Locally Advanced Porocarcinoma in a Vietnamese Patient: A Literature Review and Case of a Rare Tumor Diagnosed Using Global Health Collaboration

Abstract

Porocarcinoma is a rare cutaneous adnexal tumor most commonly presenting on the head, neck, or distal lower extremities of elderly patients. Metastasis occurs in up to one-third of cases, with 5-year disease-specific survival plummeting to nearly 30% in advanced cases from greater than 95% in localized tumors. We present a case of porocarcinoma diagnosed utilizing electronic collaboration among an international team of US and Vietnamese physicians. A 57 year-old Vietnamese female with no significant past medical history presented to her physician in Ho Chi Minh City, Vietnam with multiple slow-growing and painless lesions on the tip of her left big toe. Vital signs were within normal limits. Laboratory studies were noncontributory. Several subcentimeter non-tender violaceous papules were observed along the apex of the left great toe, encompassing a portion of the hyponychium and nail bed. Physical examination was negative for regional lymphadenopathy. Punch biopsy of the tumor revealed marked hyperkeratosis and acanthosis. Nests of poroid dermal tumor cells with atypical mitoses and nuclear pleomorphism were observed connecting to the epidermis in a poorly circumscribed, invasive histologic pattern. The patient was diagnosed with subungual porocarcinoma, which was successfully treated with surgical excision. Electronic collaboration platforms allow specialists to participate in remote patient care, thereby decreasing barriers to healthcare access. For this patient with localized porocarcinoma whose prognosis is excellent, electronic collaboration among international providers allowed for timely diagnosis and intervention of this rare disease, thereby positively impacting her outcome.