Case Number : Case 851 - 20th September Posted By: Guest

Cutaneous carcinosarcoma

BCC

D.D:BCC vs Trichoblasroma ( basaloid variant)

The strong anf diffuse positivity of BerEP4 is typical of BCC and not basalod trichoblastoma in which it is focal and weak

Althogh a papillary mesenchymal body is seen, the seperation artifact is between the tumor and the fibromyxoid stroma which is a feature typical of BCC and not Trichoblastoma

BCC with sarcomatous differentiation is a good catch from Engin

Cutaneous carcinosarcoma with carcinoma component represented by basal cell carcinoma.

Carcinosarcoma, epithelial component is BCC

Agree, a rare case of cutaneous carcinossarcoma with the epithelial component composed of BCC.

Cutaneous carcinosarcoma.

would probably do some more immunos to see if the spindle cell component stains with anything specific.
But otherwise agree with carcinosarcoma.

Just to make something different, I gonna use a synonym: metaplastic basal cell carcinoma. The sarcomatoid component is probably originated from the epithelial one.

[size=4][font=arial,helvetica,sans-serif]This looks like a superficial and nodular BCC.

Although there is aberrant mitoses in the surrounding stroma, this stroma appears to be well circumscribed and completely/concentrically distributed around basaloid tumor nodules, with absence of asymmetric infiltration/extension into the surrounding dermis, and absence of chronic host inflammatory reaction. This is a low-power histology pattern I would [i]not [/i]expect of a sarcomatous/spindle cell degeneration of a epidermal carcinoma.

Nevertheless, it pays to be cautious. Any case with this kind of atypical spindled stroma deserves an additional stain for high molecular weight cytokeratin such as CK5, and/or 34betaE12 (covers HMW cytokeratins 1,5,10, and 14), or P63 to help exclude the worst-case scenario of a spindle-cell/poorly differentiated carcinoma. [/font][/size][font=arial, helvetica, sans-serif][size=4]Some spindle cell carcinomas will be negative for these markers, notwithstanding. [/size][/font][font=arial, helvetica, sans-serif][size=4] ( Pancytokeratin AE1/AE3 is very unreliable and insensitive as a carcinoma marker in this scenario ). [/size][/font]

[size=4][font=arial,helvetica,sans-serif]An EMA stain would be useful to exclude a sneaky Merkel cell carcinoma masquerading as BCC or SCC, as MCC is usually simultaneously positive for EMA and BerEP4, unlike BCC (BerEP4 positive only) or SCC (EMA positive only). [/font][/size]

Agree, BCC with malignant sarcomatoid component. Prognosis should be good.

I reported this case as follows: Nodular basal cell carcinoma with tight peritumoural sarcomatoid
element, the latter of doubtful clinical significance. Depth 1.8mm (it was a superficial shave biopsy)

I recorded the IHC (for academic interest) in my slide collection database (See Mark's blogs on filing references) as follows:
Epithelium diffuse BerEP4, Pank, 34BE12, p63, Ki67 50%; p53++80%; EMA neg
Stroma: Neg for BerEP4, Pank, 34BE12, p63 & EMA; Ki67 10%; p53+20%.

Interestingly we reported a cutaneous sarcoma NOS on his scalp last year (fully excised) and he has had multiple H&N NMSC's. I suppose there is a differential diagnosis of a recurrence / cutaneous metastasis of the previous cutaneous sarcoma NOS and collision with BCC.

has this patient ever received scalp radiotherapy?

[quote name='Dr. Richard Carr' timestamp='1379739766']
I reported this case as follows: Nodular basal cell carcinoma with tight peritumoural sarcomatoid
element, the latter of doubtful clinical significance. Depth 1.8mm (it was a superficial shave biopsy)

I recorded the IHC (for academic interest) in my slide collection database (See Mark's blogs on filing references) as follows:
Epithelium diffuse BerEP4, Pank, 34BE12, p63, Ki67 50%; p53++80%; EMA neg
Stroma: Neg for BerEP4, Pank, 34BE12, p63 & EMA; Ki67 10%; p53+20%.

Interestingly we reported a cutaneous sarcoma NOS on his scalp last year (fully excised) and he has had multiple H&N NMSC's. I suppose there is a differential diagnosis of a recurrence / cutaneous metastasis of the previous cutaneous sarcoma NOS and collision with BCC.
[/quote]

A great case! It would be interesting to compare the atypical stroma of this tumor to the previous one, and possibly to other tumors, to see if there is similarity. That may shed light on the significance of the cytologic features in differentiating sarcoma from a pseudosarcomatous stroma (which I favor more strongly than before, in light of the helpful negative IHC stains).