A 60-year-old man was admitted to an Australian tertiary trauma hospital with a pre-tibial wound infection two years following an open right tibial fracture. Previous management involved intra-medullary nail fixation, 2nd stage Masquelet procedure and local transposition flap for soft-tissue coverage. His history was significant for primary CNS lymphoma (PCNSL), managed with induction chemotherapy and consolidation whole brain radiotherapy. He was cleared of his PCNSL one year prior to this presentation.
The patient described ulceration and cellulitis of the flap that failed to respond to oral antibiotics and underwent surgical debridement and tissue biopsy. Intraoperative findings demonstrated fibrinous material deep to the flap, no infected collection. Staphylococcus lugdunensis was cultured from bone and soft tissue. Histological examination demonstrated sheets of large atypical lymphocytes infiltrating necrotic connective tissue. Tumour cells showed strong immunoreactivity for B cell markers CD20 and CD79a, consistent with diffuse large B cell lymphoma. Staging FDG-PET demonstrated multiple foci of uptake in the right lower limb consistent with Lymphoma, largest within the transposition flap, no further sites of distant metastasis. Limb salvage was attempted with debridement, exchange of metalware, and split thickness skin graft reconstruction once granulating. The patient underwent salvage chemotherapy with good response and is awaiting autologous stem cell transplantation.
This is the first presented case of relapsed PCNSL or tumour metastasis in a reconstructive flap. Consideration of malignancy as a differential diagnosis in chronic non-healing leg wounds is essential and underlies the need for routine, histological examination of chronic wounds.