An extensive debate has existed over the association of sarcoidosis with cancer. In patients with certain malignancies like lymphomas, testicular cancer, lung cancer and melanomas an increased incidence of sarcoidosis has been classically reported (1). Only a single case report of coexistence of sarcoidosis with a gastric plasmacytoma has been described in the literature. The authors present, the second reported case of a plasmacytoma presenting concomitantly with sarcoidosis, and the first reported case occurring in a thoracic medullary plasmacytoma. The sarcoidosis resolved with the treatment of the plasmacytoma.
A 39 year-old previously healthy female presented for evaluation of pleuritic pain in the left lower chest. Chest radiography revealed a lytic lesion on the 9th rib, shown on computed tomography (CT) to be an irregular lytic mass suggestive of a plasmacytoma. Fine needle aspiration confirmed this diagnosis. Positron Emission Tomography (PET)/CT imaging again showed the hypermetabolic destructive lesion in the left ninth rib, with a standard uptake value (SUV) of 13. Hypermetabolic nodes were scattered in the mediastinum, hilum and inguinal region, with a maximum SUV of 6, along with ground glass opacities in both lung bases. The plasmacytoma was treated with local radiotherapy and dexamethasone. PET/CT scan of chest, abdomen and pelvis 6 months after treatment revealed improvement in the plasmacytoma and lymphadenopathy, as well as resolution of the ground glass opacities. PET/CT scan a year after treatment revealed recurrence of the hypermetabolic lymph nodes in the hilar, mediastinal, axillary and inguinal regions, with an SUV of 6.8 (increased from the initial value of 6), without worsening of the primary plasmacytoma. An inguinal lymph node biopsy was performed for evaluation of the lymphadenopathy. The biopsy showed necrotizing granulomas. Cultures for myobacteria and fungi were negative and the diagnosis of sarcoidosis was confirmed. The patient received consolidation and maintenance chemotherapy which resulted in further regression of the thoracic plasmacytoma as well as sarcoidosis. Imaging done after two years showed that the plasmacytoma remained unchanged and sarcoidosis lymphadenopathy had completely resolved.
Plasmacytomas develop from the neoplastic proliferation of a single clone of plasma cells producing a monoclonal immunoglobulin. They generally occur as a single lesion and are estimated to account for 5% of all plasma cell disorders. Although a few reported cases of sarcoidosis in association with multiple myeloma have been described, there has only been one previously described case of coexisting plasmacytoma and sarcoidosis in case of a gastric plasmacytoma (2 ). Sarcoidosis may represent the host immune response to malignancy. This could explain the higher prevalence of sarcoidosis with cancers. This may also explain why the sarcoidosis resolved with treatment for the tumor in our patient. Sarcoidosis can create a major diagnostic dilemma in cancer patients presenting with hypermetabolic lymph nodes. Biopsy proven disease must therefore always be sought prior to treatment.
The first case of concomitant occurrence of sarcoidosis with a thoracic medullary plasmacytoma is reported. The possible association between sarcoidosis and cancer, and the implications of this association are discussed.
Toshita Kumar, No Financial Disclosure Information; No Product/Research Disclosure Information