A Reappraisal of Superficial Pleomorphic Liposarcoma

Abstract

Objectives Superficial pleomorphic liposarcoma (PL) has a favorable prognosis compared to deeply seated PL. Given developments in the classification of lipomatous neoplasms, we reappraised a series of cases. Methods Retrospective clinicopathologic evaluation and genome-wide single-nucleotide polymorphism (SNP) microarray studies were performed for cases previously designated superficial PL. Results Four cases were identified (age, 48-70 years). Two were dermally confined, whereas two were superficial subcutaneous; no recurrences or metastases were reported. Tumors demonstrated pleomorphic spindled morphology with variable cellularity. Multivacuolated atypical lipoblasts were focal in 3 and abundant in 1. Dermal tumors demonstrated atypical cells within sclerotic collagen. Genome-wide SNP microarray studies revealed consistent gains and losses, including losses at the 13q14.2 locus encompassing RB1 and DLEU2 and deletion/disruption of the TP53 locus. Although subcutaneous examples showed genomic changes similar to deep PL, the dermal examples showed fewer genetic alterations, including changes reported in the spectrum of atypical spindle cell/pleomorphic lipomatous tumors (ASPLT). All lacked MDM2 amplification. Conclusions Careful integration of histologic and genetic features may improve classification of lipomatous neoplasms with atypia, allowing reclassification of some superficial PL as ASPLT.

Deleted in lymphocytic leukemia 2 (DLEU2): a possible biomarker that holds promise for future diagnosis and treatment of cancer

“…More recently, DLEU2 has been reported to be abnormally expressed in many malignant tumors. For example, DLEU2 is downregulated in chronic lymphocytic leukemia (CLL) [ 6 ], pleomorphic liposarcoma (PL) [ 9 ], Pseudoangiomatous Pleomorphic/Spindle Cell Lipoma [ 10 ], pediatric AML [ 8 ], and breast cancer (BC) [ 11 ]. However, most reports have shown upregulation of DLEU2 in cancers, including endometrial cancer(EC) [ 12 ], renal clear cell carcinoma(ccRCC) [ 13 ], esophageal cancer (ESCA) [ 14 ], pancreatic cancer (PC) [ 15 ], glioma [ 16 ], gastric cancer(GC) [ 17 ], non-small cell lung cancer (NSCLC) [ 18 ], thyroid cancer(TC) [ 19 ], and prostate cancer (PCa) [ 20 ].…”

Molecular testing of soft tissue tumors

“…Pleomorphic liposarcoma is a high‐grade sarcoma containing pleomorphic lipoblasts. Similar to pleomorphic lipomas and atypical pleomorphic lipomatous tumors, pleomorphic liposarcomas may have loss of the RB1 gene in superficial tumors, which is best assessed via Rb IHC 167 . They do not harbor MDM2 amplification, but TP53 is often disrupted, resulting in aberrant expression by IHC 168 …”