Perianal Paget disease (PPD), an uncommon extramammary Paget disease, is characterized by intraepidermal pagetoid spread of atypical Paget cells in the perianal skin. PPDs can be primary or secondary. We report the clinicopathological features of 8 cases of PPD in Taiwanese and first describe differential CK7 expression in the epidermal and dermal tumor cells in 2 cases of secondary PPDs, which may provide a clue to the diagnosis of secondary PPD. Since an underlying anorectal carcinoma in PPDs may be undetectable by colonoscopy, it is essential to consider anoscopy and/or anal canal mucosal biopsy to search for an occult anorectal carcinoma.
Expression of programmed death-ligand 1 and programmed death-1 in patients with extramammary paget's disease
Extramammary Paget's disease (EMPD) is a rare skin cancer and sometimes has fatal prognosis. For progressive cases, therapeutic options are limited. In recent years, treatment with an anti-programmed death-1 (PD-1) antibody has improved the prognosis of various malignancies. In addition, correlations between PD-ligand 1 (PD-L1) expression in tumor cells and favorable responses to anti-PD-1 therapy have been reported for several cancers. There have been a few case series of analysis of PD-L1 expression in patients with EMPD. The purpose of this study was to investigate the relationship between the EMPD and PD-L1/PD-1 expression in Japanese EMPD patients. We investigated 39 patients with EMPD by immunohistochemical staining of PD-L1 and PD-1. We counted the number of tumor cells that were positive for PD-L1 and the number of tumor-infiltrating mononuclear cells (TIMCs) that were positive for PD-L1 and PD-1. We also analyzed correlations between the expression of PD-L1 and PD-1 in EMPD and patients' characteristics. We found that none of the Paget's cells expressed PD-L1. All of the specimens contained TIMCs, and some of the TIMCs expressed PD-L1 and PD-1. However, there was no correlation between the expression of PD-L1/PD-1 in TIMCs and patients' characteristics. Although tumor cells did not express PD-L1 and the expression of PD-L1/PD-1 in TIMCs did not correlate with patients' characteristics, future clinical studies should be carried out to explore another immune escape pathway in EMPD.