Cytologic features of angiosarcoma in fluid specimens: A retrospective study of 22 cases

Background

Although histologic and fine-needle aspiration cytologic features of angiosarcoma are well established, little is known about its cytologic features in fluids. This study presents the cytomorphologic features of 22 patients who had angiosarcoma involving pleural, pericardial, ascites, and liver cyst fluids.

Methods

Patient data, including clinical histories, radiology, pathology, treatments, and follow-up, were collected.

Results

Twenty-two angiosarcoma fluid specimens (pleura, n = 17; pericardium, n = 2; ascites, n = 2; and liver cyst, n = 1) were identified. All patients had prior angiosarcoma diagnoses, and 10 (45%) had prior radiation exposure. Cellularity varied, with low cellularity predominant (73%). Cytologic architecture typically consisted of clusters of epithelioid cells (91%), single epithelioid cells (55%), and spindled cells (36%). Malignant nuclear characteristics, such as irregular nuclear membranes, chromatin clumping, and prominent nucleoli, were consistent (100%). Vasoformative features included endothelial wrapping (73%), intracytoplasmic lumina (18%), hemophagocytosis (9%), and intracytoplasmic lumina with cells (5%). Low cellularity samples usually lacked vasoformative features (27%). Prominent nucleoli, often with multiple or club-shaped forms, appeared in all cases (100%). Atypical mitotic figures (45%), associated fibromyxoid material (14%), and possible necrosis (5%) were also observed. The interval between cavity fluid involvement and primary diagnosis averaged 616 days (range, 14–2778 days). The mean time from the first positive fluid to death was 141 days (range, 3–568 days).

Conclusions

Angiosarcoma in fluids is rare. Cytomorphologic features, although nonspecific, include malignant nuclear features, prominent nucleoli, atypical mitoses, and occasional vasoformative features. Accurate diagnosis necessitates a careful review of the patient's history and judicious use of immunohistochemical staining.