SESSION TYPE: Cancer Student/Resident Cases
PRESENTED ON: Monday, October 22, 2012 at 01:45 PM - 03:00 PM
INTRODUCTION: Gestational trophoblastic neoplasm (GTN) is a chemo-responsive malignancy that frequently involves the lung. This case highlights the diagnostic challenges associated in identifying GTN when minimal disease isolated to the lung is present.
CASE PRESENTATION: A 36 year old multiparous (G5, P2) woman presented with a bHCG of 3700 IU/L three months after a spontaneous abortion. The bHCG was checked in response to a missed menstrual cycle. She was otherwise asymptomatic with a normal physical exam. Pelvic ultrasound was negative for intra or extra-uterine pregnancy. Pathology from diagnostic laparoscopy and uterine dilatation and curettage showed benign endometrial cells. Initial investigations also included a chest x-ray which showed a well-defined 13 mm nodule in the left lower chest. However it was difficult to distinguish whether the nodule was within the lung parenchyma versus breast tissue. A breast ultrasound ruled out a soft tissue mass, however no additional investigations of the lung nodule were completed. The patient was started on methotrexate for presumed chronic ectopic pregnancy with a peak bHCG of 8027 IU/L. Despite two months of treatment, the patient's bHCG improved but did not normalize. Repeat pelvic ultrasound and exploratory laparoscopy were normal. Repeat chest x-ray showed a lobulated 16 mm cavitating nodule in the left lower lung. Chest CT did not identify an additional lesions. Biopsy of the nodule showed atypical epithelioid cells and immunohistochemistry identified the cells as trophoblasts (AE1/AE3, bHCG and Inhibin positive). The patient was started Actinomycin D chemotherapy for her diagnosis of metastatic GTN with normalization of her bHCG.
DISCUSSION: GTN refers to abnormal proliferation of trophoblasts usually derived from placenta tissue. Metastatic disease to the lungs is well established; however, less commonly reported is isolated lung pathology. Theoretically isolated lung involvement could represent a primary process such as abnormal germ cell migration or tumour cell metaplasia versus metastatic remnants of spontaneously resolved uterine disease. In this case, the temporal relationship with spontaneous abortion and lack of lung tumour markers was more suggestive of metastatic GTN; however regardless of the classification a similar therapeutic approach applies. It is the early identification of a pulmonary focus of malignant GTN which is essential to direct therapy and prevent treatment delays.
CONCLUSIONS: Pulmonary nodules may represent the only focus of disease for GTN as either a primary or metastatic process. Any abnormalities on chest x-ray identified in the context of unexplained bHCG elevation need to be evaluated thoroughly.
1) Berthod G, Bouzourene H, Pachinger C, et al. Solitary choriocarcinoma in the lung. Journal of Thoracic Oncol. 2010;5(4):574-5.
2) Seol HJ, Lee JH, Lee KY, et al. Primary pulmonary choriocarcinoma presenting as hemothorax. journal of Thoracic Oncol. 2009;4(5):663-5
DISCLOSURE: The following authors have nothing to disclose: Kirandeep Saini
No Product/Research Disclosure InformationUniversity of Calgary, Calgary, AB, Canada