The Genetic Basis of Hepatosplenic T-cell Lymphoma.

Hepatosplenic T-cell lymphoma (HSTL) is a rare and lethal lymphoma; the genetic drivers of this disease are unknown. Through whole-exome sequencing of 68 HSTLs, we define recurrently mutated driver genes and copy-number alterations in the disease. Chromatin-modifying genes, including SETD2, INO80, and ARID1B, were commonly mutated in HSTL, affecting 62% of cases. HSTLs manifest frequent mutations in STAT5B (31%), STAT3 (9%), and PIK3CD (9%), for which there currently exist potential targeted therapies. In addition, we noted less frequent events in EZH2, KRAS, and TP53SETD2 was the most frequently silenced gene in HSTL. We experimentally demonstrated that SETD2 acts as a tumor suppressor gene. In addition, we found that mutations in STAT5B and PIK3CD activate critical signaling pathways important to cell survival in HSTL. Our work thus defines the genetic landscape of HSTL and implicates gene mutations linked to HSTL pathogenesis and potential treatment targets.Significance: We report the first systematic application of whole-exome sequencing to define the genetic basis of HSTL, a rare but lethal disease. Our work defines SETD2 as a tumor suppressor gene in HSTL and implicates genes including INO80 and PIK3CD in the disease. Cancer Discov; 7(4); 369-79. ©2017 AACR.See related commentary by Yoshida and Weinstock, p. 352This article is highlighted in the In This Issue feature, p. 339.

Relapsed or Refractory Double-Expressor and Double-Hit Lymphomas Have Inferior Progression-Free Survival After Autologous Stem-Cell Transplantation.

Purpose Double-hit lymphomas (DHLs) and double-expressor lymphomas (DELs) are subtypes of diffuse large B-cell lymphoma (DLBCL) associated with poor outcomes after standard chemoimmunotherapy. Data are limited regarding outcomes of patients with relapsed or refractory (rel/ref) DEL or DHL who undergo autologous stem-cell transplantation (ASCT). We retrospectively studied the prognostic impact of DEL and DHL status on ASCT outcomes in patients with rel/ref DLBCL. Methods Patients with chemotherapy-sensitive rel/ref DLBCL who underwent ASCT at two institutions and in whom archival tumor material was available were enrolled. Immunohistochemistry for MYC, BCL2, and BCL6 and fluorescence in situ hybridization (FISH) for MYC were performed. In cases with MYC rearrangement or copy gain, FISH for BCL2 and BCL6 was also performed. Results A total of 117 patients were included; 44% had DEL and 10% had DHL. DEL and DHL were associated with inferior progression-free survival (PFS), and DHL was associated with poorer overall survival (OS). The 4-year PFS in patients with DEL compared with those with non-DEL was 48% versus 59% ( P = .049), and the 4-year OS was 56% versus 67% ( P = .10); 4-year PFS in patients with DHL compared with those with non-DHL was 28% versus 57% ( P = .013), and 4-year OS was 25% versus 61% ( P = .002). The few patients with concurrent DEL and DHL had a poor outcome (4-year PFS, 0%). In multivariable models, DEL and DHL were independently associated with inferior PFS, whereas DHL and partial response ( v complete response) at transplant were associated with inferior OS. Conclusion DEL and DHL are both associated with inferior outcomes after ASCT in patients with rel/ref DLBCL. Although ASCT remains a potentially curative approach, these patients, particularly those with DHL, are a high-risk subset who should be targeted for investigational strategies other than standard ASCT.

B-cell Lymphoproliferative Disorders Associated with Primary and Acquired Immunodeficiency.

The diagnosis of lymphoproliferative disorders associated with immunodeficiency can be challenging because many of these conditions have overlapping clinical and pathologic features and share similarities with their counterparts in the immunocompetent setting. There are subtle but important differences between these conditions that are important to recognize for prognostic and therapeutic purposes. This article provides a clinicopathologic update on how understanding of these B-cell lymphoproliferations in immunodeficiency has evolved over the past decade.

De novo congenital melanoma: analysis of 2 cases with array comparative genomic hybridization.

Congenital melanoma is extraordinarily rare, and 3 types have been described: transplacental metastases from the mother, de novo congenital melanoma, and melanoma occurring in association with a congenital melanocytic nevus. We describe 2 reports of array comparative genomic hybridization analysis of de novo congenital melanoma. The first patient was male, and the second was female; both had a scalp lesion present at birth, which grew quickly. The scalp mass from patient 1 showed a heterogeneous, anaplastic melanocytic neoplasm with large size and depth, high mitotic rate, ulceration, and necrosis. The scalp mass from patient 2 showed a broad melanocytic neoplasm with single cell and junctional nested proliferation at the dermal-epidermal junction and cellular, confluent aggregates of highly atypical melanocytes in the dermis with high mitotic rate. Patient 1 had lung and liver metastases detected by radiologic imaging and was treated with cisplatin, vinblastine, and dacarbazine but expired at the age of 5 months. Patient 2 developed a metastasis to the right neck with similar histologic features, and pulmonary metastases were also detected by imaging. Patient 2 is currently alive at the age of 4 years. Array comparative genomic hybridization analysis of the first case revealed loss of chromosomes 3p26.3-p21.31, 5p15.33-q23.1, 11q15.5-q13.2, 14 (complete deletion), and 15q11.1-q22.31. The second case displayed gains in chromosomes 1q21.1-q44, 2p25.3-p11.1, 2q11.1-q37.3, 6p25.3-p11.1, 7p22.3-p11.2, 7q11.1-q36.3, 8p23.3-p11.1, 8q11.1-q24.3, 9p24.3-p11.2, 9q12-q34.3, 11q13.2-q13.4, 13q11-q34, 18p11.32-p11.21, 19p13.3-p11, 19q11-q13.43, 20p13-p11.1, and 20q11.21-q13.33. In both cases, the presence of multiple chromosomal aberrations corroborated the diagnosis of melanoma.

Severe enterocolitis associated with antiepileptic-induced drug reaction with eosinophilia and systemic symptoms.

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare but serious drug-induced reaction with cutaneous, hematologic, and solid-organ injury. Antiepileptic drugs are one of the most common classes of drugs implicated in DRESS. A high morbidity and mortality may result, especially if the offending drug is not withdrawn promptly. Although DRESS may involve many organs, severe involvement of the gastrointestinal tract in DRESS and/or in association with antiepileptic drugs has rarely been reported. We report detailed clinical and histopathologic findings of a fatal case of DRESS syndrome resulting from antiepileptic drug treatment that was accompanied by severe enterocolitis, malabsorption, and cachexia.