Acral Angioosteoma Cutis

Abstract

Acral angioosteoma cutis is a rare disease first described in 2006 that is characterized by vascular proliferation with ossification at the acral area, and which bears clinical similarity to pyogenic granuloma. However, there is no lobular pattern in the capillary proliferation that is a typical histopathological feature in pyogenic granuloma. Metaplastic cutaneous ossification is associated with multiple skin diseases and inflammatory conditions such as scars, nevi, basal cell carcinomas, pilomatricomas, chondroid syringomas, and venous stasis. It is rarely associated with vascular proliferation diseases like hemangiomas and pyogenic granulomas. We report a case of capillary proliferation with ectopic bone formation in a 43-year-old female who presented with an ulcerative, dome-shaped subungual nodule on the left fourth toe, which appeared to be a pyogenic granuloma. Because the biopsy findings showed no lobular capillary proliferation, we determined that this case was consistent with acral angioosteoma cutis.

Recurrent acral angioosteoma cutis in a pregnant patient

“…The other theory is that undifferentiated mesenchymal cells undergo metaplastic differentiation in the setting of inflammation or hypoxia. In previous case reports, the investigators believed that the vascular proliferation in both AAOC and PG were induced by vascular endothelial growth factor (VEGF) 2, 3, 4. Endothelial cells produce signals such as bone morphogenic protein (BMP) to induce metaplastic differentiation and ectopic bone formation 9 .…”

“…Since then, there have been only 3 additional cases reported 2, 3, 4. This friable erythematous exophytic papule has clinical resemblance to pyogenic granuloma (PG) but has distinct histologic features.…”

Acral manifestations of soft tissue tumors

“…Since the introduction of the term in 2006 for a series of 11 cases, at least 3 additional cases have been reported under this name. [36][37][38] These lesions occur on any acral site and are often periungual. They clinically and microscopically resemble pyogenic granuloma, with many having ulceration and epidermal collarettes.…”

Acral Angioosteoma Cutis on the Great Toe Mimicking Pyogenic Granuloma

“…first described AAOC as a benign tumor of unknown histogenesis that is distinctive from other cutaneous lesions showing calcification or ossification. Clinically, AAOC can be easily misdiagnosed as one of the benign acral neoplasms 2 3 4 5 . In other similar conditions, the subungual exostosis differs from that in AAOC in that a fibrocartilaginous cap surrounds the lesion without vascular proliferation.…”

“…The pathogenesis of AAOC is still unclear, but we assume that it is similar to that of other hemangiomas showing ossification. According to previous reports, vascular endothelial growth factor (VEGF) and bone morphogenetic protein (BMP) may play an important role in the development of PG with ossification 2 3 4 5 . VEGFs and BMPs are synthesized by various cells including endothelial cells and osteoblasts in response to hypoxia, trauma, or inflammation.…”