upper lobe and another peripherally- which were confirmed with a CT scan. During right-sided decortication with resection of the two masses, extensive adhesions were found between the right pleura and the chest wall. The adhesions were released, and right-sided decortication led to the removal of the peripheral cystic mass attached to the pleura. Histopathology reported the presence of squamous epithelium lining with ectodermal components such as hair follicles, sebaceous glands, keratin debris, fatty, and fibromuscular tissue. Conclusion: Intrapulmonary teratomas are rare tumors, with less than 100 cases reported in the past few years. All the reported cases are in the left lung lobes, yet our case is on the right side. Although the right-sided mature cystic teratoma is even scarcer, physicians should have a high index of suspicion for teratoma when encountering abnormal lesion in the right side of the lung confirming it either by CT or MRI.