Acrokeratosis paraneoplastica, also known as Bazex syndrome, is a relatively understudied yet clinically important dermatological condition that is inextricably associated with squamous cell carcinoma, predominantly of the upper respiratory and gastrointestinal tracts. Manifesting as unique psoriasis-like cutaneous lesions, Bazex syndrome functions as an early warning signal for underlying malignancies, underscoring the urgent need for its timely diagnosis and intervention. Notwithstanding its clinical relevance, the molecular and cellular mechanisms underpinning its pathogenesis are not fully understood. To address these gaps, this comprehensive literature review undertook a meticulous search across reputable databases such as EMBASE, MEDLINE/PubMed, and Web of Science. Our analysis ventures into multiple putative pathogenic pathways, including shifts in Th2 immune responses, aberrant secretion of growth factors, and immunological reactions to tumor-specific antigens. We also detail the clinical phenotypes of Bazex syndrome and their chronological linkage with the corresponding malignancies. Finally, the review evaluates the therapeutic effectiveness of various approaches, including but not limited to targeted cancer treatments, PUVA therapy, and topical corticosteroids. This synthesis aims to arm healthcare providers with a nuanced understanding of Bazex syndrome, facilitating more accurate diagnosis and tailored treatment paradigms.

Acrokeratosis paraneoplastica (Bazex syndrome) is a rare paraneoplastic dermatosis associated with internal malignancies. Clinical presentation is characterized by erythematous or violaceous scaly plaques involving the digits, nose, ears, palms, and soles. Nail changes commonly present concurrently with cutaneous manifestations. In this review, we characterize nail changes associated with acrokeratosis paraneoplastica. A total of 48 cases were analyzed. Nail findings were nonspecific, with the most common being nail plate thickening, onycholysis, subungual hyperkeratosis, longitudinal ridging, discoloration, and nail plate loss. In most patients, nail changes involved the majority of fingernails and toenails and most often appeared prior to the diagnosis of malignancy. The most common associated underlying malignancies were squamous cell carcinomas of the head and neck. A diagnosis of acrokeratosis paraneoplastica should be considered in patients with onychodystrophy involving multiple nails with accompanying atypical psoriasiform dermatoses. Screening for internal malignancies may significantly decrease morbidity and mortality for these patients.

Acrokeratosis paraneoplastic (Bazex syndrome) is a rare, but distinctive paraneoplastic dermatosis characterized by erythematosquamous lesions located at the acral sites and is most commonly associated with carcinomas of the upper aerodigestive tract. We report a 58-year-old female with a history of a pigmented rash on her extremities, thick keratotic plaques on her hands, and brittle nails. Chest imaging revealed a right upper lobe mass that was proven to be small cell lung carcinoma. While Bazex syndrome has been described in the dermatology literature, it is also important for the radiologist to be aware of this entity and its common presentations.