一名51岁男性患者，患有3年的外源性睾酮颗粒注射治疗(TRT)左臀部，来进行常规皮肤检查。虽然患者报告了TRT注射部位的反复引流，但他仍然每6个月接受重复植入。体格检查中，在左臀部发现了一个12毫米的不规则、棕色的斑块，形成了不清晰的瘀伤和波动性皮下斑块，有一个窦道引流浆液。对色素斑块进行了活检，结果显示原位恶性黑色素瘤，因此安排了广泛的局部切除。在手术中观察到活检部位周围的皮下脂肪坏死，并去除了大约18平方厘米的区域进行病理评估。组织学检查显示弥漫性的皮下肉芽肿浸润，扇形和小叶性脂肪坏死，以及周围的脓肿组织和血铁沉着（图1A和B）。在同一块被去除组织的另一块标本中，类似的发现表明肉芽肿性脂肪坏死。周期酸-舍夫（PAS），革兰氏染色和酸性快速杆菌（AFB）染色未检出微生物。在手术探查过程中，发现了六个异物，并确认为未溶解的睾酮颗粒。患者被转诊至伤口护理中心，但最终失去了后续随访。

A 51-year-old man with a 3-year history of exogenous testosterone pellet injections to the left buttock presented for routine skin examination. While the patient reported recurrent drainage from the site of testosterone replacement therapy (TRT) injections, he continued to receive repeated implantations every 6 months. On physical examination, a 12-mm irregular, brown macule was identified within a poorly demarcated, ecchymotic, and fluctuant subcutaneous plaque on the left buttock with a sinus tract draining serosanguinous fluid. The pigmented lesion was biopsied, revealing malignant melanoma in situ; hence, a wide local excision was scheduled. During the procedure, necrotic subcutaneous fat was observed surrounding the site of biopsy, and a region measuring 18 cm2 approximately was debrided and submitted for pathologic evaluation. Histopathologic examination revealed a diffused subcutaneous granulomatous infiltrate with septal and lobular panniculitis and fat necrosis as well as peripherally palisading histiocytes and hemosiderin deposition (Figures 1A and B). Similar findings were observed in another specimen from the same segment of debrided tissue, compatible with granulomatous panniculitis. Periodic acid-Schiff (PAS), Gram's, and acid-fast bacilli (AFB) stains revealed no microorganisms. During surgical exploration, six foreign bodies were discovered and identified as undissolved testosterone pellets. The patient was referred to a wound care center, but ultimately lost to follow-up.