Intrapulmonary teratoma misdiagnosed as aspergilloma

A 52‐year‐old woman presented complaining of intermittent episodes of hemoptysis for over 40 years. Chest computed tomography (CT) showed a cavitary lesion (5.5 × 5.3 cm) in the left upper lobe with heterogeneous components. The radiologic manifestations hinted a fungus ball (Fig 1a). Bronchoscopic biopsy and bronchoalveolar lavage failed to identify tumor cells or pathogens. A serum tuberculosis antibody test indicated no abnormalities. The initial diagnosis was made by a local physician as Aspergillus infection because of positive results of Aspergillus galactomannan (GM) assay. The patient was administered voriconazole (4 mg/kg, q12h) for two weeks; however, her symptoms failed to alleviate. She was transferred to our hospital and underwent left upper lobectomy via a posterolateral thoracotomy through the fifth intercostal space. The specimen revealed a solid‐cystic mass containing yellow sebaceous material, hair and skin (Fig 1b). Histopathological examination revealed a mature cystic teratoma lined by squamous epitheliums and sebaceous glands, hair follicles, mature adipose tissue, smooth muscles, cartilage and respiratory epithelium without any malignant cells. A final diagnosis of mature cystic intrapulmonary teratoma was established. Postoperatively, the patient underwent a smooth recovery and was discharged at postoperative day 4.

Figure 1.

(a) Chest computed tomography revealed a 5.5 cm mass in the left upper lobe with cavitation and an intracavitary mass at the mediastinal window (arrow). (b) A photograph of the resected specimen showing a solid cystic mass containing yellow sebaceous material, as well as some fat, hair and skin, in the lung (arrow).

Most intrathoracic teratomas were found in the mediastinum. However, intrapulmonary teratomas (IPT) are extremely rare and only a few cases have been reported in the English literature.1 Symptoms of patients with IPT are not specific. The patient might have a fever, cough, hemoptysis, chest pain or hair expectoration (trichoptysis).2 However, trichoptysis, which is the only clinical diagnostic feature, is uncommon. The radiological findings of IPTs are diverse, including a heterogeneous lobulated opacity containing soft tissue, fat, fluid, and/or calcification; and cavitation or peripheral translucency.3 Nevertheless, lesions with cavitary features, peripheral translucent areas, or an “air crescent sign” are extremely rare.3 In this case, both an “air crescent sign” in the preoperative CT scan and GM test hinted a fungus ball that led to misdiagnosis as fungus infection; however, the patient failed to respond to antifungal treatment. Surgical resection and histopathologic examination finally confirmed the diagnosis of IPT.

In conclusion, our case shows a rare manifestation of IPT. IPT can be easily misdiagnosed as a fungus ball, particularly in cases with cavitary lesions. IPT should be considered in the differential diagnosis of pulmonary cavitary lesions, even in patients with positive for GM test.

Disclosure

No authors report any conflict of interest.