Basaloid squamous cell carcinoma: Report of two rare cases and review of literature

Abstract

Basaloid squamous cell carcinoma (BSCC) is a histologically distinct variant of SCC in the head-and-neck region it occurs most commonly in older men with a history of heavy smoking and alcohol abuse and usually presents as a high stage disease with widespread metastases and hence poor prognosis. BSCC is believed to arise from a totipotential primitive cell in the basal layer of the surface epithelium or from the salivary duct lining epithelium. BSCC is an uncommon tumor with a predilection for the upper aerodigestive tract, is a distinct variant of squamous carcinoma, due to its unique histological features and ominous clinical behavior. In the oral cavity, BSCC has a predilection for the tongue, followed by the floor of the mouth, palate, buccal mucosa, retromolar trigone and gingiva. In the oral cavity, retromolar trigone/gingiva is very rare sites and only a few cases have been reported in the literature. This paper reports an additional two cases of BSCC, one reported in the retromolar region and other reported on the gingiva.

Keywords: Basaloid squamous cell carcinoma; gingiva; retromolar trigone; squamous cell carcinoma.

Figure 1

(a) Patient presenting erythematous swelling on mandibular anterior region. (b) Intra-oral photograph showing swelling on mandibular anterior gingiva

Figure 2

(a) Photomicrograph showing neoplastic cells infiltrating into the underlying stroma in the form of islands and nests (H&E, ×10). (b) Photomicrograph showing palisading pattern of peripheral cells in tumor islands. Individual tumor cells revealed hyperchromatic nuclei with scanty cytoplasm (H&E, ×40)

Figure 3

(a) Patient presenting mild facial asymmetry on right side of the face. (b) Intra-oral photograph showing erythematous ulcer extending from second premolar to retromolar pad

Figure 4

Photomicrograph showing palisading pattern of peripheral cells in tumor islands. Individual cells show hyper chromatic and pleomorphic nucleus (H&E, ×40)

Figure 5

Case 1 H&E images: Photomicrograph showing neoplastic cells infiltrating into the underlying stroma in the form of islands and sheets (H&E, ×4); Inlets in ×4 image- inlets reveal basal palisading pattern (×40), comedo necrosis (×10) and predominent basaloid cells over squamous cells (×40)

Figure 6

Case 2 H&E images: Photomicrograph showing neoplastic cells infiltrating into the underlying stroma in the form of islands and nests. (H&E, ×4]; Inlets in ×4 image- inlets reveal basal palisading pattern (×40) & comedo necrosis (×10) and predominent basaloid cells over squamous cells (×40)

Figure 7

(a and b) Photomicrograph of immunohistochemical images of 34 βE12 showing positivity for the tumor (×10 and ×40),

Figure 8

(a and b) Photomicrograph of immunohistochemical images of CK17 showing positivity for the tumor (×10 and ×40)