The limited value of sentinel lymph node biopsy in lentigo maligna melanoma: A nomogram based on the results of 29 years of the nationwide dutch pathology registry (PALGA).

Background: Lentigo maligna melanoma (LMM) predominantly presents in the head and neck of the elderly. The value of sentinel lymph node biopsy (SLNB) for LMM patients remains to be determined, as the reported average yield of positive lymph nodes is less than 10%. In this nationwide cohort study, we wanted to identify LMM patients with an increased risk of SLNB-positivity.

Hedgehog pathway mutations are involved in the pathogenesis of plaque-type "trichoblastoma": A report of two cases.

We present two cases of plaque-type trichoblastoma with atypical foci. A rare variant of trichoblastoma is the plaque variant, which is characterized by poor circumscription and locally infiltrative growth pattern. These lesions mostly require multiple stages of Mohs micrographic surgery.

A Low-Grade Trichoblastic Carcinoma Treated with Mohs Micrographic Surgery.

Trichoblastomas are rare dermal neoplasms usually found on the scalp and face. Histology shows a proliferation of small basaloid cells arranged in cords or fields surrounded by cellular stroma. Trichoblastomas are usually not aggressive, but trichoblastic carcinomas arising from preexisting trichoblastomas have been described and have been linked to basal cell carcinoma.

Histopathology of Red Tattoo Reactions.

Background: Despite popularity of tattoos, complications may occur. In particular, red tattoo reactions due to allergic reactions are the most frequent chronic tattoo reactions. However, little is known about its histopathology and underlying pathomechanisms.