Hemotoxylin and eosin staining of the biopsy tissue revealed subepithelial nests of overcrowded small cells showing high nuclear cytoplasmic ratio, hyperchromatic nuclei with speckled chromatin, and scanty eosinophilic cytoplasm. These cells were separated by fibrous tissue and areas of hemorrhage. On immunohistochemical staining, cells were strongly positive for leukocyte common antigen and CD20, and negative for neuron specific enolase, CK-7, and CD3. These findings were suggestive of low-grade non-Hodgkin lymphoma of B-lineage. The patient refused to undergo further investigation and treatment.
Mucosa-associated lymphoid tissue located under respiratory tract epithelia is known as bronchus-associated lymphoid tissue (BALT). BALT lymphoma (also known as pulmonary mucosa-associated lymphoid tissue lymphoma) is a relatively rare, low-grade, and slowly growing non-Hodgkin lymphoma. Mucosa-associated lymphoid tissue lymphoma (MALT lymphoma) arises from extranodal tissue. Stomach is the commonest site of involvement and other common organs are lung, thyroid, salivary glands, and intestine. No infective agents have been identified for the nongastrointestinal MALT lymphoma. BALT lymphomas are probably acquired secondary to antigenic stimuli or autoimmune disease with subsequent progression to lymphoma.
BALT lymphoma shows a peak incidence in the sixth and seventh decade of life. BALT lymphoma involving glottic or subglottic region is relatively rare.1 Lung lesions of BALT lymphoma are usually peripheral and may be mass-like consolidation (87%), solitary, or multiple nodules (75%).2 Occasionally, it can present as localized endobronchial lesion. However, bronchoscopically there may be no abnormality or mucosal inflammation or stenosis.3 The diagnostic yield of bronchoscopy is high in the presence of endobronchial lesions. In a series of 20 patients with BALT lymphoma, bronchoscopic diagnosis was possible in only 6 patients; the rest required thoracotomy for the diagnosis.4
A majority of patients with BALT have no respiratory symptoms and usually are found to have an abnormal chest imaging study at presentation. Rarely, they may present with cough (most common symptom), hemoptysis, and dyspnea.
The histopathologically BALT lymphoma are characterized by infiltration of small lymphocytes invading the epithelial structures, forming the lymphoepithelial lesion. Immunohistologic examination will confirm that the neoplastic cells have the characteristic monoclonal B-cell origin.
These lymphomas show indolent growth, remain localized for a long time, and respond well to local therapy. BALT lymphoma can be treated by laser resection, chemotherapy, radiotherapy, or combined chemoradiotherapy. The present case is a unique case of BALT lymphoma simultaneously involving subglottic and endobronchial mucosa.
Sajal De MD, FCCP
Mahatma Gandhi Institute of Medical Sciences Sevagram, Maharashtra, India
The author wishes to thank Dr Ritu Singhal, Department of Pathology, Jawaharlal Nehru Cancer Hospital, Bhopal, for her help in histopathological diagnosis.
1. Steffen A, Jafari C, Merz H, et al. Subglottic MALT lymphoma of the larynx-more attention to the glottis In Vivo.. 2007;21:695–698
2. King LJ, Padley SPG, Watherspoon AC, et al. Pulmonary MALT lymphoma: imaging findings in 24 cases Eur Radiol.. 2000;10:1932–1938
3. Cadranel J, Wislez M, Antoine M. Primary pulmonary lymphoma Eur Respir J.. 2002;20:750–762
4. Kim JH, Lee SH, Park J, et al. Primary Pulmonary Non-Hodgkin's Lymphoma Jpn J Clin Oncol.. 2004;34:510–514
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