[Early onset Epstein-Barr virus-negative diffuse large B cell lymphoma after bilateral lung transplantation: a case report]

Lymphoma after solid organ transplantation is one of the manifestations of post-transplant lymphoproliferative disorders(PTLD). Here we reported a 39-year-old male patient presented with intermittent fever, markedly elevated level of peripheral blood lymphocytes and lactate dehydrogenase(LDH), rapid decrease in hemoglobin and platelet count ten months after bilateral lung transplantation. After systematic evaluation, the patient excluded infectious diseases. Positron emission tomography-computed tomography (PET/CT) revealed diffuse increasing of standard uptake value in bones throughout the body. The bone marrow aspiration, flow cytometric analysis and histopathology confirmed the diagnosis of diffuse large B-cell lymphoma (DLBCL) with negative Epstein-Barr virus-encoded small RNA (EBER) hybridization in situ. Meanwhile, complicated hemophagocytic lymphohistiocytosis was also diagnosed in the patient based on hypertriglyceridemia, abnormally elevated level of serum ferritin and solvable CD25 (sCD25). Treatment regimen included reduction of immunosuppression, anti-CD20 antibody (CD20⁺ B cell inhibitor, rituximab) and etoposide. Repeated PET/CT and bone marrow biopsy showed complete remission of lymphoma after 4 months of therapy.

[Clinicopathological features and prognosis of primary mediastinal large B-cell lymphoma: a series of sixty cases]

Objective: To investigate the clinicopathological features and prognostic factors of primary mediastinal large B-cell lymphoma (PMBL). Methods: The clinical data of 60 patients with PMBL including 44 biopsy cases and 16 consultation cases from September 2000 to November 2019 in the Department of Pathology, China-Japan Friendship Hospital (14 cases) and Peking Union Medical College Hospital (46 cases) were enrolled. Pathologic features, immunophenotype, immunoglobulin (Ig) gene rearrangement and microRNA expression profile were retrospectively studied. Results: Of the 60 patients, 23 were males and 37 were females, age ranged from 15 to 64 years (median 28 years). Immunohistochemical staining showed that the tumor cells were positive for pan-B cell antigens, CD30 (77.4%, 24/31), CD23 (73.1%, 19/26), MUM1 (45.8%, 11/24), Ki-67 index ≥70 % (90.6%, 29/32). EBER in situ hybridization was analyzed in 21 PMBL, only one case (4.8%) was positive. Ig gene rearrangement was performed in 20 cases, and seven were positive (35.0%). MicroRNA gene expression profiles were analyzed in seven cases of PMBL and nine cases of diffuse large B-cell lymphoma, and there were 33 microRNAs with significant difference (P<0.05). Univariate analysis indicated that the poor prognostic factors included serum lactate dehydrogenase (LDH) level,International Prognostic Index (IPI) score ≥3, stages Ⅲ-Ⅳ, chemotherapy not combined with rituximab and MUM1 positivity (P<0.05). Multivariate analysis showed that the treatment combined with rituximab was independently related to prognosis (P<0.05). Conclusions: PMBL is different from diffuse large B-cell lymphoma in clinicopathologic features, immunophenotypic presentation and molecular features. The prognostic factors, molecular genetics and immunological characteristics reveal that this study has enriched our understanding of the biology of PMBL, thus providing evidence and strategies for treatment.

[Clinicopathological features of bronchiolar adenoma versus mixed squamous cell and glandular papilloma: a comparative analysis]

