Home medications were discontinued except for amlodipine, atorvastatin, and entecavir. The patient was treated symptomatically with topical steroids because it was believed that, if the clinical presentation represented DRESS syndrome, it was a mild variant that could be treated topically.4 His case was considered mild because of a lack of confirmed organ dysfunction and a mild protracted course.
After discharge following a 3-day inpatient stay, the patient was followed in the clinic weekly for 3 weeks without considerable change in the skin or laboratory findings. Discontinuation of entecavir was discussed and approved by his hepatologist.
Posthospitalization analysis of the punch biopsy specimen from the chest performed during the patient’s hospital stay revealed a superficial and deep dermal lymphoid infiltrate comprising CD3-, CD5-, and programmed cell death protein 1–positive cells with cytologic atypia in a perivascular distribution. Analysis of the lymph node biopsy specimen performed during the hospitalization showed effacement of the nodal architecture, a polymorphous lymphoid cell population with irregular nuclear contour, and abundant clear cytoplasm associated with high endothelial venules (HEVs). Cells of interest were positive for CD3, CD4, CD2, CD5, and CD7, with a subset staining positive for programmed cell death protein 1, inducible costimulator, CD10, and chemokine (C-X-C motif) ligand (CXCL) 13. CD21 demonstrated an expanded follicular dendritic cell meshwork in association with HEVs. Polymerase chain reaction revealed a clonal T-cell population. These findings of the skin and lymph node biopsies were consistent with AITL. Subsequent bone marrow biopsy with flow cytometry showed a normal CD4:CD8 ratio in T cells and no increase in natural killer cells.
Cyclophosphamide–hydroxydaunorubicin–Oncovin–prednisone (CHOP) chemotherapy was initiated; the patient completed a total of 6 cycles. He has had near resolution of the skin findings and is considered in remission based on a PET scan performed approximately 7 months after the initial presentation.
Comment
Angioimmunoblastic T-cell lymphoma is a rare peripheral T-cell lymphoma, part of a group of aggressive neoplasms that constitute approximately 15% of peripheral T-cell lymphomas and approximately 2% of non-Hodgkin lymphomas in adults worldwide.5 Cutaneous involvement occurs in approximately half of AITL cases and can be the first manifestation of disease.2 Skin findings are largely nonspecific, ranging from simple morbilliform rashes to erythroderma, at times manifesting with purpura.
Given this variability in the presentation of AITL, early diagnosis is challenging in the absence of more specific signs and symptoms.2 It can conceivably be mistaken for common entities such as viral exanthems or drug eruptions, depending on the history and context. DRESS syndrome, a T cell-mediated, delayed type-IV hypersensitivity drug reaction can present in a manner highly similar to that of AITL, with cutaneous involvement (diffuse morbilliform rash, fever, facial edema, and generalized lymphadenopathy) and variable systemic involvement. Laboratory findings of eosinophilia, atypical lymphocytes, and thrombocytopenia also might be seen in both entities.6 Furthermore, the AITL in our patient was accompanied by electrolyte disturbances that were concerning for syndrome of inappropriate antidiuretic hormone secretion, a rare complication of patients with DRESS syndrome complicated by encephalitis.7,8
Our patient met 4 RegiSCAR criteria for DRESS syndrome, warranting high clinical suspicion for an offending drug.9 DRESS syndrome can be caused by numerous medications—most commonly anticonvulsants, sulfonamides, antibiotics, allopurinol, and NSAIDs. A review of our patient’s medication list identified NSAIDs (including salsalate), entecavir, and amoxicillin, as possible culpable medications. Notably, the only new addition to the patient’s regimen was amoxicillin, which did not fit the typical 2- to 8-week timeline for a DRESS syndrome nidus.10 Our patient’s fever began well before the antibiotic was initiated, and skin findings appeared within 1 week after the course of amoxicillin was completed. Although there is documented variability in the latency of onset of DRESS syndrome following administration of a culprit medication,11 it is critical to maintain a broad differential diagnosis to allow for further diagnostic information to be obtained, especially when the medication timeline does not align with the clinical presentation.