Fetal adenocarcinoma of the lung (FLAC) is a rare form of adenocarcinoma of lung (falls under invasive category).
Some reports suggest its occurence at ~0.1%-0.5% of all pulmonary neoplasms 1. Despite its "fetal" tissue morphology it typically presents in middle aged to elderly patients (60 to 70 year olds 2)
It is an adenocarcinoma resembling developing fetal lung in its pseudoglandular stage (i.e. that seen at 8-16 weeks of gestation). It is considered different to a pulmonary blastoma due to a lack of a mesenchymal component
Fetal adenocarcinoma of the lung can be divided into two forms according to severity.
- low-grade fetal adenocarcinoma (L-FLAC): low nuclear atypia and prominent morule formation and has a pure pattern
- high-grade fetal adenocarcinoma (H-FLAC): often over 50% fetal morphology, and often associated with other conventional types of lung adenocarcinoma
History and etymology
It is thought to have been first described by WG Barnard in 1945 and 1952, as a biphasic tumor comprising an epithelial component surrounded by mesenchymal stroma resembling fetal lung, hence initially named as “embryoma of the lung".
- 1. Ricaurte LM, Arrieta O, Zatarain-Barrón ZL, Cardona AF. Comprehensive review of fetal adenocarcinoma of the lung. (2018) Lung Cancer (Auckland, N.Z.). 9: 57-63. doi:10.2147/LCTT.S137410 - Pubmed
- 2. Nakatani Y, Kitamura H, Inayama Y, Kamijo S, Nagashima Y, Shimoyama K, Nakamura N, Sano J, Ogawa N, Shibagaki T, Resl M, Mark EJ. Pulmonary adenocarcinomas of the fetal lung type: a clinicopathologic study indicating differences in histology, epidemiology, and natural history of low-grade and high-grade forms. (1998) The American journal of surgical pathology. 22 (4): 399-411. Pubmed
- 3. Morita S, Yoshida A, Goto A, Ota S, Tsuta K, Yokozawa K, Asamura H, Nakajima J, Takai D, Mori M, Oka T, Tamaru J, Itoyama S, Furuta K, Fukayama M, Tsuda H. High-grade lung adenocarcinoma with fetal lung-like morphology: clinicopathologic, immunohistochemical, and molecular analyses of 17 cases. (2013) The American journal of surgical pathology. 37 (6): 924-32. doi:10.1097/PAS.0b013e31827e1e83 - Pubmed
- 4. Patnayak R, Jena A, Rukmangadha N, Lakshmi AY, Chandra A. Well-differentiated fetal adenocarcinoma of the lung in an adult male: report of an unusual tumor with a brief review of literature. (2014) Journal of cancer research and therapeutics. 10 (2): 419-21. doi:10.4103/0973-1482.136677 - Pubmed
- 5. Longo M, Levra MG, Capelletto E, Billè A, Ardissone F, Familiari U, Novello S. Fetal adenocarcinoma of the lung in a 25-year-old woman. (2008) Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer. 3 (4): 441-3. doi:10.1097/JTO.0b013e318169cd9a - Pubmed
- 6. Kawai T, Miyake T, Hara K, Hara F, Nakashima T. [Pulmonary adenocarcinoma of the fetal lung type; report of a case]. (2003) Kyobu geka. The Japanese journal of thoracic surgery. 56 (4): 340-3. Pubmed