ABSTRACT
Melanocytic lesions with lichenoid regression may mimic a benign lichenoid keratosis (BLK) histologically. A total of 336 BLKs were reviewed and deeper sections obtained to determine the frequency of this phenomenon. Two cases (0.6%) showed at least 1 melanocytic nest or junctional multinucleated melanocyte (starburst melanocyte) on deeper sections confirmed by MART-1 immunostaining. Both of these cases demonstrated solar elastosis, and 1 case had an effaced rete ridge pattern. Not included in the histological study are 5 additional cases in which the initial slide showed only lichenoid dermatitis, but deeper sections obtained before to the initial sign-out revealed a melanocytic proliferation. These 5 cases would have been signed out as "consistent with BLK" if deeper sections had not been obtained. Fluorescent in situ hybridization (FISH) was performed on 3 cases; in each case, the melanocytes demonstrated a loss of chromosome 9p21 DNA copy number. The finding of nests of genetically altered melanocytes on severely sun-damaged skin strongly suggests that these cases represent lichenoid regression of melanoma in situ. Pathologists should approach a diagnosis of BLK cautiously in the setting of severely sun-damaged skin.
Subject(s)
Carcinoma in Situ/pathology , Lichen Planus/pathology , Melanocytes/pathology , Melanosis/pathology , Skin Neoplasms/pathology , Aged , Antigens, Neoplasm/metabolism , Carcinoma in Situ/genetics , Carcinoma in Situ/metabolism , Chromosomes, Human, Pair 9 , DNA/analysis , Diagnosis, Differential , Gene Dosage , Giant Cells/pathology , Humans , Hyperplasia/pathology , In Situ Hybridization, Fluorescence , Lichen Planus/genetics , Lichen Planus/metabolism , MART-1 Antigen , Melanocytes/metabolism , Melanosis/metabolism , Middle Aged , Neoplasm Proteins/metabolism , Precancerous Conditions/genetics , Precancerous Conditions/metabolism , Precancerous Conditions/pathology , Skin Neoplasms/genetics , Skin Neoplasms/metabolism , Sunlight/adverse effectsABSTRACT
A 52-year-old white man presented with 2 complex cystic masses in his left inguinal region. On histopathologic examination, an asymptomatic nodule between the third and fourth metatarsal heads was diagnosed as an aggressive digital papillary adenocarcinoma (ADPAca), and the complex cysts from the groin represented metastatic disease from the primary acral tumor. The primary tumor was focally positive for immunoreactivity to ferritin antibody, an immunohistologic marker for sweat gland malignancies. Ferritin antibody may prove useful in the diagnosis of aggressive digital papillary adenoma (ADPA) and ADPAca.
Subject(s)
Adenocarcinoma, Papillary/pathology , Sweat Gland Neoplasms/pathology , Toes/pathology , Adenocarcinoma, Papillary/surgery , Diagnosis, Differential , Humans , Male , Middle Aged , Sweat Gland Neoplasms/surgeryABSTRACT
A case of Bowen disease (BD) presenting as longitudinal melanonychia (LM) on the right third fingernail of a 25-year-old African American man is described. Findings from the histopathologic examination revealed full-thickness epidermal atypia, hypergranulosis, and koilocytic changes. Human papillomavirus (HPV) type 56 was identified by polymerase chain reaction. To the best of our knowledge, we describe the first case of BD of the nail unit in which HPV-56 DNA has been identified.