Syphilis in Hematopathology Practice: A Diagnostic Challenge.

CONTEXT.­: Syphilis, a reemerging disease caused by spirochete Treponema pallidum, is becoming more frequent in surgical pathology and hematopathology practices. Hematopathologists typically receive lymph node biopsies from patients with syphilis who have localized or diffuse lymphadenopathy. Occasionally, syphilis infection in the aerodigestive tract can show a prominent lymphoplasmacytic infiltrate and mimic lymphoma. Besides the varying and occasional atypical morphology, the fact that clinical suspicion tends to be low or absent when histologic evaluation is requested adds to the importance of making this diagnosis. OBJECTIVE.­: To summarize histologic features of syphilitic lymphadenitis and syphilis lesions in the aerodigestive tract, and to review differential diagnosis and potential diagnostic pitfalls. DATA SOURCES.­: Literature review via PubMed search. CONCLUSIONS.­: Characteristic histologic findings in syphilitic lymphadenitis include thickened capsule with plasma cell-rich inflammatory infiltrate, reactive follicular and paracortical hyperplasia with prominent lymphoplasmacytic infiltrate, and vasculitis. Lymph nodes, however, can show a number of other nonspecific histologic features, which frequently makes the diagnosis quite challenging. In the aerodigestive tract, syphilis is characterized by plasma cell-rich infiltrates. Immunohistochemistry for T pallidum is the preferred method for detecting spirochetes; however, this immunohistochemical stain shows cross-reactivity with other treponemal and commensal spirochetes. Differential diagnosis of syphilis in lymph nodes and the aerodigestive tract is broad and includes reactive, infectious, and neoplastic entities. Pathologists should be aware of the histologic features of syphilis and keep this challenging entity in the differential diagnosis.

ERG amplification is a secondary recurrent driver event in myeloid malignancy with complex karyotype and TP53 mutations.

ERG is a transcription factor encoded on chromosome 21q22.2 with important roles in hematopoiesis and oncogenesis of prostate cancer. ERG amplification has been identified as one of the most common recurrent events in acute myeloid leukemia with complex karyotype (AML-CK). In this study, we uncover three different modes of ERG amplification in AML-CK. Importantly, we present evidence to show that ERG amplification is distinct from intrachromosomal amplification of chromosome 21 (iAMP21), a hallmark segmental amplification frequently encompassing RUNX1 and ERG in a subset of high-risk B-lymphoblastic leukemia. We also characterize the association with TP53 aberrations and other chromosomal aberrations, including chromothripsis. Lastly, we show that ERG amplification can initially emerge as subclonal events in low-grade myeloid neoplasms. These findings demonstrate that ERG amplification is a recurrent secondary driver event in AML and raise the tantalizing possibility of ERG as a therapeutic target.

Cyclophosphamide treatment in active multiple sclerosis.

OBJECTIVE: Cyclophosphamide (CYC) is an alkylating agent with immunosuppressive effect by inhibiting DNA synthesis and producing apoptosis used in many autoimmune diseases, including multiple sclerosis (MS). Here, we analyze the efficacy of CYC treatment in relapsing-remitting (RRMS) and active secondary progressive MS (SPMS) in our center with a monthly scheme. METHODS: Patients with MS treated with CYC and a follow up of at least 36 months were eligible for inclusion. All participants had received a standard CYC regimen. The EDSS score mean annualized relapse rate (ARR) and progression index (PI) were measured as efficacy outcomes at 12, 24, and 36 months. Outcomes were also analyzed comparing disease course and activity. RESULTS: A total of 16 patients were included (50% male, 18.75% RRMS and 81.25% SPMS). EDSS remained stable along the follow-up period, with 62.5% improving or maintaining the same EDSS score at 12 months. PI decreased 14% and 21% at 12 and 24-36 months of follow-up, respectively. ARR decreased 20% after 12 months, 19% after 24 months, and 30.23% after 36 months. Median differences in ARR were higher in patients with high relapse activity (0.60 vs 0.07, p = 0.001) and malignant course (0.60 vs 0.17, p = 0.027). PI also differed with higher mean differences in patients with high relapse activity (0.70 vs 0.03, p = 0.016) and malignant course (1.17 vs 0.03, p = 0.003). CONCLUSIONS: CYC continues to be a valid therapeutic option, especially in regions with limited access to high-efficiency therapies particularly in patients with high relapsing activity and malignant course.