Pathological Confirmation Of Apparent Metastatic Disease Is Essential: Incidentally Diagnosed Low Grade B Cell Lymphomas In Patients With Solid Tumors

The detection of skeletal metastasis, enlarged lymph nodes or parenchymal lesions in patients (pts) with established solid tumors most commonly denotes advanced stage disease. If not confirmed histologically, a subset of pts might be over staged and mismanaged palliatively.

We report 7 cases of low-grade B cell lymphomas diagnosed in a bone, lymph node or lung biopsy during staging workup in patients with suspected metastatic solid tumors.

All pts were men aged 41 to 80 yo diagnosed with: non-small cell lung (NSCL), prostate, lip squamous cell, bladder, renal cell cancer (CA) and nasal adenoid cystic carcinoma. Imaging studies done during initial workup or follow up after resection of the primary tumor revealed bone metastasis, lymphadenopathy or lung nodules suggesting advanced stage of the primary CA. Invasive workup of the lesions in question revealed incidental low-grade B cell lymphomas (2 low grade lymphomas of bone, 2 CLL/SLL, 1 BALT, 1 marginal zone and 1 nodular lymphocyte predominant Hodgkin lymphoma). In all cases, this led to down staging and changed the management of the solid CA. Surgical resection of the tumor was done after it was down staged from non-resectable to resectable in 2 pts with head/neck CA; 1 pt with NSCL was down staged from stage IV to IIIA and received chemo/radiotherapy; 1 pt with prostate CA was down staged from stage IV to I; 3 pts were down staged from stage IV and were in remission from previously resected solid tumors. Only 2 pts required therapy for the newly diagnosed lymphoma. Avidity of the lesions revealed SUV ranging from 1.28 to 14.11 in the bone and from 2.17 to 6.98 in the lymph nodes.

Accurate staging of pts with solid tumors is critical in defining optimal goals of therapy. The growing use of PET/CT scans results in a higher rate of incidentally detected bone lesions or lymphadenopathy. Whereas a number of solid tumors readily spread to bone and lymph nodes, a spectrum of indolent lymphoid disorders may coexist in pts with established solid tumors. These lymphomas may remain asymptomatic for years. This might be misinterpreted as advanced stage solid tumor unless confirmed histologically.

No relevant conflicts of interest to declare.