Bowen disease with matrical differentiation: Report of an exceptional histopathologic presentation

Abstract

Matrical differentiation is the distinctive feature of pilomatricoma and other purely matrical adnexal neoplasms; additionally, foci of matrical differentiation have been also described in hybrid cysts of Gardner syndrome, as well as in a wide variety of benign and malignant cutaneous tumors, including basal cell carcinoma. We report an exceptional case of Bowen disease exhibiting multiple foci of matrical differentiation, as confirmed by means of immunohistochemical studies. Several types of divergent, non‐squamous differentiation have been exceptionally reported in cutaneous squamous cell carcinoma in situ (cSCCIS), including sebaceous, mucinous/glandular, poroid, tricholemmal, and neuroendocrine differentiation; matrical differentiation may be added to this list. Our findings further emphasize the undifferentiated nature of neoplastic cells in cSCCIS.

Giant Pilomatrical Tumor With Broad Epidermal Components: An Example of Histological Diversity and a Potential Diagnostic Pitfall of Tumors With Pilomatrical Differentiation

“…Skin tumors other than pilomatricoma and matrical carcinoma can exhibit matrical differentiation, and BCC or Bowen disease with matrical differentiation 9,10 should also be considered as differential diagnoses because these tumors can contain epidermal components. We did not observe any features suggesting these tumors, however, such as tumor nests with peripheral palisading and mucin deposition in BCC, or dyskeratotic and/or multinucleated cells in Bowen disease.…”

“…Moreover, matrical differentiation can occur in various neoplastic diseases other than pilomatricoma, including noncutaneous tumors. [7][8][9][10][11] Here, we present a case of giant pilomatrical tumor with uncertain malignant potential, exhibiting broad epidermal components, which, to our knowledge, has not been well recognized.…”