# A Late Testicular Relapse in an Adult with Acute Lymphoblastic Leukemia, 5 Years after the Diagnosis and 4 Years after Allotransplant—A Rare Case

## TL;DR

A 56-year-old man experienced a rare late testicular relapse of acute lymphoblastic leukemia five years after treatment and a stem cell transplant.

## Contribution

This case highlights the rare occurrence of isolated testicular relapse in adult ALL patients long after initial treatment.

## Key findings

- Testicular relapse occurred five years after diagnosis and four years after allotransplant.
- Immunophenotyping confirmed the relapse was consistent with the original ALL T subtype.
- No systemic leukemia relapse was detected in bone marrow tests.

## Abstract

Acute lymphoblastic leukemia (ALL) is a malignant disorder of lymphoid progenitor cells that affects both pediatric and adult populations. Although isolated testicular or any other organ recurrence can occur in the pediatric population, it is rare in adults. We present images for an atypical case of the late testicular recurrence of acute lymphoblastic leukemia in a 56-year-old man previously diagnosed with ALL pro-T who was in remission following polychemotherapy (GMALL 2013 protocol) and the allotransplantation of peripheral blood stem cells from a related donor. Five years later (2022), the unilateral testicular relapse of ALL was suspected by imaging and diagnosed by immunophenotyping from sperm fluid infiltrated with atypical cells with an immunophenotype concordant with that of the underlying disease (ALL T). Bone marrow aspiration and biopsy showed no evidence of systemic leukemia relapse. Testicular ablation or chemotherapy and irradiation were considered. Given the strictly testicular relapse, orchiectomy would have been useful, but given the abdominal adenopathy, a chemotherapy course with HyperCVAD Block A was first required. Testicular relapse can occur at any age, and the recognition of this is important as it may be the first manifestation of systemic relapse.