A Case of Primary Plasmacytoma of Lymph Nodes
A 56-year-old man was admitted to the otorhinolaryngology department, complaining of multiple palpable masses in the right cervical and submandibular areas, which slowly progressed in size during the past 8 years. The patient had neither any remarkable past medical history, nor a family history relevant to such a complaint. On physical examination, no palpable lymph nodes or masses in any other area of the body were noted. Initial laboratory values revealed mild anemia (Hb 11.6 g/dL), but normal leukocyte and platelet counts. Blood urea nitrogen (BUN), creatinine, calcium, inorganic phosphate, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and serum electrolyte levels were found to be normal. Serum albumin was 3.3 g/dL, and total protein was 8.9 g/dL. There were no abnormalities on the routine urine analysis. Neck and paranasal sinus computed tomography (CT) scans were conducted as part of an evaluation for surgical resection. Numerous enlarged lymph nodes were found to be conglomerated in the right submental and submandibular areas (level II, III, IV, V). The largest of these measured about 6.7×4.7 cm, and the right internal jugular vein was appeared to have been severely compressed by multiple enlarged lymph nodes. The tonsil, salivary gland, paranasal sinus, and nasal cavity yielded no abnormal findings (). The patient underwent surgery for the removal of the masses, but some small remnant masses persisted. Upon the gross examination of the removed lymph nodes, multiple grayish-white masses were seen, ranging from 2.5×1.8×1.5 cm to 6.5×5×4.5 cm in dimensions. Upon sectioning of the lymph nodes, the cut surfaces were grayish-white with focal hemorrhaging (). Histologically, the masses were composed of dense and diffuse infiltrations of atypical plasma cells, with a few residual atrophic lymphoid follicles. These secreted immunoglobulin (Lambda positive) aggregates with extensive amyloid deposits (Congo Red positive, Lambda positive/Kappa negative) in both the stroma and blood vessel walls (). After the operation, the patient was transferred to the hemato-oncologic department, for further evaluation and treatment. A full work-up was conducted in order to ascertain whether there was any other evidence of plasma cell dyscrasia. Serum and urine protein electrophoresis (PEP) and immunoelectrophoresis (IEP) were also conducted. Serum PEP revealed an M-spike in the gamma region, and serum IEP revealed abnormal arcs against anti-IgG and anti-Lambda antisera (), but urine PEP was not performed due to the small amount of available protein, and urine IEP revealed no abnormal arcs. The β2-microglobulin level was found to be normal (1.6 mg/L), and no osteolytic lesions were noted on the skeletal evaluation, which included a skull series. Rouleux formations were seen on the peripheral blood smear. However, bone marrow aspiration and biopsy from the iliac crest revealed trilineage elements of normal hematopoiesis, as well as no evidence of plasma cell dyscrasia. Accordingly, the patient was diagnosed with primary lymph node plasmacytoma, and was treated via radiotherapy (total dose of 50 Gy in 25 fractions). The residual mass is about 1×2 cm sized, so we are planning to monitor the patient with PET CT scans, as well as a neck CT, in order to assess the viability of the remaining mass.