I do believe real gyno can have either the hard lump mostly associated with AAS use directly under the nipple, or can be a general, well...mass...of tissue.
I've been doing alot of research with tamoxifen use for treatment of gyno lately. The general consensus around here is that once you get gyno and it becomes fibrous, you have it until surgery. Now, alot of the studies out there deal purely with pubescent gyno in adolescent boys and treatment with tamox; I dont know if this is because the gyno has not become "fibrous" or whether or not long-term gyno can be treated this way. The same studies have been done on old men as well, and have seen similar results, but I do not exactly know much about geriatric gyno, other than that it is due to the lowering ratio of T to E.
Basically, the majority of cases show at least a 50% reduction in size after 2-12 month treatment with tamox (doses range from 10mg/day in one study to 40mg/day in another). In the majority of the studies, there were at least afew non-responders, as well as afew cases that had gyno recurrance at reevaluation after the study had been concluded. One study showed that "lump type" gyno responded better to tamoxifen treatment than "diffuse fatty" type(1). In, I believe, almost all the studies where patients had pain or soreness associated with their gyno, treatment with tamox relieved the symptoms.
Also, these studies show no real problems with longterm use. One study assessed the longterm affects of tamox and the associated cholesterol/lipid values(2). It shows that basically long term use of tamox lowers cholesterol slightly but not significantly.
Four other tamox treatments of gyno studies have been placed into a chart, found within this article(3). Look towards the middle of the page and it will ask whether you want to display the chart in the same window or a new one. It shows the dosage of tamox per day, the duration of treatment, the number of patients and the relative effectiveness. Overall, it seems the higher doses result in a 80% "success" rate, though the qualitative evaluation of "success" is unknown.
1.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14759718
2.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12053091
3.
http://bmj.bmjjournals.com/cgi/content/full/327/7410/301
Personally, I am going to try a 2 month 30mg/day tamoxifen citrate (so 20mg tamox) to see if it will reduce my symptoms of gyno, which I believe are of the "diffuse fatty" type. At the moment I am unable to start my experiment, but I will update eventually when I have concluded it.