We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Branchioma: immunohistochemical and molecular genetic study of 23 cases highlighting frequent loss of retinoblastoma 1 immunoexpression.
- Authors
Bradová, Martina; Thompson, Lester D. R.; Hyrcza, Martin; Vaněček, Tomáš; Grossman, Petr; Michal Jr., Michael; Hájková, Veronika; Taheri, Touraj; Rupp, Niels; Suster, David; Lakhani, Sunil; Nikolov, Dimitar Hadži; Žalud, Radim; Skálová, Alena; Michal, Michal; Agaimy, Abbas
- Abstract
Branchioma is an uncommon benign neoplasm with an adult male predominance, typically occurring in the lower neck region. Different names have been used for this entity in the past (ectopic hamartomatous thymoma, branchial anlage mixed tumor, thymic anlage tumor, biphenotypic branchioma), but currently, the term branchioma has been widely accepted. Branchioma is composed of endodermal and mesodermal lineage derivatives, in particular epithelial islands, spindle cells, and mature adipose tissue without preexistent thymic tissue or evidence of thymic differentiation. Twenty-three branchiomas were evaluated morphologically. Eighteen cases with sufficient tissue were assessed by immunohistochemistry, next-generation sequencing (NGS) using the Illumina Oncology TS500 panel, and fluorescence in situ hybridization (FISH) using an RB1 dual-color probe. All cases showed a biphasic morphology of epithelial and spindle cells with intermingled fatty tissue. Carcinoma arising in branchioma was detected in three cases. The neoplastic cells showed strong AE1/3 immunolabeling (100%), while the spindle cells expressed CD34, p63, and SMA (100%); AR was detected in 40–100% of nuclei (mean, 47%) in 14 cases. Rb1 showed nuclear loss in ≥ 95% of neoplastic cells in 16 cases (89%), while two cases revealed retained expression in 10–20% of tumor cell nuclei. NGS revealed a variable spectrum of likely pathogenic variants (n = 5) or variants of unknown clinical significance (n = 6). Loss of Rb1 was detected by FISH in two cases. Recent developments support branchioma as a true neoplasm, most likely derived from the rudimental embryological structures of endoderm and mesoderm. Frequent Rb1 loss by immunohistochemistry and heterozygous deletion by FISH is a real pitfall and potential confusion with other Rb1-deficient head and neck neoplasms (i.e., spindle cell lipoma), especially in small biopsy specimens.
- Subjects
HEAD &; neck cancer; BENIGN tumors; FLUORESCENCE in situ hybridization; RETINOBLASTOMA; ADIPOSE tissues
- Publication
Virchows Archiv: European Journal of Pathology, 2024, Vol 484, Issue 1, p103
- ISSN
0945-6317
- Publication type
Article
- DOI
10.1007/s00428-023-03697-1