Overview of Lipoblasts and Mimics



Overview of Lipoblasts and Mimics


David R. Lucas, MD








Lipoblasts come in a variety of sizes and shapes. The cytoplasm is filled with lipid that appears as 1 or multiple clean, punched-out vacuoles that indent and scallop the nucleus.






Malignant lipoblasts are required to diagnose pleomorphic liposarcoma. This lipoblast has a large hyperchromatic nucleus image sharply indented by multiple lipid-filled vacuoles image.


LIPOBLASTS


Definitions



  • Lipoblasts are embryonic mesenchymal cells that develop into fat cells



    • Wide spectrum of cell morphology



      • Primitive spindle cells with small cytoplasmic vacuoles


      • Univacuolated or multivacuolated round cells


      • Signet ring cells


  • Neoplastic lipoblasts morphologically recapitulate developmental stages of lipogenesis



    • Malignant lipoblasts characterized by nuclear hyperchromasia and atypia



      • Peripheral crescentic nuclei


      • Multilobated nuclei


      • Multinucleated giant lipoblasts


Background



  • Lipoblasts are not required for diagnosing all types of liposarcomas



    • Atypical lipomatous tumor/well-differentiated liposarcoma



      • Lipoblast often present but not required for diagnosis


      • Defined by presence of atypical stromal cells


    • Myxoid/round cell liposarcoma



      • Highly variable numbers of lipoblasts present in a given tumor


      • Wide spectrum in appearance of lipoblasts


      • Univacuolated round cells, multivacuolated cells, signet ring cells


    • Pleomorphic liposarcoma



      • Identification of lipoblasts is required for diagnosis


      • Often contain very large pleomorphic and multinucleated lipoblasts


      • Lipoblasts sometimes sparse


  • Lipoblasts are not pathognomonic of liposarcoma



    • Lipoblasts can be found in benign tumors



      • e.g., lipoblastoma


      • e.g., lipoblastic nerve sheath tumor

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Overview of Lipoblasts and Mimics
Premium Wordpress Themes by UFO Themes
%d bloggers like this: