Journal of Dental Sciences (2016) 11, 113e115
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Basaloid squamous cell carcinoma of the mandible
KEY WORDS Basaloid squamous cell carcinoma; mandible; oral cavity
Basaloid squamous cell carcinoma (BSCC) is regarded as a rare but aggressive variant of SCC in the head and neck region.1 Here, we reported a solitary BSCC located mainly in the right second and third molar region of the mandible. This 74-year-old female patient was referred to the Oral and Maxillofacial Surgery Department of a medical center in Taipei, Taiwan for extraction of the mobile right mandibular second molar and the horizontally impacted right mandibular third molar. Previous medical history revealed that the patient had hypertension and the disease was well controlled by regular medication. Intraoral examination revealed a red swelling mass at the buccal gingiva of the right mandibular second and third molar. The panoramic radiograph showed a radiolucent lesion at the periradicular area of tooth #47 and the pericoronal region of impacted tooth #48 (Fig. 1A). Under the clinical diagnosis of an inflamed dentigerous cyst, the lesion was totally removed under general anesthesia. The patient stood the procedure well. The specimen was sent for histopathological examination. Microscopically, the surface epithelium was relatively intact and an infiltrating carcinoma was found in the lamina propria (Fig. 1B). In some areas, the tumor was composed of nests of hyperchromatic basaloid cells and a few clear cells in a fibrous stroma (Fig. 1C). In other areas,
aggregates of basaloid cancer cells separated by thin fibrous septa were noted (Fig. 1D). Palisading of the peripheral cancer cells was found occasionally and cellular pleomorphsim and mitotic figures were easily detected (Fig. 1E). Immunohistochemical staining revealed that the tumor cells were positive for p63 (Fig. 1F) and cytokeratin AE1/AE3 (Fig. 1G), but were negative for cytokeratin 7, cytokeratin 20, thyroid transcription factor-1 (TTF-1), and mucicarmine (data not shown). The above mentioned microscopic features and the immunostaining results favored the diagnosis of a BSCC. A recent retrospective study showed a mean age of 66.7 years for BSCC patients and a strong predilection of the tumors for white men. In the oral cavity, the most commonly affected site was the floor of mouth (46.7%), followed by the tongue (13.0%) and retromolar trigon (13.0%). The 5-year disease-specific survival rate for BSCC patients is similar to that for oral SCC patients.1 Immunohistochemistry is a valuable technique that can be used to identify the Langerhans cells in the lining epithelium of an epidermoid cyst2 or a unicystic ameloblastoma3 and to confirm a metastatic oral malignant melanoma4 or a metastatic oral hepatocellular carcinoma.5 In this study, we used the immunostain to prove that the cancer cells were epithelial basal cells. It is still not very clear whether this BSCC is arising from the surface epithelial basal cells or from the odontogenic epithelial basaloid cells in the gingiva or jaw bones.
Conflicts of interest The authors have no conflicts of interest relevant to this article.
http://dx.doi.org/10.1016/j.jds.2016.01.001 1991-7902/Copyright ª 2016, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Figure 1 Panoramic radiograph and microphotographs of our case of basaloid squamous cell carcinoma. (A) The panoramic radiograph showed a radiolucent lesion at the periradicular area of tooth #47 and the pericoronal region of impacted tooth #48. (B) Microphotograph demonstrated a relatively intact surface epithelium and an infiltrating carcinoma in the lamina propria. (C) In some areas, the tumor was composed of nests of hyperchromatic basaloid cells and a few clear cells in a fibrous stroma. (D) Aggregates of basaloid cancer cells separated by thin fibrous septa were noted. (E) Palisading of the peripheral cancer cells was found occasionally and cellular pleomorphsim and mitotic figures were easily detected. (Hematoxylin and eosin stain; original magnification, B and D, 10; C and E, 20) Immunohistochemical staining revealed that the tumor cells were positive for p63 (F) and cytokeratin AE1/AE3 (G). (Original magnification, F and G, 20)
References 1. Fritsch VA, Gerry DR, Lentsch EJ. Basaloid squamous cell carcinoma of the oral cavity: an analysis of 92 cases. Laryngoscope 2014;124:1573e8. 2. Wu YC, Wang YP, Chang JYF, Chiang CP. Langerhans cells in lining epithelia of epidermoid cysts. J Dent Sci 2013;8: 448e50. 3. Wu YC, Wang YP, Liu YC, Chen HM. Langerhans cells in the lining epithelium of unicystic ameloblastoma. J Dent Sci 2015;10: 464e6. 4. Lu SY, Lin CF, Huang SC. Metastatic oral malignant melanoma transformed from pre-existing pigmented lesions in mandibular gingiva: report of an unusual case. J Dent Sci 2013;8: 328e32. 5. Chen HM, Wu YC, Wei LY, Chiang CP. Metastatic hepatocellular carcinoma of the anterior palatal gingiva. J Dent Sci 2014;9: 202e4.
Chieh Yuan Cheng Department of Oral and Maxillofacial Surgery, MacKay Memorial Hospital, Taipei, Taiwan
115 Chun-Pin Chiang Graduate Institute of Oral Biology and Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan Department of Dentistry, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan Hung-Pin Lin* Department of Medicine, MacKay Medical College, New Taipei City, Taiwan Department of Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan *Corresponding author. Department of Dentistry, MacKay Memorial Hospital, Taipei, Taiwan. E-mail address: [email protected]
(H.-P. Lin) Received 15 January 2016 Available online 23 February 2016