Objective: To observe the clinicopathological features of bronchiolar adenoma (BA) and mixed squamous cell and glandular papilloma (MSGP). The relationship between them was also analyzed. Methods: Clinical data of eight patients with BA and four patients with MSGP diagnosed in China-Japan Friendship Hospital were collected from January 2018 to January 2020. Hematoxylin-eosin staining and immunohistochemical staining (EnVision method) were used to compare their histopathological characteristics. The hotspots regions of cancer-associated driver genes in lung cancer, using real-time quantitative PCR, were detected in all the cases and the literatures were reviewed. Results: The clinical and imaging manifestations of BA and MSGP were analogous. Histologically they had a two-layer structure including bronchial or bronchiolar-type epithelium and a continuous layer of basal cells,similar to bronchial/bronchiole mucosae. P16 protein was highly expressed in 7/8 of BA and 1/4 of MSGP. Mutations of cancer-associated genes were detected in 4/8 of BA, but none in MSGP. Conclusions: BA and MSGP, derived from different parts of the respiratory tract in the lungs, are rare and benign. Their morphological features overlapped with each other, and some cases are accompanied by genetic changes. It is necessary to pay attention to the differential diagnosis between them and lung adenocarcinoma, especially during the intraoperative diagnosis; and be alert to the potentially malignant components in the tumor or combined cancers.

[Clinicopathological analysis of clear cell renal cell carcinoma with hemangioblastoma component]

Objective: To investigate the clinicopathological features, differential diagnosis and molecular characteristics of clear cell renal cell carcinoma (ccRCC) with hemangioblastoma component (ccRCC-HBc). Methods: Two ccRCC-HBc cases diagnosed at Fujian Provincial Hospital in September 2015 and March 2016, respectively, were included. Their morphological, immunohistochemical and molecular features were analyzed, including fluorescence in situ hybridization (FISH) detection of TFE3, TFEB and VHL genes. Related literature was reviewed to reveal the characteristics of this tumor. Results: The two cases occurred in 2 women, aged 33 and 66 years, respectively. The maximum diameters of the tumors were 4.0 cm and 8.5 cm, respectively. Histologically, the ccRCC component, representing approximate 10%-20% of the neoplasm, while the tumor cells arranged in flaky, nested, and solid distribution. The tumor cells had conspicuous nucleoli, with rich thin-wall capillary network in the stroma. The hemangioblastoma-like component, representing approximate 60%-70% of the neoplasm, showed a rich capillary network of single-layered flat endothelial cells enclosing stromal cells. The latter cell type showed a pale or eosinophilic cytoplasm exhibiting occasional lipid droplets. Rare cell nuclei appeared enlarged, pleomorphic, or bizarre. The two components were intermingled with each other. Immunohistochemically, the tumor cells were positive for PAX8, CKpan, EMA, vimentin, CD10, RCC, CAⅨ, and P504s in ccRCC area; in another area, the tumor cells were positive for α-inhibin, CD34 and vimentin, while CD10 were weakly positive. Neither TFE3 or TFEB gene split signal was detected in the 2 cases (0/2), nor was VHL gene mutation in case 2 (0/1). Conclusion: ccRCC-HBc is an extremely rare entity of ccRCC. The diagnosis is mainly based on clinical and pathological characteristics, as well as immunohistochemistry. Molecular pathology is helpful for its differential diagnosis. The primary approach of treating ccRCC-HBc is complete surgical excision and chemotherapy. The targeted treatment is helpful if possible.

[Primary extraskeletal osteosarcoma: a clinicopathological study of ten cases]

Objective: To investigate the clinicopathologic features, differential diagnosis, immunohistochemical profiles and molecular characteristics of primary extraskeletal osteosarcoma (ESOS). Methods: Ten cases of ESOS diagnosed and treated in Fujian Provincial Hospital, Fuzhou, China from January 2003 to January 2019 were collected and subjected to immunohistochemical staining and molecular analyses. The patients were followed up by telephone interview. Relative literature was also reviewed to assess the characteristics of this tumor. Results: The ten cases occurred in 3 women and 7 men, aged from 36 to 85 years (median, 60 years). The sizes of these tumors ranged from 5.5 to 17.5 cm (median, 11.0 cm). Histologically, at low magnification, the tumors were nodular, leafy and lobulated. They were composed of spindle cells, neoplastic osteoid cells, and cartilage tissues, with unequally-proportional mixture of these components. The three components intermingled with each other. Immunohistochemistry profiling showed that the tumor cells were positive for SATB2 (9/9), while α-SMA (4/10) and EMA (1/10) stains were focally positive. Ki-67 proliferation index was 10%‒50%. Desmin, CD68, S-100 protein, SOX10, HMB45, CD117, DOG1, CD34, CKpan, GATA3 and PAX8 stains were negative. MDM2/CDK4 gene amplification signals were not detected in the 6 cases (0/6), which were subjected to the FISH. The SSX18 break-apart signal and the C-KIT and PDGFR-α mutations were not detected (0/5 and 0/3, respectively). Conclusions: Primary ESOS is an extra-osseous osteogenic tumor. The diagnosis is mainly dependent on clinical, radiological and pathological characteristics. Immunohistochemistry and molecular profiling are helpful for making the correct diagnosis.

