Case Number : Case 2562 - 01 May 2020 Posted By: Dr. Richard Carr

Cutaneous epithelioid angiomatous nodule

I was making the same diagnosis. 
So agree with Mona.  
There is only an important differential here: Bacillary Angiomatosis. But I don’t see any purplish grey bacterial colonies, and BA is a very rare condition nowadays. 
 

30 minutes ago, Dr. Mona Abdel-Halim said:

Cutaneous epithelioid angiomatous nodule

Agree

looks like capillary angioma

Thank you for the contibutions. The proliferaiton in cutaneous epithelioid angiomatous nodule should be as follows: "Histologically, the lesions were located superficially in dermis (or submucosa) and consisted of a circumscribed, unilobular, mainly solid proliferation of large polygonal epithelioid endothelial cells with vesicular nuclei and conspicuous nucleoli."

I think the lesion illustrated here has a dual population of endothelial (CD31 / CD34) and pericytes / smooth muscle cells (SMA) so I guess this lesion is just a rather solid appearing lobular capillary haemangioma (pyogenic granuloma). I've only diagnosed CEAN once and unfortunately the referring pathologist had already cut the lesion through with levels so it was not possilble to do smooth muscle actin. It's benign so I guess this is somewhat academic.

8 hours ago, Dr. Richard Carr said:

Thank you for the contibutions. The proliferaiton in cutaneous epithelioid angiomatous nodule should be as follows: "Histologically, the lesions were located superficially in dermis (or submucosa) and consisted of a circumscribed, unilobular, mainly solid proliferation of large polygonal epithelioid endothelial cells with vesicular nuclei and conspicuous nucleoli."

I think the lesion illustrated here has a dual population of endothelial (CD31 / CD34) and pericytes / smooth muscle cells (SMA) so I guess this lesion is just a rather solid appearing lobular capillary haemangioma (pyogenic granuloma). I've only diagnosed CEAN once and unfortunately the referring pathologist had already cut the lesion through with levels so it was not possilble to do smooth muscle actin. It's benign so I guess this is somewhat academic.

Thanks Dr. Carr for this explanation. I was also thinking of pyogenic granuloma in this case. I have seen an occasional case of PG exhibiting epithelioid appearing endothelial cells, but overall silhouette and features are of PG. While working on these cases, I came across an old publication which mentions "the occasional epithelioid appearance of the lining endothelial cells may cause confusion with epithelioid hemangioma" as one of the pitfalls in diagnosis of PG.

Kapadia SB, Heffner DK. Pitfalls in the histopathologic diagnosis of pyogenic granuloma. Eur Arch Otorhinolaryngol. 1992;249(4):195‐200.

Thanks very much. Certainly I believe you can see quite plump endothelial (and pericytic cells) in a variety of benign lesions including PG. Often this is not in the publications or textbook. Curiously the original papers on CEAN don't discuss the differential of the the humble PG!

Thanks Richard. Nice learning point!

On 01/05/2020 at 12:42, Dr. Mona Abdel-Halim said:

Cutaneous epithelioid angiomatous nodule

I agree, nice case.