[5][6] More than 99% of primary lung cancers are carcinoma, which are tumors composed of cells that originate from embryonic ectoderm or endoderm, or that feature epithelial characteristics or differentiation.
Carcinomas of the lung are thought to arise from the uncontrolled growth of mutated, transformed, multipotent "cancer stem cells" with epithelial characteristics or lineage.
The defective "protofilament" products apparently accumulate aberrantly, and thus form the distinctive whorled paranuclear inclusions that are characteristic of the rhabdoid cell.
[citation needed] It has been reported recently[26] that LCLC-RP can metastasize locally within the airways ("aerogeneous spread"), an uncommon mechanism of extension wherein tumor cells migrate along the lung walls and septa, but do not destroy air sacs.
[citation needed] While occasional scattered rhabdoid cell formation occurs with considerable frequency in lung carcinomas, this is not considered to be of clinical significance.
[22] Vimentin, an intermediate filament protein usually found in sarcoma, is ubiquitously (nearly 100%) expressed diffusely throughout the cytoplasm of the rhabdoid cells, and is often intermingled with CK's in their whorled inclusions.
[30] In numerous clinical trials conducted in NSCLC, several different platinum-based chemotherapy regimens have been shown to be more-or-less equally effective.
[31] Taxane-based (paclitaxel, docetaxel) chemotherapy was shown to induce a complete and sustained response in a liver metastasis in a case of LCC-RP.
[32] A recent study reported a case wherein 2 courses of adjuvant therapy with cisplatin and paclitaxel, followed by oral gefitinib, were used after complete resection.
[18] As large-volume LCLC-RP may show significant central necrosis and cavitation, prudence dictates that oncologists use extreme caution if contemplating the therapeutic use of bevacizumab, other anti-VEGF compounds, or anti-angiogenesis agents in general, which have been associated with a greatly increased risk of severe hemorrhage and hemoptysis that may be quickly fatal in cavatated pulmonary squamous cell carcinomas.
[11] Although rapidly progressive, fulminant courses seem to be the rule in this entity, long-term survival has also been noted, even post-metastectomy in late stage, distant metastatic disease.
[23] Although reliable and comprehensive incidence statistics are nonexistent, LCLC-RP is a rare tumor, with only a few hundred cases described in the scientific literature to date.
[citation needed] Although Colby and colleagues were the first to report a primary lung cancer with a rhabdoid phenotype in a paper published in 1995,[40] cells with these characteristic features had been previously noted in 1978, when they were noted to occur in a rare and extremely aggressive form of kidney cancer that appears almost exclusively in young children called "Wilms tumor".
[3] LCLC-RP were first recognized as a distinct entity under the 3rd (published in 1999) revision of the World Health Organization (WHO) lung tumor histological typing scheme.