[Clinicopathological characteristics of pulmonary artery intimal sarcoma]

Objective: To describe the clinicopathological features of pulmonary artery intimal sarcoma (PAIS), and to understand its molecular alterations. Methods: Sixty cases of pulmonary artery endarterectomy performed at the China-Japan Friendship Hospital, Beijing, China from January 2017 to January 2020 were reviewed. Clinical data of 5 patients with pulmonary artery intimal sarcoma were collected. Hematoxylin-eosin staining, immunohistochemistry staining and fluorescence in situ hybridization (FISH) were performed to evaluate the pathological features. RNA sequencing was conducted to assess the fusion gene changes in PAIS. Results: The detection rate of PAIS was 8.3% (5/60), with the median age of 49 years and a female predominance. Their clinical manifestations were non-specific. Histopathological examination showed that the tumors were composed of malignant spindle or epithelioid cells, with various degrees of atypia. Focal heterologous osteosarcomatous or leiomyosarcomatous differentiation was noted. The tumor cells could express PDGFRA, CDK4 and MDM2 with co-amplification of MDM2, CDK4 and EGFR genes. RNA sequencing detected multiple in-frame fusions in the tumors. Conclusions: PAIS is a rare, highly heterogeneous, and poorly-or un-differentiated sarcoma accompanied by complex changes of multiple genes.It has no known effective treatments, and thus has a poor prognosis.

[Clinicopathological and genetic characteristics of lung cancer in the lungs of explanted from lung transplant recipients]

Objective: To describe the clinicopathological features of the lung cancers in the lungs explanted from lung transplant recipients, and to understand the molecular alterations of these cancers. Methods: The patients who underwent lung transplantation in China-Japan Friendship Hospital from March 2017 to December 2018 were reviewed. Clinical data of the patients with lung cancer associated with end-stage interstitial lung diseases (ILD) were collected. Hematoxylin-eosin staining and immunohistochemistry were performed to evaluate the pathological feature. Real-time quantitative PCR was performed to analyze the hotspots and targeted regions of 9 cancer-associated genes. Results: Among the 154 identified patients, 10 met the inclusion criteria and were included. The detection rate of lung cancer in the lung transplantation patients was 6.5%(10/154). All of the included 10 patients were male, with an average age of 59 years. They all had a history of heavy smoking. Three cases had a lung cancer diagnosed before operation, while the other 7 cases were concealed in the specimen of end-stage ILD. All of lung cancers were non-small-cell carcinoma, including 8 cases of adenocarcinoma and 2 cases of squamous cell carcinoma. The proportion of mucinous adenocarcinoma components was 3/10. The mutations in KRAS gene exon 2 were detected in two patients with mucous adenocarcinoma, while no alterations in NRAS, EGFR, ALK, ROS1, BRAF, HER2, PI3KCA and RET were detected in the remaining patients. Conclusions: Lung cancers are difficult to detect in patients with end-stage ILD. They are mainly adenocarcinomas and associated with a higher frequency of mutations in KRAS gene. These cancers have limited treatment options and a poor prognosis.

