Subcellular expression of CD30 in cutaneous mastocytosis-An important factor for targeted treatment.

Background: The subcellular distribution of CD30 on mast cells and the presence of eosinophils in cutaneous mastocytosis require further investigation, especially as the cell surface expression of CD30 is critical for the therapeutic response of systemic mastocytosis to brentuximab vedotin.

Objective: Investigation of 147 biopsy specimens from 143 patients with cutaneous mastocytosis for mast cell density and distribution, frequency of CD30 expression, CD30 staining patterns, and presence and distribution of eosinophils. Correlation with clinical patterns.

Regressing basal-cell carcinoma masquerading as benign lichenoid keratosis.

Background: Benign lichenoid keratosis (BLK, LPLK) is often misdiagnosed clinically as superficial basal-cell carcinoma (BCC), especially when occurring on the trunk. However, BCCs undergoing regression may be associated with a lichenoid interface dermatitis that may be misinterpreted as BLK in histopathologic sections.

Methods: In order to assess the frequency of remnants of BCC in lesions interpreted as BLK, we performed step sections on 100 lesions from the trunk of male patients that had been diagnosed as BLK.

Contact dermatitis as a systemic disease.

Systemic contact dermatitis (SCD) is a condition occurring in previously sensitized individuals after systemic re-exposure to the same or cross-reacting substance. Systemic route of administration means uptake of an allergen via percutaneous, transmucosal, oral, intravenous, intramuscular, and inhalational routes, as well as through implants. The intimate mechanisms behind SCD are not yet fully understood, but it is thought to be a T-cell mediated delayed type hypersensitivity reaction.