Raul Perret1, Michael Michal2,3, Richard A Carr4, Valérie Velasco1, Marian Švajdler2,3, Marie Karanian5,6, Alexandra Meurgey5, Sandrine Paindavoine5, Isabelle Soubeyran1, Jean-Michel Coindre1,7, Romain Boidot8, Céline Charon-Barra9, Damien Geneste10, Noelle Weingertner11, Daniel Pissaloux5,6, Franck Tirode6, Jessica Baud7,12, François Le Loarer1,7,12. 1. Department of Biopathology, Institut Bergonié, Bordeaux, France. 2. Department of Pathology, Faculty of Medicine in Plzen, Charles University, Plzen, Czech Republic. 3. Department of Pathology and Molecular Genetics, Bioptical Laboratory Ltd, Plzen, Czech Republic. 4. Department of Pathology, Warwick Hospital, Warwick, UK. 5. Department of Biopathology, Centre Leon Berard, Lyon, France. 6. Université Lyon, Claude Bernard Lyon 1 University, Lyon, France. 7. University of Bordeaux, Talence, France. 8. Department of Tumor Biology and Pathology, Molecular Biology Unit, Centre Georges-François Leclerc, Dijon, France. 9. Department of Tumor Biology and Pathology, Pathology Unit, Centre Georges-François Leclerc, Dijon, France. 10. Department of Bioinformatics, Institut Bergonié, Bordeaux, France. 11. Department of Pathology, Strasbourg Regional University Hospital (Hautepierre Hospital), Strasbourg, France. 12. INSERM U1218, Action Unit, Bordeaux, France.
Abstract
AIMS: Superficial CD34-positive fibroblastic tumor (SCD34FT) and PRDM10-rearranged soft tissue tumor (PRDM10-STT) are rare mesenchymal tumors. These lesions have clinicopathological similarities, but their relationship remains controversial. This study aimed to characterise a series of cases of SCD34FT and PRDM10-STT. METHODS AND RESULTS: Ten lesions each of SCD34FT and PRDM10-STT were studied using immunohistochemistry, array-comparative genomic hybridisation (aCGH), RNA sequencing and exome sequencing. Tumors mainly occurred in young adults, were generally small (< 5 cm) and arose predominantly in the superficial soft tissues of the lower extremities. Follow-up data were available in 15 cases (SCD34FT, n = 7, median 16 months; PRDM10-STT, n = 8, median 14 months), local recurrences occurred in four cases (SCD34FT, two of 10; PRDM10-STT, two of 10), while no distant spread was documented. Morphologically, tumors were relatively well-circumscribed and composed of sheets and fascicles of spindle and pleomorphic cells showing low mitotic activity (< 1/mm²) without necrosis. Other findings included: granular cell change, lipoblast-like cells, ectatic blood vessels with fibrinous material, myxoid stromal changes, metaplastic bone and increased mitotic activity (> 1/mm²). All tumors diffusely expressed CD34, while pan-keratin and desmin were commonly seen focally. SynCAM3 was diffusely expressed in 12 cases (SCD34FT, n = 5; PRDM10-STT, n = 7), independently of fusion status. aCGH profiles were 'flat' (PRDM10-STT, n = 4; SCD34FT, n = 2) and exome sequencing showed no recurrent pathogenic mutations (PRDM10-STT, n = 2; SCD34FT, n = 4). Overall, the only morphological features seen exclusively in PRDM10-STT were myxoid stromal changes (three of 10) and metaplastic bone (two of 10). CONCLUSION: We expand the current knowledge on PRDM10-STT and SCD34FT and provide additional evidence for considering them as overlapping entities.
AIMS: Superficial CD34-positive fibroblastic tumor (SCD34FT) and PRDM10-rearranged soft tissue tumor (PRDM10-STT) are rare mesenchymal tumors. These lesions have clinicopathological similarities, but their relationship remains controversial. This study aimed to characterise a series of cases of SCD34FT and PRDM10-STT. METHODS AND RESULTS: Ten lesions each of SCD34FT and PRDM10-STT were studied using immunohistochemistry, array-comparative genomic hybridisation (aCGH), RNA sequencing and exome sequencing. Tumors mainly occurred in young adults, were generally small (< 5 cm) and arose predominantly in the superficial soft tissues of the lower extremities. Follow-up data were available in 15 cases (SCD34FT, n = 7, median 16 months; PRDM10-STT, n = 8, median 14 months), local recurrences occurred in four cases (SCD34FT, two of 10; PRDM10-STT, two of 10), while no distant spread was documented. Morphologically, tumors were relatively well-circumscribed and composed of sheets and fascicles of spindle and pleomorphic cells showing low mitotic activity (< 1/mm²) without necrosis. Other findings included: granular cell change, lipoblast-like cells, ectatic blood vessels with fibrinous material, myxoid stromal changes, metaplastic bone and increased mitotic activity (> 1/mm²). All tumors diffusely expressed CD34, while pan-keratin and desmin were commonly seen focally. SynCAM3 was diffusely expressed in 12 cases (SCD34FT, n = 5; PRDM10-STT, n = 7), independently of fusion status. aCGH profiles were 'flat' (PRDM10-STT, n = 4; SCD34FT, n = 2) and exome sequencing showed no recurrent pathogenic mutations (PRDM10-STT, n = 2; SCD34FT, n = 4). Overall, the only morphological features seen exclusively in PRDM10-STT were myxoid stromal changes (three of 10) and metaplastic bone (two of 10). CONCLUSION: We expand the current knowledge on PRDM10-STT and SCD34FT and provide additional evidence for considering them as overlapping entities.
Authors: Florian Puls; Jodi M Carter; Nischalan Pillay; Thomas A McCulloch; Vaiyapuri P Sumathi; Pehr Rissler; Henrik Fagman; Magnus Hansson; Fernanda Amary; Roberto Tirabosco; Linda Magnusson; Jenny Nilsson; Adrienne M Flanagan; Andrew L Folpe; Fredrik Mertens Journal: Mod Pathol Date: 2021-12-30 Impact factor: 7.842