A Comprehensive Study of the Immunophenotype and its Clinicopathologic Significance in Adult T-Cell Leukemia/Lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell tumor caused by human T-lymphotropic virus type 1 (HTLV-1). The typical ATLL immunophenotypes are described in the 2017 World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues (positive: CD2, CD3, CD5, CD4, and CD25; negative: CD7, CD8, and cytotoxic markers; and partially positive: CD30, CCR4, and FOXP3). However, limited studies are available on the expression of these markers, and their mutual relationship remains unknown. Furthermore, the expression status of novel markers associated with T-cell lymphomas, including Th1 markers (T-bet and CXCR3), Th2 markers (GATA3 and CCR4), T follicular helper markers (BCL6, PD1, and ICOS), and T-cell receptor (TCR) markers, and their clinicopathologic significance is unclear. In this study, we performed >20 immunohistochemical stains in 117 ATLL cases to determine the comprehensive immunophenotypic profile of ATLL, which were compared on the basis of clinicopathologic factors, including morphologic variants (pleomorphic vs anaplastic), biopsy locations, treatments, Shimoyama classification-based clinical subtype, and overall survival. CD3+/CD4+/CD25+/CCR4+ was considered a typical immunophenotype of ATLL, but approximately 20% of cases did not conform to this pattern. Simultaneously, the following new findings were obtained: (1) most cases were negative for TCR-ß and TCR-δ (104 cases, 88.9%), indicating the usefulness of negative conversion of TCR expression to provide differentiation from other T-cell tumors; (2) the positivity of CD30 and CD15 and the negativity of FOXP3 and CD3 were significantly associated with anaplastic morphology; and (3) atypical cases, such as T follicular helper marker-positive (12 cases, 10.3%) and cytotoxic molecule-positive cases (3 cases, 2.6%), were identified. No single markers could predict the overall survival among patients with acute/lymphoma subtypes of ATLL. The results of this study illustrate the diversity of ATLL phenotypes. In T-cell tumors occurring in HTLV-1 carriers, the possibility of ATLL should not be eliminated even when the tumor exhibits an atypical phenotype, and the confirmation of HTLV-1 in the tissue is recommended.

Unusual presentation of breast adenoid cystic carcinoma resembling adenomyoepithelioma with multiple distinct foci.

We describe an unusual case of multifocal breast adenoid cystic carcinoma (AdCC) with adenomyoepitheliomatous morphology. Most breast AdCCs are unifocal and only four cases of multifocal AdCC have been reported previously, however, to our best knowledge, multifocality in AdCC confirmed by molecular analysis has not been reported, so this report adds to the literature on this unique presentation. An 80-year-old woman presented with a left breast mass at 1 o'clock and non-mass enhancement lesion at 5 o'clock on imaging. Incisional biopsy at 1 o'clock showed AdCC based on histopathological features and MYB rearrangement by fluorescent in situ hybridization (FISH). As AdCC involved the margins and the non-mass enhancing lesion remained, mastectomy was performed. Microscopically, the lesion at 5 o'clock demonstrated multinodularity and a biphasic epithelial-basaloid/myoepithelial pattern. Although histological features resembled adenomyoepithelioma, MYB rearrangement was identified on FISH, so the 5 o'clock lesion was also diagnosed as AdCC showing an adenomyoepitheliomatous pattern. This unusual presentation is a potential diagnostic pitfall, so pathologists should consider AdCC as a possible differential diagnosis of multifocal basaloid breast tumors with adenomyoepitheliomatous features.

Hepatocellular Carcinoma in a Patient With Crohn's Disease.

A 44-year-old woman with a 26-year history of Crohn's disease (CD) presented with intermittent fever, vomiting, and watery diarrhea. Her medication included an elemental diet, mesalazine, and infliximab. Liver profile and viral hepatitis markers were normal. Computed tomography scans showed a hepatic tumor by chance. Serum tumor markers disclosed elevated protein induced by vitamin K absence-II. With a diagnosis of hepatocellular carcinoma (HCC), she underwent a hepatic resection of the tumor, revealing well-to-moderately differentiated HCC. The nontumor region of the liver disclosed the absence of cirrhosis or other diseases. Here, the development of HCC in CD without underlying liver diseases is discussed with a review of the literature.

Clinicopathological features of adult T-cell leukemia/lymphoma with HTLV-1-infected Hodgkin and Reed-Sternberg-like cells.

Hodgkin and Reed-Sternberg (HRS) cells, a hallmark of classic Hodgkin lymphoma (CHL), are occasionally detected in non-Hodgkin lymphomas, including adult T-cell leukemia/lymphoma (ATLL), a lymphoid neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1). HRS-like cells associated with ATLL have been described to be of B-cell lineage and infected with Epstein-Barr virus (EBV), not HTLV-1. We herein describe clinicopathological findings in 8 cases (4 males and 4 females; median age, 73 years [range, 55-81 years]) of ATLL with HTLV-1-infected HRS-like cells identified by ultrasensitive RNA in situ hybridization for HTLV-1 basic leucine zipper factor (HBZ-ISH), a specific viral transcript of HTLV-1. All patients showed nodal or mediastinal lesions, and 5 of the 8 patients were at an advanced disease stage. HRS-like cells were positive for CD30, CD15, MUM1, CD25, and HBZ-ISH and negative for B-cell markers, including PAX5, pan-T-cell antigens, and EBV in all cases. Five cases were positive for CD4, and 6 cases were positive for fascin. HBZ was identified in both HRS-like cells and surrounding lymphoid cells in 1 case with an aggressive clinical course and only HRS-like cells in 7 cases, most of whom showed a clinical response regardless of the chemotherapeutic regimen. Even though the definitive lineage typing of the HTLV-1-infected HRS cells is one of the limitations of this study in the absence of single-cell microdissection for polymerase chain reaction analysis, the combination of diffuse HBZ-ISH positivity and negativity for PAX5 and EBV deemed these cases distinct from CHL arising in HTLV-1 carriers.