[Clinical pathologic characteristics of extranodal follicular dendritic cell sarcoma]

Objective: To investigate the clinical pathologic characteristics of extranodal follicular dendritic cell sarcoma (FDCS). Methods: We collected 7 cases of extranodal FDCS, HE staining, immunohistochemical study were performed. The V600E mutation of BRAF in 7 cases were detected by real-time PCR and EBER in situ hybridization was performed on 4 cases. Results: Among the 7 cases of FDCS, 5 cases were male and 2 cases were female, the median age was 55 years old, including 4 cases of low-grade FDCS and 3 cases of high-grade FDCS. The tumor location of 2 cases was in mediastinum, the tumor locations of others were in nasopharynx, kidney, lung, rectum and liver, respectively. The results of immunohistochemistry showed that, the tumor cells were diffusely or focally positive for CD21, CD23, CD35, D2-40, EGFR and CXCL13, but negative for S-100, CD68, HMB45, SMA, Desmin, CD117, Dog-1, CD34, CD30, EMA and CK.Five cases were positive for PD-L1 and the its expression in high-grade FDCS were higher than that in low-grade FDCS.Two cases of low-grade FDCS were positive for BRAF V600E, but the BRAF V600E mutation weren't detected in all of 7 cases. The result of EBER in-situ hybridization showed that only the nasopharynx FDCS was positive.The follow-up information of 5 patients were available (7~43 months), 4 patients died and 1 still alive with rectum metastasis. Conclusions: FDCS is a rare malignant disease with relapse and metastatic tendency. The combined applications of the first-line antibodies including CD21, CD23, CD35 and second-line antibodies including D2-40, CXCL13, EGFR are helpful for its diagnosis and differential diagnosis. The high expression of PD-L1 implicates the potential benefit of FDCS patients acquired from immunotherapy.

[Clinical characteristics of intravascular large B cell lymphoma: a single-center retrospective study]

目的

提高对血管内大B细胞淋巴瘤（IVLBCL）的认识。

方法

回顾性分析北京协和医院自2010年1月至2016年6月收治的12例IVLBCL患者的临床资料。

结果

①12例患者中，男6例，女6例，中位年龄为58.5（32~76）岁。临床表现：发热最为常见（10/12），其次为呼吸系统症状（咳嗽、呼吸困难、胸腔积液等，6/12）、噬血细胞综合征（6/12）、神经系统症状（1/12）；所有患者均有LDH升高（367~1 700 U/L）、铁蛋白升高（805~1 527 µg/L）、结外器官受累（肺6例，骨髓3例，脑2例，软脑膜、肾上腺、副鼻窦、胆囊、甲状腺各1例）。②组织病理特征：光镜下可见分布于小血管内的单个或小簇状淋巴瘤细胞，毛细血管或血窦结构得以保留，免疫组化显示CD20、CD79a等B淋巴细胞标志阳性。③疗效及预后：11例患者接受CHOP或R-CHOP方案化疗，其总反应率为90.1%，完全缓解率为66.7%。患者平均随访20（1~40）个月，中位生存期及中位无进展生存期尚未达到。单因素Cox回归分析未能发现年龄、分期、IPI等临床参数与预后相关。

结论

IVLBCL临床罕见，出现肺部受累比例高，肺活检有较高阳性率；R-CHOP方案目前仍是最主要的治疗方案。

[Clinical and immunohistopathologic study of phosphaturic mesenchymal tumor]

