Immunohistochemistry of the oncofetal protein IMP3 is helpful in the diagnosis of intravascular large B‐cell lymphoma using skin biopsy

Abstract

Background The oncofetal protein insulin‐like growth factor 2 mRNA binding protein‐3 (IMP3) is expressed in various cancers. In this study, we examined the diagnostic utility of IMP3 immunohistochemistry in the context of intravascular large B‐cell lymphoma (IVL). Methods We obtained 25 skin biopsy (SB) specimens diagnosed as IVL and nine IVL‐negative SB specimens from 27 IVL patients. Additionally, 27 negative SB specimens from 26 non‐IVL patients were obtained from our pathology archives. We performed IMP3 immunohistochemistry on these 61 SB specimens, considering IMP3 expression in any mononuclear cell as positive. In selected cases, triple immunostaining for IMP3, PAX5, and CD34 was performed to analyze the origin and location of IMP3‐positive cells. Results IMP3 was expressed in most intravascular lymphoma cells in all the 25 SB specimens diagnosed as IVL. Furthermore, our evaluation revealed the presence of intravascular IMP3‐positive B‐cells in five of the nine negative SB specimens from IVL patients; however, this was not observed in the 27 SB specimens from non‐IVL patients. Conclusion IMP3 was expressed in most IVL cells, and IMP3 immunohistochemistry could serve as a sensitive diagnostic aid for detecting IVL cells in SB.

Insulin-like Growth Factor II mRNA-binding Protein 3 is a Highly Sensitive Marker for Intravascular Large B-cell Lymphoma

“…14,31 However, despite its diagnostic difficulty, no IHC marker has been previously reported to differentiate IVLBCL from reactive B cells. The present study demonstrated that all 111 samples of IVLBCL expressed IMP3, and combined with the results of the previous study, 22 all 136 pathology specimens diagnosed with IVLBCL were positive for IMP3. Moreover, IMP3 highlighted cells suspicious for IVLBCL in 26.8% (11/41) of pathological specimens obtained from IVLBCL patients, which were diagnosed as negative for IVLBCL in routine practice.…”

“…Using a single institutional cohort, we performed immunohistochemistry (IHC) for IMP3 on skin biopsies and found IMP3 to be a highly sensitive marker for IVLBCL in skin biopsies. 22 Considering that the clinical presentation and diagnosis of IVLBCL are not limited to the skin, we sought to expand on these findings to capture the full clinical and pathological presentation of IVLBCL. Here, we used a multi-institutional cohort to analyze the utility of IMP3 IHC in the diagnosis of IVLBCL in various organs and validated it using double staining with paired box 5 (PAX5).…”

“…In our practice, we use IMP3 as a useful marker for these lymphomas, especially in small biopsy specimens with low numbers of tumor cells. Using a single institutional cohort, we performed immunohistochemistry (IHC) for IMP3 on skin biopsies and found IMP3 to be a highly sensitive marker for IVLBCL in skin biopsies 22 …”