Intradermal Band-like Lipomatous Metaplasia Can Be Associated With the Regression of Overlying Skin Neoplasms: A Clinicopathologic Study of 20 Cases

Abstract

Lipomatous metaplasia has been rarely reported in both neoplastic and inflammatory dermatological disorders. Most neoplastic cases show the lipomatous change within the tumor silhouette, but band-like lipomatous metaplasia in the dermis under tumors has not been well-described. The aim of this study was to reveal the characteristics and relationship of intradermal band-like lipomatous metaplasia and coexisting skin tumors. A total of 20 cases with intradermal band-like lipomatous metaplasia were retrieved from 10,992 archive cases between April 1997 and March 2020 at Hyogo Cancer Center, and subjected to a detailed clinicopathologic analysis. Nine (45%) patients had superficial variant basal cell carcinoma as a coexisting neoplasm. Eight (40%) patients had squamous cell carcinoma, 5 of which were in situ. The remaining 3 (15%) cases were invasive extramammary Paget disease. All 20 cases showed at least one of 3 signs of tumor regression, namely, partial loss of overlying neoplasia, significant inflammatory infiltrate under the tumor, and fibrosis around the tumor. We concluded that intradermal band-like lipomatous metaplasia could be seen in association with the regressing process of cutaneous superficially-spreading neoplasms.

A case of cutaneous syncytial myoepithelioma with extensive adipocytic metaplasia: Usefulness of EWSR1‐PBX3 gene fusion analysis

“…Although myoepithelial neoplasms arising in the parotid glands and submandibular glands also exhibit extensive adipocytic metaplasia, 11,12 most cases of CSM present adipocytic metaplasia only focally 4,5,9 . The mechanism underlying the frequent occurrence of adipocytic metaplasia in CSM is still unclear; however, a similar pattern of adipocytic metaplasia has been reported in patients with several inflammatory skin diseases and the regression of malignant skin tumors 13,14 . In our case, a large number of inflammatory cells infiltrated around the tumor, which might have caused adipocytic metaplasia.…”

“…The patient had a solitary 7-mm red-colored and dome-shaped papule on her thigh several inflammatory skin diseases and the regression of malignant skin tumors. 13,14 In our case, a large number of inflammatory cells infiltrated around the tumor, which might have caused adipocytic metaplasia. Previous cases of CSM with adipocytic metaplasia also showed inflammatory cell infiltration around the tumor.…”