A LyP on the Lip: A Rare Case of Cutaneous T Cell Lymphomatoid Papulosis (LyP) After Kidney Transplant

Introduction: LyP is a rare T-cell lymphoma found in less than 2% of patients annually and even rarer in kidney transplant recipients. Mucosal involvement is uncommon and has been described only in a few case reports. This case describes an unusual presentation of this lymphoproliferative disorder that requires a high index of clinical suspicion. Case Description: A 71-year-old female with a 30-pack-year smoking history and ESKD from diabetic nephropathy underwent a Deceased Donor Kidney Transplant with Thymoglobulin induction. Maintenance immunosuppression included Belatacept, Tacrolimus, Mycophenolate, and Prednisone. 1.5 years post-transplant, she reported a painless non-healing gingival ulcer (image A). Progression of ulceration and negative HSV swab led to a biopsy, which revealed Atypical T/NK cell infiltrate, CD30(+) -consistent with LyP (Image B and D). Viral stains, including EBV, were negative. PET-CT showed focal avidity corresponding to the site of the lesion (Image C). There was no lymph node or sinus involvement. Immunosuppression was modulated to only Belatacept and prednisone. A shared decision was made to continue active surveillance and forego active therapy, given the indolent nature of the disease, and the patient's overall morbidity. At 1 year follow up, the patient and allograft continue to do well with no evidence of disease recurrence. Discussion: LyP is characterized by localized papulonodular lesions and is often indolent. As the disease evolves, systemic manifestations may become clinically apparent. Prompt recognition of LyP and timely adjustment of immunosuppression regimens can help decrease morbidity, limit cytotoxic radiation, and preserve allograft health.(A) Mucosal ulcer (B) Biopsy specimen (H&E) with diffuse pleomorphic lymphoid cells (C) PET-CT of the head and neck with focal avidity pointed by the blue arrows (D) Immunohistochemistry with positive staining for CD2