Objective:To investigate the clinicopathological features, diagnosis and differential diagnosis of primary central nervous system T-cell lymphomas (TPCNSL), and to analyze its biological behavior and prognosis.Methods:Three cases of TPCNSL were collected from September 2014 to September 2019 in the First Affiliated Hospital of Nanjing Medical University. They were evaluated by HE, immunohistochemistry (IHC) and molecular genetics, and the relevant literature was reviewed.Results:Among the 6 816 brain tumors, 97 were primary central nervous system lymphomas (PCNSL), including 3 TPCNSL. There were two male and one female patients, aged 60, 67, and 82 years. Clinically, they were presented with varying degrees of limb numbness and unstable gait. Microscopically, the tumor cells were distributed diffusely or around blood vessels. They showed significant atypia and brisk mitotic activity. By IHC, they were positive for LCA, CD3, CD43, TIA-1, and perforin. Two of three cases were positive for CD5 and granzyme B. T-cell receptor gene rearrangement was clonal. EBER in situ hybridization was negative. The patients were followed for 1 to 6 months; one patient received chemotherapy and died of recurrence 3 months after surgery. One patient died of recurrence 5 months after operation alone. One patient remained recurrence and metastasis free more than 4 months post surgery.Conclusions:PCNSL is uncommon, and most are B-cell lymphomas, while T-cell lymphomas are even rarer. As the latter may show atypical clinical manifestations, diverse histologic morphology and poor prognosis, early diagnosis and timely treatment are particularly important for patients to improve survival.

Objective:To study the clinicopathological characteristics, diagnosis and differential diagnosis of bronchiolar adenoma (BA).Methods:Fifteen cases of BA were collected from the First Affiliated Hospital of Nanjing Medical University, from January 2016 to October 2019. The clinical data, imaging examination, morphology, immunostaining and molecular changes were retrospectively analyzed.Results:There were 3 males, 12 females, most of the patients were female, mainly in middle-aged to elderly (51-77 years). Three had smoking history. The patients usually had no clinical symptoms. Imaging findings were ground-glass and/or lobulated nodules. Grossly, the tumors were gray-whitish, taupe solid or focally microcystic nodules with distinct boundary but no capsule. The maximum diameter was 0.4-2.5?cm (mean 1.0?cm). Histologically, there were glandular, papillary, or flat patterns that were composed of basal cells, mucous cells, ciliated cells and type Ⅱ pneumocytes, some of which showed basal cell proliferation and squamous cell metaplasia. However, there were some cases with few or even without mucous and/or ciliated cells. Immunostaining highlighted the continuous basal cell layer (positive for p63, p40 and cytokeratin 5/6), which was the most important diagnostic evidence. Genetic tests did not show mutation in BRAF or EGFR genes. All patients were followed up for 1-41 months, and they were without recurrence or metastasis.Conclusions:BA is a benign neoplasm that develops in the peripheral lung with good prognosis. Definite diagnosis is very crucial for surgical treatment, especially in frozen consultation. Immunohistochemistry will be helpful if necessary.