INTRODUCTION: Common causes of a solitary lung cavity are tuberculosis (TB), fungal infection, malignancy, and benign tumors such as hamartoma. Rare causes include bronchogenic cyst, sequestration, congenital lobar emphysema and congenital cystic adenomatoid malformation (CCAM). This is a case of placental transmogrification (PT) of the lung in a patient with newly discovered uterine cancer.
CASE PRESENTATION: 66-year-old woman was referred for an incidental solitary cavity found on radiographs. She had recently been diagnosed with Stage IB endometrial cancer by D&C after presenting with post menopausal bleeding. Staging CT chest/abdomen/pelvis showed a cavity in the RUL and multiple hepatic lesions suggestive of hemangiomas. The patient was asymptomatic. A work up to rule out extra uterine disease included: CT needle biopsy of a hepatic lesion which was benign, PET scan showed mild uptake of 2.1 in the rim of the cavity suggesting benign etiology, and bronchoscopy with washing and lavage done by thoracic surgery was negative for malignancy and infection. The cavity was believed to be benign so TAH/BSO was performed and she received six cycles of carboplatin and paclitaxel and intravaginal brachytherapy. Patient was then referred to the pulmonary service to follow up on the cavity. She had no history of pulmonary disease and no prior radiographic studies. She was a teacher who never smoked, rarely traveled, and lived in New York City. She denied any exposure to TB and had a negative PPD one year prior. She was taking no medications. Her physical exam was unremarkable. Repeat CT chest was done after completion of chemotherapy and compared to the initial staging CT chest 6 months prior showed stable RUL cavity. Repeat PPD test was negative. The lesion was observed over two years, during which time it slowly increased in size. After an unrevealing FNA of the cavity and unchanged PET scan, a wedge resection of the cavity was done. The pathology was pulmonary PT.
DISCUSSIONS: Pulmonary PT is a rare benign condition. The pathology of the lesion is a bulla filled with papillae similar in appearance to a placental villus and hence the name. The papillary core consists of vascular fibrous tissue lined by pneumocytes. It is described as an isolated entity or in association with other lung diseases such as emphysema, fibrochondromatous hamartomas, lipomatosis, and Swyer-James Syndrome. The etiology of PT is unknown. It may be a congenital malformation, a reaction to emphysema, an unrecognized hamartoma or due to vascular abnormalities. The radiographic presentation of PT is usually an air filled cyst or thin walled cavity which at times may be large enough to cause mediastinal shift or rupture to cause pneumothorax. It may also present as a fluid filled cyst, nodule or mass. FNA is usually non diagnostic. The diagnosis is made by surgical resection which is only required if the patient is symptomatic or there is concern that the lesion could be malignant.
CONCLUSION: PT is a rare benign cause for a solitary cystic lesion of the lung, and should be considered in the differential diagnosis. Most of the rare causes of cystic lung malformations mentioned above are benign, except for CCAM which carries the potential of malignant transformation. Therefore, observation is necessary, and surgery is only required if the lesion starts to increase in the size or the patient becomes symptomatic.
DISCLOSURE: Samer Homsi, None.