Clinicopathological study of pulmonary extranodal nature killer/T-cell lymphoma, nasal type and literature review.

OBJECTIVES

Malignant tumors of the lung are predominantly derived from epithelial tissue, such as squamous cell carcinoma and adenocarcinoma, while pulmonary lymphatic and hematopoietic tumor is relatively rare. Extranodal NK/T-cell lymphoma (ENKTL), nasal type, originates in nasal and extra-nasal sites anatomically. This distinct non-Hodgkin lymphoma is endemic and is characterized by a highly aggressive clinical course and dismal survival outcome. Extra-nasal ENKTL, especially pulmonary ENKTL, is rare compared with nasal type ENKTL and has received relatively little attention. Therefore, this study was conducted to assess the clinicopathological features of pulmonary ENKTL and to promote awareness of this malignancy.

MATERIALS AND METHODS

All cases of ENKTL, nasal type diagnosed from January 2008 to June 2014 in our institution were collected, and those with pulmonary involvement were selected for further study. The eligible cases were analyzed retrospectively: medical recordings, imaging manifestations, pathological features, immunophenotypes, EBER1/2 hybridizations in situ and other related literatures were reviewed.

RESULTS AND CONCLUSIONS

A total of 1105 cases were diagnosed as ENKTL, nasal type, in this period, and 8 cases (7.2‰) had lung involvement. Seven cases had core biopsy, and for 1 case, a resected tissue specimen was available. The group was composed of 6 men and 2 women (gender ratio 3:1) with ages ranging from 19 to 44 (average age of 33.5) years. In this group, 2 cases were secondary and 5 cases were primary. The clinical symptoms and computed tomography (CT) manifestations were nonspecific. Histologically, the neoplasms presented angiocentric and angiodestructive growth patterns with different degrees of inflammatory response and necrosis. The neoplastic cell sizes were heterogeneous with spectra of small to large or mixed-composition types. For the immunophenotypes, all cases were positive for CD3ɛ and cytotoxic granule (granzyme B or TIA-1). The positive ratios of CD56 and CD30 were 6/8 and 4/5 respectively. All 8 cases showed positive in situ hybridization for Epstein-Barr virus-encoded small RNA (EBER). TCR-γ gene rearrangement was tested in 4 cases, and only 1 of these cases was monoclonal. Laboratory testing demonstrated that the whole blood was decreased while the average level of LDH was elevated. Six bone marrow biopsy specimens were negative and showed no neoplastic cells infiltration. For treatment, 4 individuals accepted chemotherapy and 1 patient underwent localized tumor resection surgery. The follow-up information was available for 6 patients, 1 of whom was alive and the other 5 cases survived shortly between 20 days and 4 months. ENKTL, nasal type of lung is very rare, and the diagnosis is challenging due to nonspecific clinical symptoms and imaging results. The diagnosis of pulmonary ENKTL should be based on comprehensive clinical, imaging, histopathological and molecular examination. More effective treatment strategies are required for this disease.