Solitary cutaneous mastocytoma

[Itchy02]

Greetings -  I'm 43 years old, and developed a small (about 1/4 diameter) itchy lump on my upper chest, roughly two years ago.  When it did not resolve, I sought treatment.  I was initially given Triamcinilone cream, which I used for about 6 months, to no great avail.  Subsequently, a biopsy showed signs of "mast cell disease", which my dermatologist later charaterized as a solitary cutaneous mastocytoma.  He injected more triamcinilone subcutaneously, which reduced the itching and flushing to a large extent, but only for a few weeks before all had returned to its former state.  That was about 10 weeks ago, and if anything, this seems to be slowly growing larger, effecting a greater area.  The "density" has remained roughly the same size, but the flushing is increasing and becoming more rash-like, and the skin around the lump is becoming scaly and such.

I have read some literature on the general topic of mastocytosis and mastocytomas, but it is pretty slim for the latter, presumably due to the rarity of adult-onset cases and apparent self-resolution in many children.  However, there are frequent allusions to the possiblity that adult-onset mastocytomas can continue development to a point of involvement of internal organs, which seems a non-trivial concern in light of the fact that systemic mastocytoma appears to have no real treatment.

My dermatologists admits that he has only seen a few cases of adult mastocytoma his entire career, and his assessment was simply that I "may need to get a steroid injection every year" ... presumably for the rest of my life.  But we've been attacking this with steroids for a year, to no avail.  Alternatively, I have seen in the medical literature reference to successful treatment via surgical excision (see Ashinof et al. 1993, J. Derm. Surgery and Oncology, v19).

And so, my questions are as follows:  a) should I be concerned that a presumably benign cutaneous mastocytoma could become more than just that, and b) why would we not excise the thing now, and potentially be done with it, rather than continue treatment with potentially ineffective topical steroids?  (Or an alternative on (b) might be: for how long is reasonable to attack this with steroids in hopes they'll work, before taking the scalpel to it?)

Thanks in advance for your insights ... or if this is an oddball that's outside of your experience, for any cross-referencing that you might be able to provide me with.