Table 3.

Cases with high pleural epithelial cell levels but negative cytology examinations

Subject	PECs (cells/ml)	Diagnosis	How Dx Made/Explanation
021	431	Gastric cancer	Patient had two negative cytology examinations. Eventually diagnosed with widely metastatic gastric cancer with pleural metastases
048	12,827	Renal cell carcinoma	Patient with metastatic RCC and PET-positive lesion involving the pleura
090	588	Malignant mesothelioma	Biopsy-proven malignant mesothelioma by VATS
092	668	Lung adenocarcinoma	Patient with known metastatic NSCLC with recurrent R effusion. Cytology neg × 1. Patient had PET CT on 9/27 showing focal FDG avid uptake in the L pleural margin. Primary oncologist diagnosed patient with osseous and pleural metastases
114	2,218	Lung squamous cell carcinoma	Patient with known metastatic NSCLC and evidence of pleural nodularity on CT indicating pleural metastasis
121	5,804	Lung cancer; not otherwise specified	Cytology at PENN showed rare atypical cells in a background of blood and scant cellularity, precluding a definitive diagnosis. However, an outside hospital cytology was positive for malignancy
123	343	Malignant mesothelioma	Diagnosis made by VATS

Definition of abbreviations: CT = computed tomography; Dx = diagnosis; FDG = fluorodeoxyglucose; L = left; NSCLC = non–small cell lung cancer; PENN = University of Pennsylvania; PET = positron emission tomography; R = right; RCC = renal cell carcinoma; VATS = video-assisted thoracoscopic surgery.