Papillary adnexal neoplasm (aggressive digital papillary adenocarcinoma) on the ankle of a 15-year-old girl: case report and review of literature from a pediatric perspective

Digital Papillary Adenocarcinoma at the Site of 5 Years of Recurrent Paronychia: Case Report and Literature Review

Digital papillary adenocarcinoma (DPA) is a rare malignant eccrine tumor often misdiagnosed as a benign condition. A 57-year-old Caucasian male with recurrent paronychia and a subcutaneous mass on the distal phalanx of the right fourth digit was diagnosed with DPA after seeking hand surgery evaluation 5 years following onset. A marginal excisional biopsy was positive for Staphylococcus aureus infection and DPA, leading to surgical excision with transmiddle phalangeal amputation for negative margins. DPA, while rare, often presents insidiously, leading to delayed diagnosis and increased risk of metastasis. This tumor has high rates of recurrence and metastasis, most commonly to pulmonary and lymphatic sites. Accurate diagnosis of DPA is challenging due to its resemblance to multiple benign cutaneous conditions. Current treatments focus on surgical excision, with an emphasis on negative margins. Sentinel lymph node biopsy is not routinely performed, although guidelines are difficult to establish due to the rarity of DPA. Diagnosing and treating DPA minimizes metastasis and recurrence. DPA should be considered in patients presenting with recalcitrant or recurring cutaneous lesions. Surgical management remains the primary treatment strategy, with ongoing research needed to optimize treatment protocols and follow-up care.

Clinical, Histopathological and Immunohistochemical Aspects of Digital Papillary Adenocarcinoma: A Case Report and Literature Review

Digital papillary adenocarcinoma (DPA) is a rare malignant eccrine tumor. A 62-year-old female presented with a subcutaneous nodular 1.5cm-mass in the thumb. Macroscopically, a poorly circumscribed mass containing cystic and solid components was observed. Microscopically, epithelial neoplasm consisting of tubular-cystic structures with back-to-back arrangements was observed. The lining epithelium was composed of cuboidal/columnar cells with mild atypia, with micropapillary extensions. Immunohistochemistry revealed double-layered neoplastic epithelium containing two different types of cells: basaloid/myoepithelial and luminal. We recommend two out of vimentin, HMWCK, and D2-40 for myoepithelial/basaloid cells, also CK7 and EMA for luminal/columnar cells. As the tumor had infiltrated the surgical margins, the patient underwent axillary sentinel lymph node (SLN) dissection and re-excision with Mohs micrographic surgery (MMS). Two additional MMS stages were required due to suspicious surgical margin positivity in the frozen sections. The operation was continued despite the risk of loss of function. Upon examination of the permanent sections, we observed no tumors in the suspected positive foci. Additionally, no tumor was found in the surgical margins. No metastasis was detected in the sentinel lymph node. We have reached 300 reported cases of DPA in the literature. We discussed the histopathological and intraoperative diagnostic pitfalls of DPA with a literature review and our experience.

Association of HPV42 with digital papillary adenocarcinoma and the use of in situ hybridization for its distinction from acral hidradenoma and diagnosis at non-acral sites

Digital papillary adenocarcinoma (DPAC) is a rare tumor of sweat gland origin that preferentially affects the digits and has the potential to metastasize. Its tumor diagnosis can be difficult. Well-differentiated variants of DPAC can be confused with a benign sweat gland tumor, in particular nodular hidradenoma. With the recent detection of HPV42 DNA in DPAC by next-generation sequence analysis, we reasoned that this association could be used for diagnostic purposes. To this end, we performed in situ hybridization for HPV42 on 10 tumors diagnosed as DPAC as well as 30 sweat gland tumors of various histology types, including 8 acral hidradenomas. All DPAC were positive for HPV42. Positive hybridization signals for HPV42 were seen in both primary and metastatic DPACs. All other tumors and normal tissues were negative. This study confirms the association of HPV42 with the tumor cells of DPAC through in situ hybridization. The positive test result in all lesions of DPAC and lack of detection of HPV42 in any of the acral hidradenomas or other sweat gland tumors examined in this series is encouraging for the potential diagnostic utility of the assay. As documented by two scrotal tumors of DPAC, the in situ hybridization test for HPV42 can also help support the rare occurrence of this tumor at a non-acral site.

[Digital papillary adenocarcinoma : Four case reports with brief literature review]

Digital papillary adenocarcinoma is a rare but well characterized carcinoma of the sweat glands, which apart from very few exceptions is localized in acral skin. This type of sweat gland carcinoma tends to recur locally and may cause delayed metastases in a few cases. We describe the clinical findings and the broad histopathologic spectrum of four cases of this rare adnexal carcinoma and give a short summary of the literature.