FISH analysis using MYC break-apart probes is a widely used technique to assess for MYC rearrangement (MYC-R). Occasionally, FISH results in atypical signal patterns, such as gain or loss of 5^ʹMYC or 3^ʹMYC. The clinical impact and/or relationship of these atypical signal patterns to MYC-R are unknown. In this study, we assessed 35 patients who had aggressive B-cell lymphomas and exhibited atypical FISH signal patterns: 3^ʹMYC deletion (n = 16) or 3^ʹMYC deletion plus 5^ʹMYC amplification (n = 5), 5^ʹMYC gain (n = 10), 5^ʹMYC deletion (n = 3), and 3^ʹMYC gain (n = 1). For comparison, we also included 9 patients who showed an unbalanced MYC-R. Patients with 5^ʹMYC gain showed MYC expression and were often refractory to chemotherapy (n = 7) or had early relapse (n = 2). By contrast, lymphomas with 3^ʹMYC deletion were negative or had low expression of MYC (16 of 18), and patients often responded to chemotherapy (16 of 19). The median event-free survival was 24, 6, and 4 months for patients with 3^ʹMYC deletion, 5^ʹMYC gain and unbalanced MYC-R, respectively (p = 0.0048). We conclude that 5^ʹMYC gain is associated with MYC expression and a poorer prognosis and likely represents an unbalanced MYC-R. By contrast, 3^ʹMYC deletions are not associated with MYC expression or a poorer prognosis and this finding may be unrelated to MYC-R.

使用MYC分离探针的FISH 分析是一种广泛使用的技术，用于评估MYC重排 ( MYC -R)。有时，FISH 会导致非典型信号模式，例如 5 ^ʹ MYC或 3 ^ʹ MYC 的增益或丢失。这些非典型信号模式与MYC -R的临床影响和/或关系尚不清楚。在这项研究中，我们评估了 35名患有侵袭性 B 细胞淋巴瘤并表现出非典型 FISH 信号模式的患者：3'MYC缺失（ⁿ = 16  ）或 3'MYC^缺失加上^5'MYC扩增（n = 5), 5 ^ʹ MYC增益 ( n  = 10), 5 ^ʹ MYC缺失 ( n  = 3), 和 3 ^ʹ MYC增益 ( n  = 1)。为了进行比较，我们还纳入了 9 名表现出不平衡的MYC -R 的患者。具有 5 ^ʹ MYC增益的患者表现出 MYC 表达，并且通常对化疗具有抵抗力 ( n  = 7) 或早期复发 ( n  = 2)。相比之下，具有 3 ^ʹ MYC 的淋巴瘤缺失为阴性或 MYC 表达低（18 人中有 16 人），患者通常对化疗有反应（19 人中有 16 人）。^{3 '} MYC缺失、5 ^' MYC增加和MYC -R不平衡患者的中位无事件生存期分别为 24、6 和 4 个月( p  = 0.0048)。我们得出结论，5 ^ʹ MYC增益与 MYC 表达和较差的预后相关，并且可能代表不平衡的MYC -R。相比之下，3'MYC^缺失与MYC表达或较差的预后无关，并且这一发现可能与MYC -R 无关。