Metaplastic spiradenocarcinoma: Report of two cases with sarcomatous differentiation.

Spiradenocarcinoma (SC) is a very rare malignant skin adnexal tumor with sweat gland differentiation that develops from a pre-existing spiradenoma, cylindroma, or hybrid tumor called spiradenocylindroma, or arises de novo. We present two exceptionally rare SC cases showing sarcomatous differentiation; we also discuss the clinicopathologic features of SC, as well as its differential diagnoses and available therapeutic modalities. Given the aggressive behavior of SC, rapid diagnosis and complete removal of the tumor with tumor-free margins is mandatory.

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

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.

Prurigiform Angiomatosis: Reactive Angioproliferation in the Skin and Vascular Endothelial Growth Factors.

Background: Cutaneous benign angioproliferations can be diagnostically challenging and may mimic vascular tumors. Keratinocytes express vascular endothelial growth factors (VEGFs). We studied the angiogenic factor expression pattern in cutaneous lesions with a distinctive pattern of remarkable dermal angiomatosis underlying prurigo-like epidermal changes.

[Seborrheic dermatitis].

Seborrheic dermatitis is a frequent skin disorder in infancy and adulthood. It also often occurs in patients with HIV or neurologic disorders like Parkinson disease or mood disorders. It is characterized by greasy, yellow flakes or scales in areas of high sebaceous gland activity like the scalp, face, chest and upper back.