Case Number : Case 835 - 29th August Posted By: Guest

Hidradenocarcinoma

vs. Merkel cell carcinoma

malignant nodular hidradenoma????

Hidradenocarcinoma.

Hidradenocarcinoma.

Add Glomangiocarcinoma

it looks poroid to me- most of it looks like a poroid hidradenoma-, but taking into account that the last images show convincing cytologic atypia and some necrosis and that hidradenocarcinomas can look quite bland, I would call this a carcinoma-poroid hidradenocarcinoma. it would be good to see the whole architecture of this lesion though( areas of infiltration etc).

[color=#1C2837][font=arial, verdana, tahoma, sans-serif][size=4]Porocarcinoma[/size][/font][/color]

Porocarcinoma. Poroid cells with areas of clear cytoplasma, ductular formation, atypical cells and some mitoses.

Favor Porocarcinoma (based on these images).[list]
[*]There is edematous vascular stroma, with focal retraction artifact, and ductal differentiation. The cells are medium to large, rounded, eosinophilic to focally glycogenated, with apoptosis and high mitotic activity. Some cells show possible intracytoplasmic lumens. There is subtle peripheral palisading of expansile, bosselated tumor nodules (best seen in first image), with squamous metaplasia.
[*]Hidradenocarcinoma is in the differential (we are not seeing the entire lesion here), but these are rarer; I like seeing a greater clear-cell component.
[*]Immunostains for EMA or CEA (+ in lumens), and BER-EP4 (negative, to r/o a metatypical BCC ) would be useful for confirmation, if H&E is equivocal.
[/list]

I think continuity with surface epidermis, at least focal, is necessary (definitional feature) to the diagnosis of porocarcinoma. I am not able to see any continuity, at least in the images shown, so I favor the diagnosis of hidradenocarcinoma.

I go with porocarcinoma just because non-anaplastic cells are reminiscent of poroid cells. I would expected a hidradenocarcinoma with prominent clefting between the neoplastic lobules and the desmoplastic stroma.

Favor porocarcinoma..

Agreed. I called this porocarcinoma.