Adenodermatofibroma possessing dilated glandular structures with eccrine features: A case study

Abstract

Adenodermatofibroma is a newly recognized variant of dermatofibroma characterized by dense proliferation of fibroblasts and histiocytes admixed with dilated glandular structures showing apocrine secretion. Only five cases of adenodermatofibroma have been reported to date. We report an additional case of adenodermatofibroma on the back of a 67-year-old female. In addition to the dilated glandular structures, nondilated eccrine units were present at the upper periphery of the lesion, above which the normal eccrine glands reside. Although decapitation secretion was observed in the nondilated eccrine units at the upper periphery of the lesion, this was not observed in the dilated glandular structures. The inner cells of the dilated glandular structures were S-100 positive, similar to those of the secretory portion of eccrine glands. We considered the glandular structures in our patient were derived from the entrapped eccrine units. We suggest that the term "apocrine metaplasia" be applied to eccrine units showing decapitation secretion.

Two cases of adenodermatofibroma

“…The cases reviewed, along with our lesions, were present in the dermis or subcutis, and were composed of a dense proliferation of fibroblasts and histiocytes admixed with dilated glandular structures. Most of the lesions also had a prominent vascular component, with occasional telangiectasias and hemosiderotic changes 4 . Patient 1's specimen contained irregular hemorrhagic cleft‐like spaces without an endothelial lining, similar to previously described adenodermatofibromas with hemosiderotic stroma 1,3,4 …”

“…In our opinion, the more likely pathogenesis is a theory suggested by both Gonzalez and Santos‐Briz et al, proposing that the glands are a result of a glandular induction phenomenon similar to the basaloid induction phenomenon seen in typical DFs 2,6 . Just as dermatofibromas can induce changes in the epidermis, follicle, and sebaceus glands, the dermatofibroma could have induced the formation of apocrine structures 2‐4,6‐8 . Recently, Muto et al has expanded this theory to specifically suggest that the dilated glands are the result of entrapped eccrine glands that undergo apocrine metaplasia 4 .…”

“…An apocrine gland cyst with hemosiderotic dermatofibroma‐like stroma was first described by Gonzalez et al in 2005 3 . Since that first report, only five other cases have been reported 2‐5 . The term “adenodermatofibroma” to describe dermatofibromas with a glandular component was first proposed by Santos‐Briz et al, which has largely been accepted in the literature 2,4,6 …”

“…Muto et al summarized the features of adenodermatofibromas 4 . Interestingly, adenodermatofibromas are not preferentially found in regions that are normally abundant with apocrine glands, suggesting that at least in some cases either the glands are not apocrine in origin, or have undergone apocrine metaplasia.…”

“…An adenodermatofibroma is a variant of DF first coined by Santos‐Briz 2 and first described by Gonzalez in 2005 3 . It is characterized by the proliferation of fibroblasts and histiocytes of a dermatofibroma, admixed with a varying density of entrapped dilated glandular structures 2,4 . So far, only six cases of adenodermatofibroma have been reported 2‐5 .…”