Cytological features of basal cell adenoma of salivary glands: Analysis of 19 cases emphasizing stromal spindle cells

Abstract

Background Basal cell adenoma (BCA) of the salivary gland is a relatively rare benign tumor. Although the presence of stromal spindle cells is a characteristic histopathological feature, this finding has not been the focus of much attention in the cytodiagnosis of BCA. Thus, we analyzed the cytological features of BCA, especially the presence of stromal spindle cells. Methods Patients who were histopathologically diagnosed with BCA and underwent preoperative fine‐needle aspiration cytological examination were enrolled in this study. The cytological characteristics including arrangement and shape of the neoplastic cells, nuclear and cytoplasmic features, and the presence of stromal spindle cells were reviewed. Results Nineteen patients were enrolled in the study. The cytological specimens were cellular and composed of small or large clusters or both. The neoplastic cells had scant cytoplasm and small round to oval nuclei. Basement membrane‐like material was observed in 57.9%, and peripheral palisading was noted in 84.2%. Loose aggregates of stromal spindle cells were present in 63.2%, and the stromal spindle cells shown in the histological examination of 85.7% of cases were expressed in the cytological specimens. Conclusion This study clearly demonstrated the relatively high frequency of stromal spindle cells in cytological specimens of BCA. This finding is characteristic of BCA, and therefore, the combination of cytological features, including packed clusters of neoplastic cells with scant cytoplasm and small nuclei, peripheral palisading, and basement membrane‐like material, and the presence of stromal spindle cells could increase the diagnostic success of BCA.

Cytological features of basal cell adenocarcinoma of the salivary glands

“…Hara et al reported that six of nine basal cell adenoma specimens had stromal spindle cells, but these cells were not observed in BAC (two cases), adenoid cystic carcinoma (10 cases), myoepithelioma (four cases), and pleomorphic adenoma (five cases) specimens . Our previous study demonstrated that stromal spindle cells were present in the cytological specimens of 85.7% of histology‐proven stromal spindle cells‐positive basal cell adenoma cases and 63.2% of all basal cell adenoma cases . Taken together, the data indicate that stromal spindle cells are frequently present in the cytological specimens of both basal cell adenoma and BAC cases.…”

“…Stromal spindle cells are considered a characteristic feature of basal cell adenoma . Although these cells can also be present in BAC, the precise incidence of the presence of stromal spindle cells in BAC remains unclear .…”

“…4,5 Stromal spindle cells are considered a characteristic feature of basal cell adenoma. 9 Although these cells can also be present in BAC, the precise incidence of the presence of stromal spindle cells in BAC remains unclear. 10,11 In the present series, stromal spindle cells were observed in three of seven cases of BAC (42.9%), and notably, all nosis of pleomorphic adenoma.…”

“…Recently, we analyzed the cytological features of basal cell adenoma of the salivary glands, and clearly demonstrated that the detection of stromal spindle cells was very useful in the diagnosis of basal cell adenoma . Although the presence of stromal spindle cells is a characteristic feature of basal cell adenoma, these cells are also observed in some cases of BAC .…”

“…[2][3][4][5][6][7][8] Recently, we analyzed the cytological features of basal cell adenoma of the salivary glands, and clearly demonstrated that the detection of stromal spindle cells was very useful in the diagnosis of basal cell adenoma. 9 Although the presence of stromal spindle cells is a characteristic feature of basal cell adenoma, these cells are also observed in some cases of BAC. 10,11 Therefore, in this study, we reviewed the cytological features of BAC cases with respect to stromal spindle cells as well as other cytological characteristics, and discuss the cytological considerations for differential diagnosis of this tumor.…”