Case Number : Case 2201 - 15 November 2018 Posted By: Raul Perret

My spot is Spindle Cell Lipoma. But, im gonna need a CD34 and MUC4 to confirm because the location its quite odd.

agree with spindle cell lipoma

Agree with spindle cell lipoma. Yes, the location is a little bit odd. If it's on the shoulder or back, I would sign out as spindle cell lipoma without any immunohistochemical studies. But since the location is odd and it's a little bit more superficial, I would add Desmin and ER to CD34 because it's very difficult to distinguish spindle cell lipoma from mammary-type myofibroblastoma based purely on morphology, although they may be related genetically because they both show loss RB1, I think. But I don't do molecular so I don't really know.

Sorry. I don't know why I wrote MUC4.

Its CD34 and RB1 as Anh mentioned. 

Yes. SCL. 

Yes my diagnosis was spindle cell lipoma but explained that there was a morphological overlap with mammary type myofibroblastoma. Desmin was not expressed which is less in favour of mammary type myofibroblastoma. Nevertheless,  both of these tumors and cellular angiofibroma are closely related.