Track
Case ReportsAbstract
Background: ALK-1 positivity in primary cutaneous anaplastic large cell lymphoma (pcALK-1+ALCL) affecting adults is exceedingly rare; thus, the natural course is poorly understood. However, differentiating it from systemic ALCL is imperative as it is more aggressive, presenting with B symptoms, generalized lymphadenopathy, and extranodal disease. Objective: Our report showcases a patient with over two decades of pcALK-1+ALCL, which was non-treated or only surgically excised for a long period, with eventual extracutaneous spread prompting systemic chemotherapy. Methods: Retrospective review of the clinical and immunohistochemical data from a patient with over 20 years of follow-up. Presentation: A 57-year-old patient with pcALCL (diagnosed 15 years prior) presented in 2012 with slow-growing nodules on the right proximal upper arm. The patient was treated with local excision. Histology revealed CD3+, CD4+, CD45+, CD30+, EMA+, and cytoplasmic ALK-1 expression of large pleomorphic cells. No systemic symptoms or lymphadenopathy were detected during the years of surveillance. In 2015, the patient was hospitalized for excruciating abdominal pain. A bulky peri-gastric mass revealed the same histology as their cutaneous lesions. Notably, no lymph node involvement was found. The patient underwent CHOP chemotherapy and has remained disease-free since treatment. Conclusion: This case highlights a unique presentation of pcALCL with variant (cytoplasmic) ALK-1 expression and is the first report that follows the natural history of the disease. It also reveals that pcALK-1+ALCL can remain indolent for decades before developing systemic dissemination without nodal spread. Accordingly, pcALK+ALCL requires lifelong monitoring and has dermatologic and oncologic implications.