A rare tumour - metastatic digital papillary adenocarcinoma: literature review, clinical case of successful therapy

Digital papillary adenocarcinoma (DPA) is a rare malignant neoplasm of sweat glands, which was first described by Helwig in 1979 and then classified by Kao in 1987. This disease most often occurs in men aged 50-70 years and is characterized by a relatively favorable prognosis. In most cases, radical excision of the tumor leads to cure. However, 14-47 % of patients develop distant metastases with predominant lung involvement (70 %). The study of etiology and pathogenesis of this rare cancer and its molecular genetic profile seems to be interesting. Currently, there is no clear approach to the treatment of metastatic DPA, but sporadic cases of using chemotherapy have been reported. Aim of the study: to analyze current data on the pathogenesis of DPA, diagnostic features and treatment methods used, as well as to present the first clinical case of treatment of disseminated digital carcinoma with immune checkpoint inhibitors described in scientific literature. Material and Methods. A search of available literature published in Medline, Pubmed, etc. databases from 1984 to 2023 was performed, 21 sources were included in this review. Clinical Case Description. We present a rare case of metastatic digital papillary carcinoma in a 23-year-old male with disease manifestation at the age of 14 years. Lack of vigilance and awareness of oncologists and morphologists did not allow timely diagnosis of malignancy, even in case of 3 local recurrences of the disease. Only biopsy of a metastatic lung nodule with histological and IHC examination (of archival and new material) made it possible to make a correct diagnosis. This case revealed 2 potential targets that could be used for disease control: androgen receptor positive expression and PD-L1 expression with CPS=20. The use of immune response checkpoint inhibitors (ipilimumab + nivolumab) resulted in partial response followed by stable disease.