Thompson et al. Journal of Medical Case Reports 2010, 4:17 http://www.jmedicalcasereports.com/content/4/1/17 event and the patient recovered rapidly and was dis- charged within a week. Subsequent histology confirmed a well-differentiated fetal adenocarcinoma of the lung with one microscopic focus of blastoma, which appeared after sectioning the entire tumour. The mediastinal glands were not involved but tumour was present at the bronchial resection mar- gin. As this tumour is not usually radiosensitive, it was decided that the remaining right upper lobe should be removed in order to affect a possible cure with the least possible chance of recurrence. Again surgery was uneventful, and she made a quick recovery. However, histology from the completion pne- monectomy suggested the possibility of microscopic residual disease around the area of the stump of the right main bronchus. The clinical oncologists suggested treatment with radical external beam radiotherapy to try to prevent disease recurrence around the bronchial stump, which she underwent with minimal side effects. A year following diagnosis, the patient is well and recurrence free. She does, however, report a persistent dry cough and breathlessness on severe exertion. Discussion Well-differentiated fetal adenocarcinoma (WDFA) is classified by the World Health Organisation as a variant of adenocarcinoma. When fetal adenocarcinoma is asso- ciated with primitive blastemal stroma, it is classified as a pulmonary blastoma. In this case, there was only a microscopic focus of blastomatous tissue, so we were not totally certain that the categorisation into blastoma was correct. Pulmonary blastoma is a rare malignant tumour comprising 0.25 - 0.5% of all primary lung tumours [1-3]. Histologically, the WDFA element char- acteristically demonstrates neoplastic glands that resem- ble fetal lung and squamoid morules with clear nuclei [1]. The immature mesenchyme and epithelium mimic the embryonic lung at 10-16 weeks gestation [2]. The name WDFA is therefore derived from the histological appearances of the tumour. There is currently no known relationship between pulmonary blastoma and pregnancy. One study has hypothesised that oestrogen may be involved in the development of pulmonary blas- toma through the oestrogen receptor-b [4], but in this case, the tumour was negative for this oestrogen receptor. The peak incidence of pulmonary blastoma is 35-40 years of age, with an equal sex distribution. 80% of patients are smokers [3]. Our patient was somewhat younger, at only 27 years of age. Although she is cur- rently a non-smoker, she had smoked for ten years prior to diagnosis. Patients may be asymptomatic or present with persistent cough, haemoptysis (as in this case) or chest pain. Page 3 of 4 The standard treatment for pulmonary blastoma is surgical resection [2,3], although there have been reports of limited success with adjuvant radiotherapy and che- motherapy [2]. The prognosis of pulmonary blastomas is poor, although compared with its biphasic counterpart, that of WDFA is better [5] (particularly when resection is complete), with a mortality rate of 14% and 52% respectively [3]. To the best of our knowledge this is the first reported case of WDFA diagnosed in pregnancy, although there has been a case of WDFA identified in a woman three months post partum [3], and one of a biphasic pulmon- ary blastoma diagnosed in pregnancy [6]. However, other types of lung carcinomas have been described in pregnancy. In most cases, the disease is reported as highly aggressive and frequently fatal. Conclusion This case of well-differentiated fetal adenocarcinoma in pregnancy demonstrates the importance of establishing an accurate diagnosis when a pregnant woman presents with haemoptysis, cough and/or chest pain. When the clinical symptoms are persistent and/or a V/Q scan pro- vides no logical explanation, it is important to seek advice from a senior respiratory physician, and consider undertaking a CTPA, both of which can play a vital role in identifying rare but life threatening lung pathology. Consent Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the journal’s Editor-in-Chief. Abbreviations CTPA: computed tomography pulmonary angiogram; LMWH: low molecular weight heparin; PET: positron emission tomography; WDFA: well- differentiated fetal adenocarcinoma. Acknowledgements We would like to thank the patient for giving her permission for her case to be presented. Author details 1Department of Obstetrics and Gynaecology, St Mary’s Hospital, Hathersage Road, Manchester M13 9WL, UK. 2Department of Histopathology, The University of Manchester, Oxford Road, Manchester M13 9PT, UK. 3School of Medicine, The University of Manchester, Oxford Road, Manchester M13 9PT, UK. 4Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK. 5Department of Respiratory Medicine, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK. Authors’ contributions LMB, PSH, PMT and MW were involved in the multidisciplinary management of this case. RJT wrote the manuscript with the help and guidance of LMB. All authors reviewed the manuscript and contributed to the discussion. Competing interests The authors declare that they have no competing interests.