男，68岁，右股部肿物20余年。

大体：分叶状肿物一个，体积：10×6×4厘米，表面光滑附有薄包膜，切面大部淡黄夹杂灰白色，油腻感，质较韧。一处见一灰红淡黄色结节，直径4.5厘米，质细粘滑，与周围界清。

本例是个典型的多形性脂肪瘤，可见花环状多核巨细胞是其特点

倾向脂肉，图13中考虑有脂母存在

Weiss第五版中将梭形细胞脂肪瘤和多形性脂肪瘤放在一起描述，两者均强阳性表达CD34，部分脂肉也可表达CD34，但仅为灶性，且阳性较弱，可标记一下

请问何为脂母细胞，脂母细胞形态何样？

In its earliest stages, after 10–14 weeks' gestation, it consists of aggregates of mesenchymal cells that are condensed around proliferating primitive blood vessels.Following this stage, the stellate-shaped preadipocytes are organized into lobules that contain a rich network of proliferating capillaries. At later stages (14–24 weeks' gestation), small oil red O-positive and sudanophilic lipid droplets appear in these cells, gradually converting them to rounded or spherical, multivacuolated lipoblasts. Intracellular glycogen is usually present at this stage of development. The multiple lipid droplets then fuse to form a single vacuole and displace the nucleus marginally, forming the mature fat cell, or lipocyte.
脂肪细胞的发育过程：原始的间充质细胞——星状的前脂肪细胞——圆形或球形多空泡脂肪母细胞——空泡融合形成成熟的脂肪细胞
成熟脂肪细胞以前的阶段都可以称之为脂肪母细胞，但仅多空泡脂肪母在光镜下容易识别