Hypersensitivity to Acetylsalicylic Acid or Primary Cutaneous Th2 Cell Lymphoma? Cognitive Autopsy

A 68-year-old male presented with persistent pruritic erythroderma following an acute myocardial infarction, initially suspected to be hypersensitivity to Acetylsalicylic Acid (ASA). Despite the cessation of ASA, the condition persisted, leading to further investigation. Physical examination revealed erythroderma, nail dystrophy, livedo reticularis, and infiltrated hyperchromic lesions. Diagnostic considerations included ASA hypersensitivity, Mycosis Fungoides (MF), and psoriasis. Histopathological examination and immunohistochemical analysis identified perivascular and interstitial lymphocytic infiltrates with CD3, CD4, CD5, CD20, CD45RA, and CD45RO positivity, consistent with MF, a subtype of primary Cutaneous T-Cell Lymphoma (CTCL). The diagnosis was confirmed for primary cutaneous CD4 T-cell lymphoma in the erythrodermic phase, and the patient was treated with Photochemotherapy (PUVA). This case underscores the diagnostic challenges associated with CTCL, often misinterpreted as benign conditions such as drug hypersensitivity. Detailed patient history, physical examination, and comprehensive diagnostic protocols, including immunophenotyping, are essential for accurate diagnosis. The report also highlights the concept of “cognitive autopsy,” reflecting on the cognitive processes leading to a change from an initial misdiagnosis of ASA hypersensitivity to the accurate identification of CTCL. The case exemplifies the importance of integrating clinical judgment with detailed diagnostic workups to avoid diagnostic errors and ensure appropriate patient management.