In 1982, Kradin et al. described fetal adenocarcinoma firstly as a very rare subtype of malignant lung cancer [8]. In pulmonary blastoma, sex distribution was equal and the peak incidence was (35-40 years) of age, 80% of patients are smokers [4]. These are being commonly diagnosed at an early stage without involvement of lymph node.
At the histological level, the element of WDFA characteristically shows glandular elements with tubules composed of glycogen-rich, non ciliated cells that resemble fetal lung, tubuless and squamoid morules may be seen with clear nuclei within lumens. The immature mesenchyme and epithelium mimic the embryonic lung at 10-16 weeks gestation [9, 10].
Surgical resection is the standard treatment for patients with pulmonary blastoma [4, 5], despite the fact that there have been reports of limited success with adjuvant radiotherapy and chemotherapy [5].
The prognosis of pulmonary blastomas is poor, although prognosis of WDFA is better than biphasic [11], particularly when resection is complete, with a mortality rate of 14% and 52% respectively [4].
Our understanding of fetal adenocarcinoma is derived from case reports and small series. Koss et al. reported 28 cases of WDFA, with long follow up of 95 months, and 5-year survival of 81%. Sato et al. reported 25 cases; the vast majorities has small size and were N0 at 88% of cases [11, 12]. Van Loo et al. previously reported 9 cases of WDFA there were beyond T3 stage and underwent postoperative or radiation therapy however the benefit of this treatment was unclear [13].
Our patient received 3 cycles of etoposide – cisplatin protocol. We chose this protocol because of the sensibility of fetal tumors to the combination based on etoposid and cisplatin-like nephroblastoma. Tumor response was assessed by chest CT scan after 3 cycles of CMT, and we showed 12% reduction of the tumor mass corresponding to a stable disease according to RECIST Criteria, this is due to a low proliferation of his tumor (index of proliferation, Ki-67 was 1%).
Thus the role of neoadjuvant CMT in WDFA remains unknown, but we conclude that CMT is ineffective probably because the tumor is not proliferative, however it should be noted that Zaidi [14] has reported a case of WDFA treated with neoadjuvant CMT with mitomycin, ifosfamide and cisplatin for a WDFA staged T4N0M0 in a woman of 27 years, which successfully downstaged the tumor before surgical resection, with good control at 29 months. Also Chanhee et al. reported the first case of locally advanced WDFA treated with concurrent chemoradiation therapy with docetaxel with partial response [15]. But we have no idea of the proliferation index, and the cornerstone of treatment is surgery as much as possible.
