Na,K-ATPase is a target of cigarette smoke and reduced expression predicts poor patient outcome of smokers with lung cancer.

Diminished Na,K-ATPase expression has been reported in several carcinomas and has been linked to tumor progression. However, few studies have determined whether Na,K-ATPase function and expression are altered in lung malignancies. Because cigarette smoke (CS) is a major factor underlying lung carcinogenesis and progression, we investigated whether CS affects Na,K-ATPase activity and expression in lung cell lines. Cells exposed to CS in vitro showed a reduction of Na,K-ATPase activity. We detected the presence of reactive oxygen species (ROS) in cells exposed to CS before Na,K-ATPase inhibition, and neutralization of ROS restored Na,K-ATPase activity. We further determined whether Na,K-ATPase expression correlated with increasing grades of lung adenocarcinoma and survival of patients with smoking history. Immunohistochemical analysis of lung adenocarcinoma tissues revealed reduced Na,K-ATPase expression with increasing tumor grade. Using tissue microarray containing lung adenocarcinomas of patients with known smoking status, we found that high expression of Na,K-ATPase correlated with better survival. For the first time, these data demonstrate that CS is associated with loss of Na,K-ATPase function and expression in lung carcinogenesis, which might contribute to disease progression.

Ectopic decidua of pelvic lymph nodes: a potential diagnostic pitfall.

Ectopic decidua is one of several benign lymph node inclusions that have been increasingly documented in the literature, most often in postmortem examinations of pregnant woman and recently in pregnant women with cervical squamous cell carcinoma. Although lacking clinical significance of its own, the major diagnostic implication would be misdiagnosis as metastatic carcinoma in the lymph node. Intraoperative frozen sections are often performed prior to radical hysterectomy, leading to a potential alteration of therapy if metastatic carcinoma is identified in the lymph nodes. We report such a case of a pregnant woman with cervical squamous cell carcinoma requiring lymphadenectomy and hysterectomy, in which the intraoperative frozen section of a pelvic lymph node with ectopic decidual change was mistakenly identified as metastatic carcinoma. Its histologic resemblance to carcinoma and location within subcapsular sinuses, compounded with the fact that ectopic lymph node decidua is not commonly seen in routine practice, can lead to this diagnostic pitfall. We review the literature regarding ectopic decidua, its presence in lymph nodes, and its pathogenesis, as well as review the literature on benign lymph node inclusions.