Objective: To study the clinicopathological characteristics and immunohistochemical phenotype of phosphaturic mesenchymal tumor (PMT) . Methods: The clinicopathological data and immunohistochemical profiles were obtained retrospectively from 206 patients diagnosed with PMT at Peking Union Medical College Hospital (PUMCH) during July 2008 to September 2017, with a review of literature. Results: The mean age of PMT patients was 42 years (range 13 to 70 years), with a male to female ratio of 1.1∶1.0. All patients presented with different degree of bone pain, muscle weakness, shorten of stature, thoracic deformity and pathological fractures, with hypophosphatemia and high serum ALP. Phosphatemia returned to normal within 1 week after operation in all cases underwent complete tumor resection. The duration of osteomalacia before resection (documented in 197 cases) ranged from 20 days to 40 years (average 5.7 years). The average blood phosphorus concentration raised from 0.49 mmol/L to 0.92 mmol/L before and after tumor resection (P<0.01), with 147 cases (84.0%, 147/175) returned to normal range within 2 weeks. The rate or blood phosphorus concentration recovery in 15 days after operation was 79.6% in average, displayed significant differences between patients with complete resection and those with partial resection (85.4% vs. 21.1%, P<0.01). PMT lesions mainly involved lower extremities (55.8%), followed by head and neck (29.1%). In immunohistochemical study, all cases were positive for vimentin (100.0%), while most cases were positive for NSE (96.3%), CD56 (94.2%), FGF23(88.4%), CD68 (88.3%), D2-40 (70.9%), CD34 (23.1%), SMA (55.5%), bcl-2 (59.8%) and CD99 (47.1%). The Ki-67 positive index of tumor varied from less than 2% (51.4%), 3% to 10% (41.3%) to >10% (7.2%). Conclusions: PMT mainly occurs in lower limbs or head and neck, with unique clinical characteristics and blood biochemical indexes. The tumor expresses a variety of immunohistochemical markers, indicating the potential of multi-directional differentiation. Clinical profile, blood biochemistry testing and immunohistochemical phenotype is helpful for diagnosis of PMT.

[Clinical and pathological characteristics of Erdheim-Chester disease involving the lungs]

Objective: To explore the clinical manifestations, pathological features, differential diagnosis and gene mutation status in patients with pulmonary involvement of Erdheim-Chester disease (ECD). Methods: The clinical data of 4 cases of Erdheim-Chester disease admitted to Peking Union Medical College Hospital from October 2014 to August 2016 were examined for imaging, microscopic and immunohistochemitry findings, and BRAFV600E mutation. The related literatures were reviewed. Results: Among the 4 cases, there were 3 males and 1 female, aging from 7 to 47 years, and the average age was 34.5 years. They complained of chest tightness, shortness of breath and bone pain. They all had multiple bone lesions, involving the long bones, skulls and vertebrae, and imaging showed increased bone uptake and bone sclerosis. CT scan showed pleural thickening or pleural effusion(4/4), widened lobular septa(3/4), bronchial vascular bundle thickening(3/4), multiple patchy ground glass and solid shadows(4/4), and cystic shadows(1/4). Multiple bone lesions were the main extrapulmonary manifestations. All the cases had multiple bone lesions, involving the long bones, skulls and vertebrae, and showed increased bone uptake and bone sclerosis. Surgical biopsy of the thoracic tissue was performed in all 4 cases (pleural in 1 case, lung in 2, anterior mediastinal mass in 1). Microscopically, the lesion was composed of spindle-shaped fibroblasts and foamy histiocytes enmeshed in reactive fibrous tissue. Lymphocytes and plasma cells were also found. Immunohistochemically, all the histiocytes were positive for CD(68), and none of them expressed CD1a. All cases were detected by real-time quantitative PCR for BRAFV600E gene mutation. Conclusions: The pulmonary involvement of Erdheim-Chester disease is rare, with clinical manifestations of chest tightness, shortness of breath, and some have no obvious respiratory symptoms. Pulmonary involvement in Erdheim-Chester disease has important manifestations, in which foam-like tissue cells with diffuse distribution along the lymphatic enmeshed in reactive fibrous tissue. It should be differentiated from diffuse interstitial lung diseases and metastatic tumors. The clinical features are often manifested as pleural thickening and pleural effusion, with multiple bone sclerosis lesions.BRAFV600E mutation detection is helpful for the diagnosis.

[The 453rd case: diarrhea, weight loss and diabetes mellitus]

Chronic diarrhea is a common complaint in gastroentology department, which is classified into a variety of types. While as eosinophilic gastroenteritis is a rare cause. A 50-year-old male patient was admitted with a 2-year history of diarrhea worsened for 10 months. Fasting could alleviate the diarrhea. Laboratory findings demonstrated anemia, low vitamins and minerals, fat malabsorption and abnormal D-xylose absorption test, delayed gastric emptying. According to the endoscopic biopsy of gastrointestinal mucosa, the diagnosis of eosinophilic gastroenteritis was made. Diabetic neuropathy may aggravate the symptom. The diarrhea resolved after the administration of steroids.

