Case Number : Case 547 - 13 July Posted By: Guest

Focal mucinosis

[b]Digital Mucous/myxoid cyst.[/b]

[b]Digital myxoma (a.k.a. digital mucus cyst).[/b]

[b]I would like to add myxoid neurofibroma and myxoid neurothekoma in the DD (S100 and EMA would help).[/b]

[size=4][font=courier new,courier,monospace][color=#231F20][color=#231F20]Myxomatous change. Considering the clinical data too, I would suggest [/color][color=#000000][b]superficial acral fibromyxoma[/b] or [/color][color=#231F20][b]m[b]yxoid [/b]cyst,[/b] possibly [b]traumatic[/b] in this site. [/color][/color][/font][/size]

Digital mucous cyst

Digital mixoid cyst

To me, its a bit too cellular to be a simple myxoid cyst. The spindle and stellate cells made me favour a superficial acral fibromyxoma.

However in the images on the bottom (esp the bottom right), there are a few cells which do look pleomorphic and atypical. Thus I do wonder about acral myxoinflammatory fibroblastic sarcoma. But atypical cells have been described in Superficial acral angiomyxoma and I am not really sure how to make the distinction.

[size=4][font=courier new,courier,monospace]Well, my[color=#231F20]xoinflammatory fibroblastic sarcoma (many cases are clinically diagnosed as ganglion cysts), shows [/color][color=#000000][b]numerous inflammatory cells[/b] in addition to the [/color][color=#231F20][b]neoplastic[/b] [b]cells[/b]. [b]Immunohistochemistry[/b] is useful too. [/color][/font][/size]

Well this in fact came with the additional history that he was tree surgeon
and the area was being repeatedly traumatised during his work. Consequently
our diagnosis was a mucus cyst (traumatic type). I have seen very few
examples of traumatic type mucus cyst as by far the more common type of
digital mucus cyst we see is the ganglionic type usually presenting overlying a distal
interphalyngeal joint. In the latter you more often than not can see a
deeper component lined by synoviocytes. I agree without the context one could
consider the differential diagnoses of superficial acral fibromyxoma and
angiomyxoma. You probably already know I think soft tissue pathology is a dark
art!