Case Number : CT0119 Adam_Bates

Paget disease. DD pagetoid melanoma. In situ squamous cell carcinoma. Porocarcinoma
 

I would add an epidermotropic lymphoma to the differential.
 

Paget's disease. DD: Pagetoid melanoma. Bowen's disease.
 

As Dr McKee advised us before I will think in terms of DDx: Melanoma with pagetoid melanocytes. Less likely: Paget's disease, Bowen's disease.
 

Good differential diagnoses
 

Beautiful case. Great pic. I agree with diagnoses and think pajets and melanoma are high up on my list. Langerhans cell histioctosis, sebaceous carcinoma and pajetoid reticulosis also show similar picture.
 

Pajets versus MM. It is helpful to see the basal layer to differentiate between the two.
 

I see assymetrical proliferation of atypical melanocytes,many of them are pagetoid,so pagetoid melanoma is my spot diagnosis
 

Favour Paget's disease, but can't rule out an epidermotropic metastatic carcinoma or melanoma.
 

pagetoid squamous cell carcinoma
 

Well, what is there left for me to say? You all did well covering the list of differential diagnoses. The diagnosis on this field is impossible without immunohistochemistry. The final diagnoses however was extra-mammary Paget's disease