Case Number : Case 1871 - 31 July - Dr Limin Yu Posted By: Guest

probable AFX for excision and complete evaluation. IHC should be performed also to discard the differentials

given the location, AFX will be lower on my list of differentials for a malignant spindle cell neoplasm but agree, IHC needed to assess the usual suspects. favour fibro/fibrohistiocytic on morphology.

urmilapandey:"given the location, AFX will be lower on my list of differentials for a malignant spindle cell neoplasm but agree, IHC needed to assess the usual suspects. favour fibro/fibrohistiocytic on morphology."

Agree, and my first spot is Epithelioid Cell Histiocytoma. Unusual epidermal ulceration, but it has been described in this dermatofibroma variant.

42 minutes ago, vincenzo polizzi said:

urmilapandey:"given the location, AFX will be lower on my list of differentials for a malignant spindle cell neoplasm but agree, IHC needed to assess the usual suspects. favour fibro/fibrohistiocytic on morphology."

Agree, and my first spot is Epithelioid Cell Histiocytoma. Unusual epidermal ulceration, but it has been described in this dermatofibroma variant.

 

haven't seen many. so not much experience. can epithelioid histiocytoma show diffuse atypia with mitoses..?

In "Cutaneous Soft Tissue Tumors" of Requena/Kutzner, pg 21, epithelioid cell dermatofibroma is reported with (sometimes) scattered mitosis and, in general, with the architecture and cytology of a Spitz Nevus...

33 minutes ago, vincenzo polizzi said:

In "Cutaneous Soft Tissue Tumors" of Requena/Kutzner, pg 21, epithelioid cell dermatofibroma is reported with (sometimes) scattered mitosis and, in general, with the architecture and cytology of a Spitz Nevus...

thanks for that information Vincenzo

Agree, cellular DF most likely. These tumours can be quite mitotically active and atypia is well described as well (including 'monster cell' variants).

Ulceration is unusual...so would do the usual panel of immunos to exclude other differentials. 

Yes, cellular fibrous histiocytoma

I got some alarming features, including ulceration, increased cellularity, and brisk mitotic activity, but the incomplete excision does not allow microscopic analysis of the whole lesion. Considering the site and the not-so-elderly patient, this tumor has low cellular pleomorphism and fascicular growth pattern with admixed lymphocytes, so I tend to favor a more common benign cutaneous mesenchymal tumor like some variant of fibrous histiocytoma.

Cellular DF. Ulceration unusual indeed.

This is a cellular fibrohistiocytoma. I have learned a lot for your discussion. Thank you!