Nodular pulmonary amyloidosis and obvious ossification due to primary pulmonary MALT lymphoma with extensive plasmacytic differentiation: Report of a rare case and review of the literature

Abstract

Localized (primary) pulmonary amyloidosis associated with pulmonary low-grade B cell lymphoma is rarely occurred. Here we report an unusual case of nodular pulmonary amyloidosis and obvious ossification due to primary pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma with extensive plasmacytic differentiation in a 59-year-old man; moreover, two bronchial lymph nodes were involved histologically. The patient underwent a left lower lobectomy along with mediastinal lymphadenectomy. He received no adjuvant therapy and the postoperative course was uneventful within the 14 months follow-up period after his initial diagnosis.

Keywords: MALT lymphoma; Nodular pulmonary amyloidosis; ossification.

Figure 1

Chest computed tomography scan revealed an irregular solid mass with different density and marginal ossification at the left lower lobe of lung.

Figure 2

A. The tumor was solid and firm, confined within the left lower lung, the colour of cut surface was gray and grayish green. B. The cut surface of two bronchial lymph nodes was gray in color.

Figure 3

Histologic findings. A. Extensive eosinophilic amorphous material deposition. B. Obvious metaplastic ossification accompanied by a granulomatous reaction. C. Focal aggregates of lymphocytes with extensive plasmacytic differentiation. D. Reactive lymphoid follicles with germinal centers. E. Lymphatic tracking. F. Pleural infiltration by neoplastic lymphocytes. G. The lymphoid infiltrate was intense and lacked a gradient from the center of the nodular lesion to its periphery. H. Lymphoepithelial lesion was found in a part of the bronchiolar epithelium. I. Extensive amyloid deposition, with neoplastic lymphoplasmacytic aggregated at the periphery was observed in bronchial lymph nodes. (A, B, D, E, G and I: × 100; C, F and H: × 400).

Figure 4

Histochemical and immunohistochemical findings. The Lymphoma cells were positive for CD20 (A), CD79a (B), bcl-2 (C), CD138 (D), lambda light chain (E), CD43 (F), and negative for CD3 (G) and kappa light chain (H); Extensive amyloid protein deposition was confirmed by Congo red staining (I). (A-F, H: × 400; G and I: × 200).