Case Number : Case 2449 - 21 November 2019 Posted By: Saleem Taibjee

Rhabdomyosarc/melanoma/ Triton tumor are among the differentials.

Need IHC tests.

I will add epithelioid angiosarcoma to the differentials. 

A couple more images to help you perhaps. The immuno is MNF116 (pankeratin)

And here is a clinical photo.

Prostatic metastatic carcinoma?

more consistent with Sebaceous Carcinoma. 

No-one has got it yet.

there is a grenz zone with signet ring cells CK positive, is it secondary deposits

Agree with signet ring-like neoplastic cells. Given the location of the lesion, I would favor a primary signet-ring cell / histiocytoid carcinoma of the eyelid.

Metastatic Chordoma?

Yes, well done, this is primary cutaneous signet-ring cell / histiocytoid carcinoma. The eyelid involvement is characteristic, and this is the reason this is often called the 'monocle' tumour. This often present late due to the insidious thickening/infiltration of the skin. Of course, it is still imperative rule out metastatic adenocarcinoma (breast, GI tract (gastric, large intestine, pancreas), rarely endocervix and gallbladder.

From a morphology point of view, in addition to the signet-ring cells, other features include the 'stack of pennies' arrangement (see image annotation below).

As a dermatopathologist, it is useful to have a list of differentials of tumours presenting in the skin which may show signet-ring cell morphology i.e. large pale or eosinophilic cytoplasm with inclusion or vacuole which compresses the nucleus to the edge of the cell. This includes:

Adenocarcinoma (primary vs metastatic as above)

Apocrine carcinoma (axilla)

Melanocytic lesions (melanoma, naevi)

Squamous cell carcinoma

Basal cell carcinoma

Lymphoma

Today I learned something I didn't know. Thanks for sharing.

case for learning sir, thanks

Marvelous! Thanks Saleem!

Wonderful case Saleem. Very rare but it's a fashionable at meetings!