Diagnostic red flags: steroid‐treated malignant CNS lymphoma mimicking autoimmune inflammatory demyelination

The presence of inflammation and demyelination in a central nervous system (CNS) biopsy points towards a limited, yet heterogeneous group of pathologies, of which multiple sclerosis (MS) represents one of the principal considerations. Inflammatory demyelination has also been reported in patients with clinically suspected primary central nervous system lymphoma (PCNSL), especially when steroids had been administered prior to biopsy acquisition. The histopathological changes induced by corticosteroid treatment can range from mild reduction to complete disappearance of lymphoma cells. It has been proposed that in the absence of neoplastic B cells, these biopsies are indistinguishable from MS, yet despite the clinical relevance, no histological studies have specifically compared the two entities. In this work, we analyzed CNS biopsies from eight patients with inflammatory demyelination in whom PCNSL was later histologically confirmed, and compared them with nine well defined early active multiple sclerosis lesions. In the patients with steroid‐treated PCNSL (ST‐PCNSL) the interval between first and second biopsy ranged from 3 to 32 weeks; all of the patients had received corticosteroids before the first, but not the second biopsy. ST‐PCNSL patients were older than MS patients (mean age: ST‐PCNSL: 62 ± 4 years, MS: 30 ± 2 years), and histological analysis revealed numerous apoptoses, patchy and incomplete rather than confluent and complete demyelination and a fuzzy lesion edge. The loss of Luxol fast blue histochemistry was more profound than that of myelin proteins in immunohistochemistry, and T cell infiltration in ST‐PCNSL exceeded that in MS by around fivefold (P = 0.005). Our data indicate that in the presence of extensive inflammation and incomplete, inhomogeneous demyelination, the neuropathologist should refrain from primarily considering autoimmune inflammatory demyelination and, even in the absence of lymphoma cells, instigate close clinical follow‐up of the patient to detect recurrent lymphoma.     

人表皮细胞与角膜上皮细胞蛋白质组的差异表达初步研究

目的：应用蛋白质组技术比较人表皮细胞与角膜上皮细胞之间的蛋白质表达差异。方法：实验于2005-11，2006-10在中山大学中山眼科中心国家眼科学重点实验室完成。分别培养人表皮细胞与角膜上皮细胞，裂解原代细胞抽提总蛋白，精确定量后进行双向电泳，扫描电泳凝胶获得二维总蛋白图谱。图谱使用软件辅助比较分析，找出差异表达点，从凝胶中抠取差异点，胶内酶解后用基质辅助激光解吸附，电离飞行时间串级质谱法鉴定差异蛋白。结果：人表皮细胞与角膜上皮细胞蛋白质凝胶分析获得600余个清晰的蛋白质斑点，在比较分析出的26个差异点中初步鉴定出4个差异表达蛋白，分别是细胞内氯离子通道1、Psodasin、乳酸脱氢酶B和丝氨酸蛋白酶抑制因子。结论：人表皮细胞与角膜上皮细胞在蛋白质表达上有较高的相似性以及较好的可比性，为探索表皮细胞横向分化成角膜上皮细胞的分子机制做出了有益的尝试，并提供了具有一定可操作性的实验方法。     

DIGITAL ISCHAEMIA: AN UNUSUAL PRESENTATION OF DYSBARISM

SUMMARY Dysbaric symptoms following ascent from a scuba dive are due to symptomatic nitrogen or air emboli with clear patterns of associated injury. This case report highlights an unusual presentation of dysbaric injury treated successfully with a prostacyclin analogue.     

Primary Extracranial Meningiomas: An Analysis of 146 Cases

Primary extracranial meningiomas are rare neoplasms, frequently misdiagnosed, resulting in inappropriate clinical management. To date, a large clinicopathologic study has not been reported. One hundred and forty-six cases diagnosed between 1970 and 1999 were retrieved from the files of the Armed Forces Institute of Pathology. Histologic features were reviewed, immunohistochemistry analysis was performed (n = 85), and patient follow-up was obtained (n = 110). The patients included 74 (50.7%) females and 72 (49.3%) males. Tumors of the skin were much more common in males than females (1.7:1). There was an overall mean age at presentation of 42.4 years, with a range of 0.3–88 years. The overall mean age at presentation was significantly younger for skin primaries (36.2 years) than for ear (50.1 years) and nasal cavity (47.1 years) primaries. Symptoms were in general non-specific and reflected the anatomic site of involvement, affecting the following areas in order of frequency: scalp skin (40.4%), ear and temporal bone (26%), and sinonasal tract (24%). The tumors ranged in size from 0.5 up to 8 cm, with a mean size of 2.3 cm. Histologically, the majority of tumors were meningothelial (77.4%), followed by atypical (7.5%), psammomatous (4.1%) and anaplastic (2.7%). Psammoma bodies were present in 45 tumors (30.8%), and bone invasion in 31 (21.2%) of tumors. The vast majority were WHO Grade I tumors (87.7%), followed by Grade II (9.6%) and Grade III (2.7%) tumors. Immunohistochemically, the tumor cells labeled for EMA (76%; 61/80), S-100 protein (19%; 15/78), CK 7 (22%; 12/55), and while there was ki-67 labeling in 27% (21/78), <3% of cells were positive. The differential diagnosis included a number of mesenchymal and epithelial tumors (paraganglioma, schwannoma, carcinoma, melanoma, neuroendocrine adenoma of the middle ear), depending on the anatomic site of involvement. Treatment and follow-up was available in 110 patients: Biopsy, local excision, or wide excision was employed. Follow-up time ranged from 1 month to 32 years, with an average of 14.5 years. Recurrences were noted in 26 (23.6%) patients, who were further managed by additional surgery. At last follow-up, recurrent disease was persistent in 15 patients (mean, 7.7 years): 13 patients were dead (died with disease) and two were alive; the remaining patients were disease free (alive 60, mean 19.0 years, dead 35, mean 9.6 years). There is no statistically significant difference in 5-year survival rates by site: ear and temporal bone: 83.3%; nasal cavity: 81.8%; scalp skin: 78.5%; other sites: 65.5% (P = 0.155). Meningiomas can present in a wide variety of sites, especially within the head and neck region. They behave as slow-growing neoplasms with a good prognosis, with longest survival associated with younger age, and complete resection. Awareness of this diagnosis in an unexpected location will help to avoid potential difficulties associated with the diagnosis and management of these tumors.