Case Number : Case 1669 - 17 November - Dr Arti Bakshi Posted By: Guest

Well this is a bit of an eyeful from Arti, what do you think?

Geoff, DermpathPRO Projects

endocrine mucin secreting sweat gland carcinoma?

I think this is a low grade mucinous carcinoma of the eyelids. Typically mammary-like and, as its mammary "colleague", may be positive to some neuroendocrine antigen. I don't know if it really is a neuroendocrine tumor, but agree with Rinad that it is a mucin secreting carcinoma, very low grade and with very poor mucin in this pictures...

I also thought of endocrine mucin producing sweat gland carcinoma.

I agree endocrine mucin producing sweat gland carcinoma

Well-circumscribed solid tumor showing lobular pattern of growth and comprising small monomorphic cells with bland-appearing round nuclei. There are signs of glandular differentiation, including intracytoplasmic lumina and mucin-containing ductal structures. Neuroendocrine differentiation is highlighted by expression of synaptophysin, albeit chromogranin is negative. Endocrine mucin-producing sweat gland carcinoma. Typically situated on the eyelid.

Great discussion so far! Have asked Geoff to post some more images...of the other half of the lesion.

Do they change your opinions?? 

New images added, enjoy...

PCMC with neuroendocrine dif but should make dd with metastasis although less likely. Article

Did you perform p63 Arti?

Mucinous carcinoma with neuroendoc diff .. exclude metastasis. 

According to Kazakov’s book, primary cutaneous mucinous carcinoma rarely shows neuroendocrine differentiation, displaying further similarity to breast neoplasms. That said, the book makes referrals to articles on endocrine mucin-producing sweat gland carcinoma. One of those articles, carried out by Zembowicz et al., provides histologic evidence for a multistage progression of noninvasive sweat gland neuroendocrine carcinoma to endocrine mucin-producing sweat gland carcinoma and then to mucinous carcinoma of the eyelid. So, both endocrine mucin-producing sweat gland and primary cutaneous mucinous carcinoma are rather distinct stage during the progression of a unique tumor, perhaps the former being precursor of the later.

The last images have changed my opinion from a very low grade predominantly in situ mucinous ( or mucin producing if you prefer ) carcinoma to a low grade invasive mucinous ( or mucin producing ) ca of the eyelids. I completely agree with Robledo ( Zembowicz ).

The important is to rule out a metastasis ( but I think this is primary cutaneous ).

Great case Arti (mucinous carcinoma with solid areas and neuroendocrine differentiation).  I had one on the eyelid a few years ago on frozen sections for suspected nodular BCC. 80% was rather solid and similar to your images 1-4, 20% was more typical mucinous carcinoma (like your later images). I was thinking of hidradenoma in collision with a mucinous carcinoma.  I e-mailed the hot images to Dmitry Kazakov who kindly educated me that the whole lesion was mucinous carcinoma and included a reference on the cases they published of similar cases in AJSP.  I was able to give the correct report to the clinician thanks to him!  I was also catching up and added a little anecdote to the case 1668 (another great case).

The combined brilliance of Robledo and Richard's comments leave me with very little to say!

Yes, this is a case of invasive primary mucinous carcinoma of eyelid showing neuroendocrine differentiation. The patient had no other neoplasia, hence mets were ruled out. This case was initially diagnoses as endocrine mucin producing sweat gland carcinoma, but on MDT review I felt that the areas with abundant pools of mucin and infiltrative growth were more in keeping with an invasive mucinous carcinoma. As Robledo pointed out quite succinctly, the 2 conditions lie on a spectrum with many considering EMPSGC as an immediate precursor to mucinous Ca...the point of distinction being that mucin production is never profuse in EMPSGC nor does it show an infiltrative pattern. I ended up calling it an Invasive mucinous carcinoma with coexistent EMPSGC, but always wondered if the whole lesion was just an invasive mucinous carcinoma with neuroendocrine differentiation. (@Raul, p63 was negative in the whole lesion). Richard's comments are interesting in this regard and I suppose, answer this question. Its great to be educated on one's own case and that is the beauty of this website!!