[Associations of sigmoid colon mucosal mast cells with bowel symptoms and psychological status in patients with irritable bowel syndrome with diarrhea]

OBJECTIVE

To investigate the bowel symptoms and psychological status of patients with irritable bowel syndrome (IBS) with diarrhea (IBS-D), and to verify whether sigmoid colon mucosal mast cells (MCs) and their activation have effect on the symptoms and psychological status of IBS-D patients.

METHODS

Patients meeting Rome Ⅲ diagnostic and subtyping criteria of IBS-D who visited the outpatient clinic of gastroenterology of Peking Union Medical College Hospital were consecutively enrolled between July 2009 and June 2012. IBS symptoms questionnaire was completed using face-to-face interview, and Hamilton Anxiety Scale (HAMA)/ Hamilton Depression Scale (HAMD) were administrated to evaluate psychological status, both by well-trained investigators. Mast cell tryptase monoclonal antibody was used for immunohistochemical staining to detect MCs and degranulated MCs in mucosal biopsy of sigmoid colon. MCs and degranulated MCs were blindly counted by a senior pathologist, and presented as number of cells in high power field (HPF) and percentage of activated MCs. Correlation analysis was performed using Spearman rank correlation analysis.

RESULTS

Ninety-seven patients with IBS-D were enrolled in this study, with mean age of (44±11) years. 70.10%(68 cases) of the IBS-D patients had comorbid anxiety and/or depression. The median total numbers of MCs, activated MCs, and percentage of activated MCs in sigmoid mucosa were 11.60 (7.09)/HPF, 2.00 (1.40) /HPF, and 17.50% (10.90%), respectively. Patients having abdominal pain/discomfort before bowel movement "every day with intermediate to high severity" had significantly larger numbers of total MCs in sigmoid colon compared with those with pain or discomfort "not every day and mild" [13.80(4.85)vs 7.60(5.90)/HPF, P=0.019]; the patient having "frequent" urge to have a bowel movement and mushy stools showed significantly higher percentage of activated MCs in sigmoid colon mucosa compared to those having the symptoms "some of the time" [18.75%(9.12%) vs 14.50%(13.14%), P=0.031; 21.33%(7.43%)vs 11.51%(10.65%)vs 18.42%(8.61%), P=0.030]. There was a positive correlation between the bowel movement during IBS-D onset and the percentage of activated MCs (r=0.221, P=0.030). There were no statistically significant differences in the total number of MCs and percentage of activated MCs between the patients with anxiety/depression and those without anxiety/depression (P=0.255, P=0.315). Scores of HAMA and HAMD were found not correlated with either total MCs number or percentage of activated MCs in sigmoid colon mucosa(all P>0.05).

CONCLUSIONS

The majority of IBS-D patients had comorbid anxiety and/or depression. The total number and activation status of MCs in sigmoid colon mucosa might be related with some intestinal symptoms in IBS-D patients. Psychological disorders might influence the pathogenesis and regression of IBS-D through brain-gut axis other than MCs in sigmoid colon mucosa.

[Clinical and radiologic characteristics of craniomaxillofacial primary tumor induced osteomalacia: a retrospective analysis]

OBJECTIVE

To investigate the diagnosis strategy, radiology and clinical pathology feature of craniomaxillofacial primary tumor induced osteomalacia.

METHODS

Twelve cases of craniomaxillofacial primary tumor induced osteomalacia were reviewed, including 5 male and 7 female with a age range from 16 to 69 years. The clinical characteristics, radiology examinations and pathological features were analyzed.

