DP24 A case of digital papillary adenocarcinoma linked to human papillomavirus-42

Abstract

Abstract A 60-year-old man with known stage-4 non-small cell lung cancer (NSCLC) and previous right-thumb hidradenoma presented with a 5-month history of a growing vascular lesion on his right great toe. Histology revealed a digital papillary adenocarcinoma (DPA) and positive quantitative polymerase chain reaction (qPCR) for human papilloma virus (HPV)-42 (courtesy of Thomas Wiesner’s research team in Austria). Review of previous histology for the lung and thumb lesions showed histological features consistent with DPA. He re-presented after 2 years with metastatic DPA in his right posterior calf. Following wide local excision (WLE), this locally reoccurred, requiring further excision. Aside from chemotherapy for NSCLC, he was not immunosuppressed and had no history of HPV-related disease. Digital papillary adenocarcinoma is a rare and aggressive neoplasm of sweat glands. Despite being a low-grade tumour, the rates of metastases and reoccurrence are high. Distant metastases are common and can present years after initial presentation. Distant metastases without lymph node spread have been reported. The annual incidence in the USA is ~0.08 cases per 1 000 000, typically presenting in men aged 50–70 years as a solitary lesion on the digits. It can invade muscle, tendons and bone. Owing to its rarity, misdiagnosis and treatment delay are common (Kobayashi T, Hiura A, Oishi K et al. Aggressive digital papillary adenocarcinoma with multiple organ metastases: a case report and review of the literature. Am J Dermatopathol 2016; 38:910–14). Studies show a link between HPV-42 and DPA, with qPCR detecting HPV-42 in known DPA cases (HPV-42 negative in hidradenoma). Human papilloma virus-42 was previously unknown to be oncogenic, and HPV vaccines do not target HPV-42 (Leiendecker L, Neumann T, Jung PS et al. Human papillomavirus 42 drives digital papillary adenocarcinoma and elicits a germ cell-like program conserved in HPV-positive cancers. Cancer Discov 2022; 13:70–84). There are no clear management guidelines and no drug therapy for DPA. Case studies have shown chemotherapy to be ineffective. Management is surgical with either amputation or WLE to avoid reoccurrence or metastases (Leiendecker et al.). Clinical suspicion for DPA should be high given its aggressive nature with regular long-term follow-up to detect reoccurrence or metastases early. More research is required on the epidemiology of this rare tumour in the UK and Europe and on treatment strategy beyond surgical resection, targeting the link between HPV-42 and DPA.