Primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder: 20 years of experience from a specialist...

Primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder (PCSM-TLPD) is a rare subtype of indolent lymphoproliferative disease. The treatment, investigations and follow-up protocol are being re-evaluated.

To use our service evaluation to understand the presentation, response rate, relapse rate, treatment variation, progression-free (PFS) and overall survival (OS) of our cohort.

We identified 86 patients with PCSM-TLPD from our skin tumour unit database who were diagnosed by the specialist multidisciplinary team at our centre between 2005 and 2024. As well as demographics and clinical features, OS, PFS, response to treatment and risk factors for relapse were investigated.

Eighty-six patients [mean (SD) age 54.9 (14.1) years; median 56 years (range 17-87)] were included. The majority of PCSM-TLPD lesions presented as solitary nodules (n = 75) on the head and neck (n = 51). Eighty-one patients underwent imaging (positron emission tomography, n = 44; computed tomography of the thorax, abdomen and pelvis, n = 37), with no evidence of nodal or systemic involvement in 100% of cases. Forty-seven patients had a diagnostic biopsy that resulted in spontaneous resolution for 16 patients. Thirty-one patients had a residual lesion and were treated with topical steroids (n = 20) or radiotherapy (n = 11). Thirty-nine patients had a complete excision, followed by monitoring alone for 33 patients. Six had radiotherapy after excision. All patients achieved complete remission. Patients initially presenting with multiple lesions (n = 11) were more likely to relapse [7 of 11 with multiple (64%) vs. 3 of 75 (4%) with solitary lesions] (P < 0.001). Three patients died from unrelated illnesses during follow-up. The median duration of follow-up was 3.1 years (interquartile range 1.2-4.9). The median PFS was not reached due to insufficient events. The overall relapse rate was 12% following initial monitoring or treatment. To date, disease-specific survival is 100%.

PCSM-TLPD carries an excellent prognosis, especially for those presenting with a solitary lesion. There was no disease-related death in our patients up to 20 years after presentation. Staging scans confirm no systemic disease and may no longer be required for these patients. Patients can be monitored or treated with low dose radiotherapy (8 Gy in two fractions) if they do not respond to topical steroids.