RESULTS

The craniomaxillofacial primary tumor induced osteomalacia occurred in different ages, with 2 to 30 years of medical history. Seven of the twelve cases were octreotide scintigraphy positive, nine of the twelve cases invaded bone, exhibiting destruction of the adjacent cortex, ten of the twelve showed gingival lesions of local thickening or epulis. The tumor arises from mesenchymal tissue, infiltrating local gingiva and bone trabecular with spindle like fibroblasts and dental epithelial rests.

CONCLUSIONS

The concealed nature of the tumor induced osteomalacia requires multiple methods to locate the primary tumor and the tumors located in craniomaxillofacial region have unique clinical and pathological features.

Tumor-induced osteomalacia: an important cause of adult-onset hypophosphatemic osteomalacia in China: Report of 39 cases and review of the literature

Tumor-induced osteomalacia (TIO) is an acquired form of hypophosphatemia. Tumor resection leads to cure. We investigated the clinical characteristics of TIO, diagnostic methods, and course after tumor resection in Beijing, China, and compared them with 269 previous published reports of TIO. A total of 94 patients with adult-onset hypophosphatemic osteomalacia were seen over a 6-year period (January, 2004 to May, 2010) in Peking Union Medical College Hospital. After physical examination (PE), all patients underwent technetium-99m octreotide scintigraphy ((99) Tc(m) -OCT). Tumors were removed after localization. The results demonstrated that 46 of 94 hypophosphatemic osteomalacia patients had high uptake in (99) Tc(m) -OCT imaging. Forty of them underwent tumor resection with the TIO diagnosis established in 37 patients. In 2 patients, the tumor was discovered on PE but not by (99) Tc(m) -OCT. The gender distribution was equal (M/F = 19/20). Average age was 42 ± 14 years. In 35 patients (90%), the serum phosphorus concentration returned to normal in 5.5 ± 3.0 days after tumor resection. Most of the tumors (85%) were classified as phosphaturic mesenchymal tumor (PMT) or mixed connective tissue variant (PMTMCT). Recurrence of disease was suggested in 3 patients (9%). When combined with the 269 cases reported in the literature, the mean age and sex distribution were similar. The tumors were of bone (40%) and soft tissue (55%) origins, with 42% of the tumors being found in the lower extremities. In summary, TIO is an important cause of adult-onset hypophosphatemia in China. (99) Tc(m) -OCT imaging successfully localized the tumor in the overwhelming majority of patients. Successful removal of tumors leads to cure in most cases, but recurrence should be sought by long-term follow-up.

Does Endothelial Chimerism Correlate With Renal Allograft Rejection?

BACKGROUND

The blood vessels of a transplanted organ are an interface between the donor and the recipient. The endothelium is believed to be a major target for graft rejection. After transplantation endothelial cells of a transplanted organ may be of recipient origin.

OBJECTIVES

In this study we sought to determine whether endothelial chimerism correlates with graft rejection.

METHODS

Biopsy samples from 34 renal transplants of female recipients who received kidneys from male donors were studied for the presence of endothelial cells of recipient origin. Formalin-fixed, paraffin-embedded tissue sections of renal biopsy samples were examined by fluorescence in situ hybridization (FISH) for the presence of endothelial cells containing two X chromosomes, using a biotinylated Y-chromosome probe and digoxigenin-labeled X-chromosome probe.

RESULTS

The FISH methods identified endothelial cells of recipient origin. Endothelial chimerism was common, irrespective of rejection. Its presence was focal with these elements, coexisting in the biopsy.

CONCLUSIONS

We observed no correlation between the percentage of recipient endothelial cells among vascular elements and the type of graft rejection (P > .05).

Giant cell reparative granuloma of the temporal bone

Giant cell reparative granuloma (GCRG) is an uncommon non-neoplastic lesion that typically occurs in the mandible and maxilla: however, its involvement with the temporal bone is rare. It is usually misdiagnosed as a giant cell tumor. Although regarded as a benign process, GCRG may be locally aggressive. In this paper, we describe two cases of GCRG of the temporal bone and review the pertinent literature published in English. The clinical course, histological evaluation, diagnosis, differential diagnosis, treatment and prognosis of GCRG of the temporal bone were investigated.