Pulmonary metastasis from liposarcoma: a clinicopathologic and immunohistochemical study of 24 cases

A review of the histologic features of pulmonary metastasis and clinical implications of liposarcoma (LS) is given for 24 cases (8 each) of the 3 types of LS: myxoid LS (ML), pleomorphic LS (PL), and dedifferentiated LS (DDL). Most patients were men. Metastatic ML and PL were distributed almost equally among the lung lobes, whereas DDL was more common in the left lower lobe. The metastatic MLs had variable cellularity ranging from singly scattered cells in a hyalinized stroma (treatment-related effect) to hypercellular ML. Most PLs (6/8) were nonlipogenic and resembled an undifferentiated pleomorphic sarcoma. All metastatic DDLs had high-grade histologic features and were predictably nonlipogenic. After pulmonary metastasectomy, 2 patients with ML and 1 with PL were disease-free. The other 6 patients with ML, 7 with PL, and all with DDL had progressive disease. The morphologic features of LS metastatic to the lungs seem diverse but within the spectrum of the histologic type expected from the primary tumor. Overall, the general trend for these LS subsets is progressive disease, metastatic disease for ML and PL with a much shorter interval for PL, and metastatic disease and local recurrence for DDL.