Dedifferentiation in adenoid cystic carcinoma
A 45-year-old female patient reported to the dental clinic with a complaint of swelling over the palate since 6 months. The patient had reported a couple of years back with a similar swelling at the same site which was diagnosed as minor salivary gland carcinoma 5 years back.\nIntra-oral examination revealed a large lobulated mass 4.5 × 3 cm in dimension. The swelling was covered by smooth stretched oral mucosa, appearing reddish at areas. Swelling extends from the midline of the palate to the gingiva of 22-27, mediolaterally and from 11-27 anteroposteriorly. The lobulated mass was soft to firm in consistency, causing discomfort but no pain.\nRadiograph revealed areas of bone erosion and destruction of the palate. Surgically, the lesion was quite vascular, was ill-circumscribed and soft to firm in consistency.\nMicroscopically, connective tissue stroma composing of lesional cells arranged in cords, nests, islands, cribriform pattern and in ductal structures with central eosinophilic coagulum was seen []. Classical areas of tumor cells arranged in epimyoepithelial islands were evident []. Areas of perineural and perivascular invasion were noted []. The neoplastic cells appeared uniform and basaloid with hyperchromatic nuclei. However other lesional areas showed solid transformation of the numerous cords, nests, islands and cribriform areas []. Some islands showed squamous metaplasia-like areas []. Areas were seen undergoing adenocarcinomatous change with basaloid tumor cells arranged in anastomosing cords with intervening thin fibrovascular connective tissue [].\nAreas of cribriform pattern [], cords, tubules, nests and islands along with solid areas showed evidence of dedifferentiation, composed of large anaplastic cells having more amount of cytoplasm. Both hyperchromatic and vesicular nuclei with prominent nucleoli could be easily cited[Figures and ]. Typical and atypical mitotic figures were evident []. Some solid tumor islands also exhibited central comedo necrosis [].