罕見的睪丸瀰漫性Ｂ細胞淋巴瘤: 大腸癌化療後的隱憂？

唐慈翊^1-2、張顥瀚^1,2

高雄醫學大學附設醫¹泌尿科;

 高雄醫學大學醫學院²泌尿學科

Hidden Enemy: Rare Testicular diffuse large B-cell lymphoma in a Colorectal Cancer Survivor

Tsz-Yi Tang^1-2, Hao-Han Chang^1,2

¹Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan;

²Department of Urology, Kaohsiung Medical University, Kaohsiung, Taiwan

Case Report 

            A 61-year-old male with a history of sigmoid colon adenocarcinoma (pT4aN1cM0, stage IIIB) initially presented in December 2019 with sigmoid colonic obstruction, for which he underwent sigmoid colostomy and completed twelve cycles of FOLFOX6 chemotherapy without significant adverse events.

            This time, he presented with a painless left scrotal enlargement noted incidentally. Physical examination revealed a left extratesticular mass with testicular enlargement but without tenderness. Scrotal ultrasonography revealed a heterogeneous left testicular mass with microcalcifications and an adjacent extratesticular mass. Laboratory investigations, including serum tumor markers (beta-human chorionic gonadotropin, lactate dehydrogenase, and alpha-fetoprotein), were within normal limits. Abdominal computed tomography (CT) imaging revealed a 5.1 cm enhancing soft tissue lesion in the left scrotum without evidence of retroperitoneal or pelvic lymphadenopathy (Figure 1). Under the impression of left extratesticular tumor, left radical orchiectomy was performed. In Figure 2, a gross view image reveals a firm, yellowish tumor located outside the left testis. Panel A shows the normal texture of the testis, while Panel B highlights the extratesticular yellowish tumor, clearly distinct from the normal testicular tissue. Histopathologic evaluation of the orchiectomy specimen revealed diffuse large B-cell lymphoma (DLBCL), non-germinal center B-cell type, involving the paratesticular soft tissue, with the epididymis and spermatic cords unaffected. Immunohistochemistry demonstrated positivity for CD20, BCL-2, c-myc, and MUM-1, while CD3, BCL-6, CD10, and Epstein-Barr virus (EBER) in situ hybridization were negative. Due to the diagnosis of diffuse large B-cell lymphoma, the patient was transferred to the hematology ward for further PET imaging and initiation of chemotherapy with the R-CHOP regimen.

Conclusion

We report a rare case of diffuse large B-cell lymphoma in a patient with a history of sigmoid colon adenocarcinoma, successfully managed with left radical orchiectomy. The lack of lymphadenopathy and the normal serum tumor markers are notable features, underscoring the need for comprehensive evaluation of scrotal masses in patients with a history of malignancy, as extranodal lymphoma may mimic primary testicular tumors.