[Hypopharynx and larynx basaloid squamous carcinoma: our experience with 6 cases]

Basaloid squamous carcinoma (BSC) of the head and neck is an uncommon, recently described variant of epidermoid carcinoma. BSC appears biologically with a greater propensity to local aggressiveness and metastatic potential than the conventional type.

To determine the incidence of BSC of the larynx and hypopharynx in our area, and to evaluate its behavior and prognosis.

272 cases of squamous carcinoma of the larynx and hypopharynx were reviewed and 6 diagnosis of BSC were made, corresponding to 6 tumors in 5 patients. Their clinical records were analyzed. An immunohistochemical study was performed, including antibodies against cytokeratins (CK 7, CK 8, CK 19, CK 20, CK 1, 10, 5, 14, y CK 10), epithelial markers (EMA, CEA, Ber-EP4), vimentin and three neuroendocrine markers: neuron-specific enolase, chromogranin and synaptophisin. Bcl-2 expression was also investigated.

Most tumors were supraglottic. 5 out of 6 tumors were clinically benign, without any metastases or recurrence after exclusive surgical resection and a follow-up ranging 42 to 142 months. We detected a trend toward a primitive pattern of keratin expression. All tumors were stained with EMA and CEA MoAbs, but we could not find Ber-EP4 nor endocrine markers staining in any of them. However, BCL-2 expression was widely found in 4 out of 5 tumors immunostained.

It seems to be a progressive dedifferentiation of the basaloid cell component, probably a subpopulation with more primitive features responsible of the aggressiveness reported in the literature. However, the surprising good prognosis in most of our cases makes necessary more studies and wider series to confirm our data.