Pseudocarcinomatous Hyperplasia Hiding Lymphomatoid Papulosis: A "Low-Power View" Pitfall.

Pseudocarcinomatous hyperplasia (PCH) is a reactive proliferation of the epidermis that can be associated with many inflammatory and neoplastic conditions. Histologically, it is characterized by irregular strands of epidermis, usually at the level of the follicular infundibulum, projecting downward into the dermis. The differentiation between a well-differentiated squamous cell carcinoma and PCH can be particularly challenging when the biopsy is superficial and the causing lesion is dermal-based. Lymphomatoid papulosis (LyP) is an uncommon, self-healing, recurrent, cutaneous T-cell lymphoma, included among the primary cutaneous CD30-positive T-cell lymphoproliferative disorders. LyP is characterized by a chronic course of years to decades that does not compromise survival, even if patients with LyP are at risk for second cutaneous or nodal lymphoid malignancies. LyP and other lymphomas are major neoplastic causes of PCH and can be misdiagnosed or completely overlooked if the PCH is particularly exuberant. We describe the case of an otherwise healthy 55-year-old man who presented with a 3-month history of erythematous papules on upper and lower limbs. A diagnosis of LyP associated with PCH was made after 3 skin biopsies. The propensity of the CD30+ cutaneous lymphoproliferative disorders to an incognito growth pattern is well recognized, and a low-magnification scanning of the histological slides can be an inappropriate approach.

Update on non-melanoma skin cancer and the value of dermoscopy in its diagnosis and treatment monitoring.

Dermoscopy has become an integrative part of the clinical examination of skin tumors. This is because it significantly improves the early diagnosis of melanoma and non-melanoma skin cancer (NMSC) including basal cell carcinoma and keratinocyte skin cancer compared with the unaided eye. Besides its value in the noninvasive diagnosis of skin cancer, dermoscopy has also gained increased interest in the management of NMSC. Dermoscopy has been used in the preoperative evaluation of tumor margins, monitoring of the outcomes of topical treatments and post-treatment follow-up. This article provides an update on NMSC with special emphasis on dermoscopy in the diagnosis and management of basal cell carcinoma, actinic keratosis, Bowens' disease and squamous cell carcinoma.