Aberrant nuclear/cytoplasmic localization and gene mutation of beta-catenin in classic pulmonary blastoma
: beta-catenin immunostaining is useful for distinguishing between classic pulmonary blastoma
and a blastomatoid variant of carcinosarcoma.
It has been proposed that gastroblastoma may relate better to the spindle epithelial tumor with thymuslike differentiation and the desmoplastic nested spindle cell tumor of liver rather than blastomas
There is a continuum of differentiation between pleomorphic or spindle/giant cell carcinomas, carcinosarcomas, and blastomas.
For blastomas and carcinosarcomas, surgical resection is the primary therapeutic modality.
3,4,26-30,32) Pleomorphic carcinomas (3,4) and blastomas (4,26) are most often situated in the peripheral lung, but chest wall involvement is more characteristic of pleomorphic carcinomas and may be seen in up to 25% of cases (Figure 1).
Biphasic pulmonary blastomas have both a malignant glandular component and an embryonic or "blastematous" stroma (2,4) (Figure 7).
Rounded morules of squamouslike cells with abundant eosinophilic cytoplasm are found in 43% of biphasic pulmonary blastomas.
Other than pleuropulmonary blastoma family tumor and dysplasia syndrome, a rare syndrome related to germline mutation of DICER1 gene, most intraocular medulloepitheliomas occur sporadically and are not associated with congenital malformation or cytogenic abnormality.
Ciliary body medulloepithelioma: four cases associated with pleuropulmonary blastoma--a report from the International Pleuropulmonary Blastoma Registry [published online ahead of print December 13, 2010].
2,4-11) Pulmonary blastoma is an exception in that it demonstrates an equal sex ratio and has a mean age at diagnosis of 35 years.
The 1981 World Health Organization's Histological Typing of Lung Tumours (12) recognized spindle cell carcinoma as a variant of squamous cell carcinoma; giant cell carcinoma as a variant of large cell carcinoma; and carcinosarcoma and pulmonary blastoma as miscellaneous malignant tumors.
24) In the 2004 World Health Organization classification, (1) sarcomatoid carcinomas of the lung are classified into 5 subtypes: pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma.
2) Keratin antibodies may highlight the epithelial component of carcinosarcoma but typically diffusely stain the epithelial component of pulmonary blastoma.