Case Number : Case 847 - 16th September Posted By: Guest

Clonal (nested) Bowen's disease

[size=4][font=Palatino Linotype, serif][color=#000000]Bowen disease with Borst-Jadassohn phenomenon.[/color][/font][/size]

[color=#000000][font=arial, helvetica, clean, sans-serif][size=3]The pattern here is for intraepidermal epithelioma of Borst-Jadassohn phenomenon (BJP). Tumors showing the BJP are mainly clonal seborrheic keratoses and clonal Bowen disease .However intraepidermal sebaceus ca ,inraepidermal porocarcinoma and intraepidermal merckel cell ca may also show BJP.[/size][/font][/color][color=#000000][font=arial, helvetica, clean, sans-serif][size=3]In this case the cells in the nests are vaculated so I may go for intraepidermal sebaceus ca [b].[/b][/size][/font][/color]

[size=3][font=arial,helvetica,sans-serif]"Clonal" seborrheic keratosis with Borst-Jadassohn effect.[/font]

[font=arial,helvetica,sans-serif]Agree with Maria's excellent differential. I see the nuclear and cytoplasmic vacuolation to be artefactual, given the similar effect in the background epidermis; this artefact makes it more difficult to assess cytology. There is some apoptosis, but absence of multinucleation, significant nuclear pleomorphism, or mitotic activity that is any different than the surrounding epidermis. The nests are scattered evenly with minimal parakeratosis, in a background of broadly reticulated acanthosis. [/font][/size]

Before the IHC I was agreeing with Jim i.e. Seborrhoeic keratosis. The only one of these markers I use is Ki67 and I find it usually unhelpful - does look rather high here!

I find p53 (diffuse strong or null in Bowen's/IEC) helpful in some cases and p16 helpful in some more cases (diffuse in clonal bowen's/IEC).

Odd site for a clonal lesion as most in my experience occur on the lower leg for some reason.

Pagetoid variant of Bowen disease.

[b]In seborrhoeic keratosis there is poor correlation between the clinical appearance and histopathology[/b] (sometimes the descriptive term [i]benign squamous keratosis[/i] is used). Having said so, clinical description will be very helpful in this regard as the differential diagnosis usually poses no problems. Some used the term intraepidermal epithelioma of Borst and Jadassohn, but most now do not and describe presence of sharply defined nests of morphologically different cells within the epidermis as [b]Borst–Jadassohn phenomenon (not epithelioma)[/b]. Lesions showing the phenomenon include [b]benign and malignant entities[/b]. Examples include clonal seborrhoeic keratosis, Bowen’s disease, intraepidermal poroma, and intraepidermal malignant poroma. There is widespread expression of CK10 in almost all cases of Bowen’s disease.