basaloid squamous cell carcinoma ( bscc ) as defined by the world health organization is an aggressive , high - grade , variant of squamous cell carcinoma ( scc ) composed of both basaloid and squamous components .
the tumor arises most frequently in the head and neck region , the most common sites being epiglottis , piriform sinus and base of the tongue .
other less common sites of origin include the floor of the mouth , oral mucosa , palate , tonsils , sinonasal tract , nasopharynx and trachea .
head and neck bscc tends to have an aggressive clinical course than stage - matched conventional scc .
we report two cases of bscc , one in the floor of the mouth and the other arising on the lateral border of the tongue .
a 54-year - old male patient reported to the department with a complaint of burning sensation and diffuse pain under the tongue since last 8 months [ figure 1 ] .
on examination , an ulceroproliferative growth of size 3 cm  2 cm , with indurated margins , on the anterior floor of the mouth in relation to 31 , 32 , 41 and 42 regions was noticed .
the lesion was tender on palpation . left submandibular lymph nodes were palpable , nontender and mobile .
incisional biopsy was performed and histopathology revealed a moderately collagenous connective tissue stroma infiltrated with nests and islands of tumor epithelial cells .
the tumor cells exhibited a basaloid appearance with hyperchromatic nuclei and scanty cytoplasm and were arranged in a lobular configuration .
numerous mitotic figures were also noticed amidst the tumor cells [ figures 2 and 3 ] .
photograph showing the ulceroproliferative lesion with indurated margins in the floor of mouth photomicrograph showing nests and islands of infiltrating basaloid cells .
occasional squamous differentiation is also seen ( h&e stain , 40 ) photomicrograph showing basaloid cells with nuclear atypia .
large number of mitotic figures are also noted ( h&e stain , 400 ) a 57-year - old male patient reported with the complaint of ulcer of 1-month duration on the lateral aspect of the tongue .
he reported a habit of tobacco smoking for more than 15 years . on examination , an ulceroproliferative growth of size 2
cm  2 cm on the left lateral border of the tongue , covered by necrotic slough was noticed [ figure 4 ] .
incisional biopsy was performed and histopathological examination revealed a dysplastic stratified squamous epithelium infiltrating into underlying moderately collagenous connective tissue [ figure 5 ] .
occasional areas also showed a peripheral palisading of cells and comedo necrosis [ figure 6 ] .
photomicrograph showing an ulceroproliferative lesion on lateral border of tongue with necrotic slough and indurated margins photomicrograph showing dysplastic stratified squamous epithelium infiltrating into the connective tissue .
basaloid appearance of the tumor cells and comedo necrosis can also be appreciated ( h&e stain , 40 ) photomicrograph showing tumor cells with high nuclear - cytoplasmic ratio and peripheral palisading ( h&e stain , 100 )
a 54-year - old male patient reported to the department with a complaint of burning sensation and diffuse pain under the tongue since last 8 months [ figure 1 ] .
on examination , an ulceroproliferative growth of size 3 cm  2 cm , with indurated margins , on the anterior floor of the mouth in relation to 31 , 32 , 41 and 42 regions was noticed .
the lesion was tender on palpation . left submandibular lymph nodes were palpable , nontender and mobile .
incisional biopsy was performed and histopathology revealed a moderately collagenous connective tissue stroma infiltrated with nests and islands of tumor epithelial cells .
the tumor cells exhibited a basaloid appearance with hyperchromatic nuclei and scanty cytoplasm and were arranged in a lobular configuration .
numerous mitotic figures were also noticed amidst the tumor cells [ figures 2 and 3 ] .
photograph showing the ulceroproliferative lesion with indurated margins in the floor of mouth photomicrograph showing nests and islands of infiltrating basaloid cells .
occasional squamous differentiation is also seen ( h&e stain , 40 ) photomicrograph showing basaloid cells with nuclear atypia .
a 57-year - old male patient reported with the complaint of ulcer of 1-month duration on the lateral aspect of the tongue .
he reported a habit of tobacco smoking for more than 15 years . on examination , an ulceroproliferative growth of size 2
cm  2 cm on the left lateral border of the tongue , covered by necrotic slough was noticed [ figure 4 ] .
incisional biopsy was performed and histopathological examination revealed a dysplastic stratified squamous epithelium infiltrating into underlying moderately collagenous connective tissue [ figure 5 ] .
occasional areas also showed a peripheral palisading of cells and comedo necrosis [ figure 6 ] .
photomicrograph showing an ulceroproliferative lesion on lateral border of tongue with necrotic slough and indurated margins photomicrograph showing dysplastic stratified squamous epithelium infiltrating into the connective tissue .
basaloid appearance of the tumor cells and comedo necrosis can also be appreciated ( h&e stain , 40 ) photomicrograph showing tumor cells with high nuclear - cytoplasmic ratio and peripheral palisading ( h&e stain , 100 )
first described by wain et al . in 1986 in the upper aerodigestive tract ( uadt ) ,
bscc is a rare , aggressive variant of scc with varying proportions of basaloid and squamous components .
it represents 2% of head and neck cancers with an increased tendency to be multifocal , deeply invasive and metastatic even at the initial presentation .
tobacco , alcohol abuse and a previous history of radiation to the head and neck region are considered as strong risk factors . although both of our patients failed to give a history of previous irradiation or alcohol consumption , they were chronic tobacco chewers ( betel leaf , areca nut , slaked lime and tobacco ) with occasional smoking .
