Primary Osseous Fibroblastic Reticular Cell Tumour of the Proximal Humerus: A Rare Case Report and Review of Pathogenesis: Primary Osseous Fibroblastic Reticular Cell Tumour

Xiang Yin Ng; Eyrique Goh Boay Heong; Adrian Teoh Zhen Yi; Shir Lee Ong; Suryasmi Duski

Authors

Xiang Yin Ng Hospital Kuala Lumpur Malaysia
Eyrique Goh Boay Heong Hospital Kuala Lumpur Malaysia
Adrian Teoh Zhen Yi Hospital Kuala Lumpur Malaysia
Shir Lee Ong Hospital Kuala Lumpur Malaysia
Suryasmi Duski Hospital Kuala Lumpur Malaysia

Keywords:

Oncology, Fibroblastic, Bone Tumour, Humerus

Abstract

Fibroblastic reticular cell tumour (FRCT) is an exceptionally rare neoplasm arising from specialised fibroblastic reticular cells of the lymphoid stromal network. Primary involvement of bone is extraordinarily uncommon, with only isolated cases reported in the literature. We present a case of a 40-year-old woman with a destructive lesion of the proximal humerus subsequently diagnosed as FRCT. The patient was treated with neoadjuvant chemotherapy followed by wide surgical excision and endoprosthetic reconstruction. This report highlights the clinical, radiological, pathological, and therapeutic challenges associated with this rare entity and reviews emerging concepts of FRCT pathogenesis, including ectopic stromal differentiation, chemokine-driven microenvironmental mimicry, and mismatch-repair deficiency. This case contributes to the limited body of literature on primary osseous FRCT and underscores the importance of multidisciplinary management.

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Primary Osseous Fibroblastic Reticular Cell Tumour of the Proximal Humerus: A Rare Case Report and Review of Pathogenesis