[Spiradenocarcinoma, cylindrocarcinoma and spiradenocylindrocarcinoma: a clinicopathological study of seven cases].

Objective: To investigate the clinicopathological characteristics of spiradenocarcinoma, cylindrocarcinoma, and spiradenocylindrocarcinoma, and to understand the correlations between their morphological patterns and clinical behaviors. Methods: Seven cases of spiradenocarcinoma, cylindrocarcinoma, and spiradenocylindrocarcinoma diagnosed at Fudan University Shanghai Cancer Center, Shanghai, China from 2015 to 2021 were collected. The clinicopathological characteristics and follow-up data were retrospectively analyzed. Histopathologic evaluation and immunohistochemical studies were carried out. Results: There were four men and three women in the cohort, with ages ranging from 46 to 75 years (mean, 61 years). The tumors were located on the head and neck (four cases), extremities (two cases), and trunk (one case). Histologically, the residuum of a benign neoplasm was present in all cases. One case presented salivary gland-type basal cell adenocarcinoma-like pattern, low-grade (BCAC-LG). Another case showed salivary gland-type basal cell adenocarcinoma-like pattern, high-grade (BCAC-HG). The remaining five cases were invasive adenocarcinoma, not otherwise specified (IAC-NOS). One of IAC-NOS contained a mucinous adenocarcinoma component. Immunohistochemically, BCAC-LG and BCAC-HG predominantly expressed basal cell markers such as p63 and p40, whereas IAC-NOS primarily exhibited positivity for CK7, a glandular epithelial marker. Follow-up was available for six patients, ranging from 1 to 9 years (mean, 4.5 years). Among the four patients of IAC-NOS with follow-up, three showed recurrences, two had regional lymph node metastases, and one died. Conclusions: The malignant components of spiradenocarcinomas, cylindrocarcinomas, and spiradenocylindrocarcinomas in this cohort contain BCAC-LG, BCAC-HG and IAC-NOS. This study also shows the presence of mucinous adenocarcinoma components in IAC-NOS. The tumors with IAC-NOS have a relatively poorer prognosis than those without.