The pancreas is surrounded by soft tissue known as the peripancreatic space (PPS). Pathologic lesions of the PPS are infrequent and have only rarely been reported in the cytopathology literature.

A retrospective review of cytopathology files at two large institutions revealed 42 cases of PPS lesions obtained by transabdominal fine needle aspiration (FNA) or endoscopic ultrasound-guided FNA over a 16-year period. Clinicoradiologic findings and follow-up information were also reviewed.

Patients ranged in age from 23-83 years (mean, 60 years) with an equal gender distribution. The major clinical presentations included pain, jaundice, nausea/vomiting, and abnormal liver enzymes. Radiographic characteristics included lymphadenopathy and cystic/solid soft tissue masses with a size range of 1.5 to 8 cm. Cytologically, 4 (9.5%) cases were nondiagnostic, 9 (21.5%) were diagnosed as benign, 4 (9.5%) were atypical or suspicious for cancer, and 25 (59.5%) were malignant. Six of 25 (24%) patients had metastasis of a prior known malignancy.

FNA of PPS masses is a rare occurrence. The majority of lesions are metastatic carcinomas from a variety of primary sites. Flow cytometry and immunoperoxidase studies are useful adjuncts to determine the tumor origin. The sensitivity of PPS aspiration for a malignant diagnosis is 90% with a positive predictive value of 100%.