Congenital peribronchial myofibroblastic tumour5
Definition
A proliferation of uniform plump spindle cells in a peribronchovascular distribution.
Synonyms
Congenital fibrosarcoma4, congenital leiomyosarcoma, congenital mesenchymal malformation of the lung, neonatal pulmonary hamartoma.
Epidemiology
Less than 15 cases have been reported. There is no genetic predisposition or association with any syndrome.
Clinical features
The tumour presents during pregnancy with polyhydramnios / hydrops fetalis3,5, or shortly after birth.
Radiology
There is often an opaque hemithorax1.
Macroscopic appearances
The tumour is well demarcated but not encapsulated. The cut surface is fleshy and may show haemorrhage or necrosis. The tumour obliterates or distorts the bronchus.
Histopathology
Uniform spindle cells form intersecting fascicles1. Nuclei lack pleomorphism but mitotic activity is variable. The tumour may extend onto the pleural surface.
Immunohistochemistry
Ultrastructure
There are features of myofibroblastic differentiation.
Cytogenetics
Although the tumour resembles congenital infantile fibrosarcoma and congenital mesoblastic nephroma, there have been no reports of t(12;15)(p13;q25-26).
Differential diagnosis
Management
The involved lobe or lung requires resection.
Prognosis
Fetal hydrops may be fatal but the behaviour of the tumour is benign1,4.
References
0 Tumours of the Lung, Pleura, Thymus and Heart. WHO Classification of Tumours. IARC Press 2004.
1 Alobeid B, Beneck D, Sreekantaiah C, et al. Congenital pulmonary myofibroblastic tumor: a case report with cytogenetic analysis and review of the literature. Am J Surg Pathol 1997; 21:610-4
2 Coffin CM, Jaszcz W, O'Shea PA, et al. So-called congenital-infantile fibrosarcoma: does it exist and what is it? Pediatr Pathol 1994; 14:133-50
3 Khong TY,Keeling JW. Massive congenital mesenchymal malformation of the lung: another cause of non-immune hydrops. Histopathology 1990; 16:609-11
4 Kuhnen C, Harms D, Niessen KH, et al. [Congenital pulmonary fibrosarcoma. Differential diagnosis of infantile pulmonary spindle cell tumors]. Pathologe 2001; 22:151-6
5 McGinnis M, Jacobs G, el-Naggar A, et al. Congenital peribronchial myofibroblastic tumor (so-called "congenital leiomyosarcoma"). A distinct neonatal lung lesion associated with nonimmune hydrops fetalis. Mod Pathol 1993; 6:487-92
This page last revised 5.5.2005.
©SMUHT/PW Bishop