the role of viruses in the etiology of bscc is still controversial , but many authors have reported a higher frequency of human papillomavirus and herpes simplex virus in basaloid tumors than in conventional scc . the origin for bscc has been suggested to be from a totipotent cell capable of divergent differentiation located in the basal zone of the surface epithelium or in the minor salivary glands of the submucosa .
some authors also believe that  basaloid  pattern occurring anywhere in the body represents an attempt at glandular differentiation .
bscc usually presents as a centrally ulcerated mass with extensive submucosal induration , often being confused with a minor salivary or soft tissue tumor .
histologically , it is considered to be a bimorphic variant of scc , with basaloid cells and an scc component which can be either in situ carcinoma or invasive keratinizing scc .
the closely packed basaloid cells growing in a solid pattern with a lobular configuration often exhibit prominent peripheral palisading and comedo - type necrosis .
this was not discernible in our cases , most probably due to small size of the specimen received .
distinctive features of bscc , not found in scc , are small cystic spaces containing periodic acid - schiff and alcian blue positive material and stromal hyalinization .
reported that wain 's criteria ( peripheral palisading , association with scc , high nuclear - cytoplasmic ratio , high mitotic rate and solid growth ) , anti-34be12 and ck 5/6 staining and absence of neuroendocrine markers are mandatory for the diagnosis of bscc .
the immunoprofile of bscc shows consistent positive staining to high molecular weight cytokeratin antibody 34e12 , kl1 , p63 and mnf116 , and focal staining for vimentin , ema , cam5.2 , ck7 , cea , s100 and gfap and negative immunostaining for ck20 , chromogranin , synaptophysin , bcl2 and ber - ep4 .
the histopathological differential diagnosis for bscc includes solid variant of adenoid cystic carcinoma ( acc ) , small cell neuroendocrine carcinoma ( scnc ) , adenosquamous carcinoma , basal cell adenocarcinoma , salivary duct carcinoma and basal cell ameloblastoma .
bscc can be differentiated from acc by the absence of myoepithelial cells , the presence of basement membrane  such as material positive for laminin and type iv collagen in the microcystic spaces , dot - like vimentin expression and negative ck7 staining .
moreover , acc shows no dysplasia or continuity with the surface epithelium and often shows less pleomorphism , mitosis and necrosis than bscc .
emanuel et al . reported that p63 immunostaining constitutes a specific and accurate means of distinguishing bscc from acc with diffuse p63 positivity and staining of nearly 100% of tumor cells in the former and a consistently compartmentalized pattern within tumor nests in the latter . to differentiate bscc from scnc ,
it is important to note that scnc shows characteristic nuclear molding , crushing artifact , lack of stromal mucinous - myxoid changes and hyalinosis and is rarely connected to the surface mucosa .
furthermore , bscc is negative for chromogranin , synaptophysin and glial - fibrillary acid protein .
the recognition of mucin positivity and true ductul - acinar differentiation in adenosquamous carcinoma differentiates it from bscc .
focal necrosis and squamous differentiation usually seen in bscc are not seen in basal cell adenocarcinoma .
eosinophilic cytoplasm and irregular - shaped cystic spaces lined by papillary projections seen in salivary duct carcinomas help to distinguish them from bscc . since the tumor shows a propensity for early metastases to regional lymph nodes and visceral locations , a multimodality treatment approach including radical surgical excision , neck dissection , radiotherapy and often chemotherapy is preferred .
distant metastasis involving the lung , bone , skin and brain develops in up to 44% of cases and is six times higher in cases of bscc compared to scc .
suggests that since lungs is the most frequent site of bscc metastasis , all patients diagnosed with bscc of the uadt systematically should undergo a chest computed tomography scan to rule out the lung metastasis and a 2-deoxy-2-fluoro - d - glucose  positron emission tomography to detect the presence of extrapulmonary asymptomatic metastatic lesions . despite more aggressive therapy , bscc
the parts of dysplastic squamous epithelium infiltrating into connective tissue were evident and the tumor cells showed a basaloid appearance with peripheral palisading , comedo necrosis and occasional squamous differentiation , which prompted us to give a final diagnosis of bscc . although the clinical diagnosis is simply that of an oral scc ( oscc ) , it should be a routine to diagnose the case histologically as any of its variants .
the diagnosis of these cases as bscc is essential as the lesion has a different clinical course , prognosis and treatment aspects when compared to the conventional oscc .
since the tumor is almost always associated with an aggressive course and poor prognosis , once diagnosed with bscc , the patient should be extensively worked up to rule out the occurrence of subclinical metastatic lesions .
the possibility of finding a second primary tumor in any site should also be kept in mind .
 basaloid squamous cell carcinoma ( bscc ) is an aggressive , high - grade , variant of squamous cell carcinoma ( scc ) , which is uncommon in the oral cavity but slightly more common in the oropharynx . 
 we present two cases of bscc , one arising in the floor of the mouth and the other arising on the lateral border of the tongue . 
 the diagnosis of this subtype of scc is important owing to its particular behavior , with an aggressive course , a high incidence of local recurrence , regional lymph node metastases and mortality rate . 
INTRODUCTION
CASE REPORTS
Case 1
Case 2
DISCUSSION
CONCLUSION
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