Pulmonary nodules are commonly encountered in pulmonary practice. Etiologies could include infectious, inflammatory, and malignant. Placental transmogrification of the lung is an extremely rare etiology of pulmonary nodules. Such condition often presents as unilateral lesions in asymptomatic men. In general, such nodules are generally stable and grow extremely slowly. We highlight an unusual case of placental transmogrification of the lung (PLC) identified in a young female. The patient\'s bilateral nodules were larger than what has been previously cited in the literature and exhibited growth over an 8-year follow-up period.

Pulmonary hamartomas are rare tumors and are mostly found incidentally in patients investigated for other pathologies. They are frequently small in size, though with some being reported as large as 25 centimeters (cm). We are reporting a case of a huge pulmonary hamartoma (measuring 25.5 × 17.5 × 15.5 cm and weighing about 2200 grams (g)) in a 33-year-old lady with a short duration history of breathlessness. The tumor had origin from the medial border of the left lung, extending into almost the entire left hemithorax and partly into the anterior mediastinum, with no local invasion. The left lower lobe had compression atelectasis due to mass. The mass was successfully resected. The histopathology report showed predominant adipose tissue and cartilaginous differentiation. There were also a few foci of papillary projections with predominant vascular areas, resembling immature placental villi, suggestive of placental transmogrification of the mass.

We report a 33-year-old man who presented with recurrent right pneumothorax. Computed tomography (CT) showed the presence of a large bulla with a maximum diameter of 8 cm in the right middle lobe; he subsequently underwent bullectomy. Histopathology revealed that pulmonary parenchyma adjacent to the bulla represented nodular proliferation of clear cells characterized by a papillary structure resembling placental chorionic villi. Immunohistochemically, clear cells were positive for CD10, suggesting placental transmogrification of the lung (PTL). We reviewed 36 surgical cases of PTL, and only 2 cases (5.6%), including our case, were operated for spontaneous pneumothorax. Bullous lesions secondary to PTL tend to appear as unilateral large cystic masses in non-upper lobes, which is atypical for primary spontaneous pneumothorax (PSP). Although PTL is considered a very rare cause of secondary pneumothorax, we must carefully differentiate this condition.

A 14-year-old male who presented with back pain was found to have giant cystic lesions on CXR and emphysematous changes on chest CT. He underwent right lobectomies and histopathology of the resected lesions demonstrated giant bullous emphysema with placental transmogrification. This has not been previously described in a pediatric patient. We describe his clinical findings, pulmonary function tests, and post-operative course. The pathogenesis of placental transmogrification remains uncertain. As this is the first reported pediatric case, we propose that giant bullous emphysema with placental transmogrification should be considered in the differential diagnosis for cystic lesions in the pediatric age group.

Giant bullous emphysema with placental transmogrification is an extremely rare entity, with 30 previously reported cases. Of these reported cases, it is typically identified with varied clinical and radiological impressions, presents in young adulthood to elderly, is always unilateral, and usually involves just one lobe. Despite the unknown pathogenesis, this diagnosis carries an excellent prognosis and is curative with complete resection. The pulmonary placental transmogrification is histologically indistinguishable from placental origin. Although not necessary to utilize because of the male predominance and no reported association, immunohistochemical stains can be used to prove lung origin. We report an extremely rare case of 2-lobe involvement of giant bullous emphysema with placental transmogrification in a boy 14 years of age, who is the youngest diagnosed patient with this lung abnormality.