Case Number : Case 1742 - 31 January - Dr Uma Sundram Posted By: Guest

To close off January's Spot Diagnosis Cases we have a nice set of images from Dr Uma Sundram.

Geoff Cross - DermpathPRO Projects

Just to break the ice, I go with vulvar leiomyoma ( but I thought a lot of vulvar dermatofibroma )...

Vulvar Leiomyoma is often clinically diagnosed as Bartholin gland cyst, so this pathological diagnosis fits well on the patient's history. The epithelioid and spindle features of the cells in this case are ill demarcated and organised in dispersed fascicles between abundant collagen bands ( this pattern made me think of a dermatofibroma ). But this is the description of VL in the pertinent literature ( Requena-Kutzner Book "Cutaneous Soft Tissue Tumors" ).

So what do you guys think about?

Hey Vincenzo in this case I thought it could be an hypopigmented blue nevus / neurotized dermal nevus VS dermatofibroma as you suggested. The cells did not struck me as smooth muscle on morphology alone

I think Raul's suggestion of a hypo pigmented blue/neurotised naevus is a good one. Doesn't particularly look smooth muscle. Needs a small battery of IHC.

Thinking in the line of a nevus also, hypopigmented blue/ desmoplastic nevus

I must confess that my first thought was some myxoid fibrohistiocytic tumor or some peripheral nerve sheath tumor, but Raul’s comment on hypopigmented blue nevus convinced me. I’d echo the words of Klaus J. Busam and Raymond L. Barnhill: “Amelanotic melanocytic proliferations are more difficult to be recognized as being melanocytic in origin.”

melanocytic markers are negative and desmin is positive

We liked vulvar leiomyoma as well.