Case Number : Case 1193 - 19th January 2015 Posted By: Guest

Clear cell fibrous papule

Yes, clear cell fibrous papule.

Yes, fibrous papule of the nose, clear cell variant.

Clear cell fibrous papule.

Agree. Clear cell fibrous papule.

I'd be thinking that too but would certainly be inclined to run quite a few IHC stains to see what the cells are.

Agree with clear cell fibrous papule.

Well, I did indeed do a bunch of IHC stains. Here is my diagnosis:



[b]-- FIBROUS PAPULE, CLEAR CELL TYPE[/b]
[indent=1][b]COMMENT: [/b]I do not see any evidence to place this lesion into a melanocytic lesion or neural lesion. I think this is a histological variation of fibrous papule. The findings in this lesion closely parallel those described by Lee, et. al in 2005. I do not identify any evidence of malignancy.[/indent]


[center]Reference:[/center]

Lee AN, Stein SL, Cohen LM. Clear cell fibrous papule with NKI/C3 expression: clinical and histologic features in six cases. Am J Dermatopathol. 2005 Aug;27(4):296-300. PubMed PMID: 16121048.

Micro:

This lesion from the right nasal columella is an exophytic papule that contains a population of clear cells in the dermis. These have a slightly frothy quality to the cytoplasm, but many of them are water clear and they merge with a more conventional amphophilic cytoplasm in some of the similar cells. They are not like xanthocytes in that they do not have a uniform foaminess to them. They are also intermixed with a number of venules of varying sizes throughout the field. The surface epidermis contains a small amount of actinic keratosis with evidence of slightly tattered cornified cells, suggesting some degree of rubbing. These clear cells within the dermal component of the lesion are negative with Melan-A, CD34, renal cell carcinoma antigen, Ki67 (clone 30-9), S100 protein, EMA, actin and HMB45. There is some factor XIIIa positivity throughout the field, but not too many of these clear cells pick up factor XIIIa. The smooth muscle actin marker shows that most of the vessels in the lesion are venules. CD63 and CD68 are both positive in the stroma to some degree, but the CD63 has greater positivity.