Purpose To investigate the clinicopathological features and significance of the uterine leiomyoma with massive lymphocytic infiltration(ULLI).Methods Four cases of uter-ine leiomyoma with massive lymphocyte infiltration were collect-ed for histological observation,immunohistochemical staining,EBER in situ hybridization,gene clonality analysis.Its clinical and pathological characteristics were analyzed,and relevant liter-atures were reviewed.Results All the patients clinically pres-ented with irregular vaginal bleeding and uterine masses,and underwent surgical resection of the tumors.These tumors,simi-lar to the common leiomyomas,had firm,whorled,white,pink or gray cut surfaces.Histological examination showed dense and diffuse lymphoid infiltration between the interwoven bundles of fusiform smooth muscle cells,mainly small lymphocytes,accom-panied by the formation of lymphoid follicles,almost masking the nature of the tumors.Immunohistochemical staining showed that the fusiform leiomyoma cells were positive for actin,α-SMA,desmin,and h-caldesmon.The infiltrated lymphocytes were positive for CD45,CD45RO,CD2,CD3,CD4,CD8,and TIA-1.The lymphatic follicles were positive for CD20,CD79a,and PAX5.EBER in situ hybridization was negative in all ca-ses.BIOMED-2 PCR analysis showed that 3 cases had clonal T cell receptor gene rearrangement,and 1 case with concomitant immunoglobulin gene rearrangement.The patients were followed up for 6-108 months and had no evidence of recurrence.Con-clusion ULLI is a rare morphological change in uterine leiomy-oma,where the extensive lymphocytic infiltration may mask the nature of the tumors.Awareness of this histological phenomenon in leiomyoma is of most importance to avoid misdiagnosis of lym-phoma.

Purpose To investigate the clinicopathological features and significance of the uterine leiomyoma with massive lymphocytic infiltration(ULLI).Methods Four cases of uter-ine leiomyoma with massive lymphocyte infiltration were collect-ed for histological observation,immunohistochemical staining,EBER in situ hybridization,gene clonality analysis.Its clinical and pathological characteristics were analyzed,and relevant liter-atures were reviewed.Results All the patients clinically pres-ented with irregular vaginal bleeding and uterine masses,and underwent surgical resection of the tumors.These tumors,simi-lar to the common leiomyomas,had firm,whorled,white,pink or gray cut surfaces.Histological examination showed dense and diffuse lymphoid infiltration between the interwoven bundles of fusiform smooth muscle cells,mainly small lymphocytes,accom-panied by the formation of lymphoid follicles,almost masking the nature of the tumors.Immunohistochemical staining showed that the fusiform leiomyoma cells were positive for actin,α-SMA,desmin,and h-caldesmon.The infiltrated lymphocytes were positive for CD45,CD45RO,CD2,CD3,CD4,CD8,and TIA-1.The lymphatic follicles were positive for CD20,CD79a,and PAX5.EBER in situ hybridization was negative in all ca-ses.BIOMED-2 PCR analysis showed that 3 cases had clonal T cell receptor gene rearrangement,and 1 case with concomitant immunoglobulin gene rearrangement.The patients were followed up for 6-108 months and had no evidence of recurrence.Con-clusion ULLI is a rare morphological change in uterine leiomy-oma,where the extensive lymphocytic infiltration may mask the nature of the tumors.Awareness of this histological phenomenon in leiomyoma is of most importance to avoid misdiagnosis of lym-phoma.

Objective:To study the clinicopathological features and immunophenotype of spindle cell/sclerosing rhabdomyosarcoma (SRMS) in adults and children, as well as its correlation with the expression and gene-mutations of MYOD1.Methods:Twenty cases of SRMS were collected at Xijing Hospital, Fourth Military Medical University from 2009 to 2019. These cases were evaluated for clinical, pathological, and immunohistochemical features. MYOD1 gene sequencing was performed on 12 cases with available tissue and sufficient DNA quantity using Sanger sequencing.Results:The 20 patients included 12 children and 8 adults, 11 males and 9 females, with an age range of 8 months to 85 years (mean 22 years). Most of them presented with a painless, progressively enlarged solid mass. The tumors occurred in head and neck (7 cases), abdominal and pelvic cavity (7 cases, including 4 in abdominal cavity, 2 in pelvic cavity, 1 in abdominal and left thoracic cavity), upper limb (5 cases, including 2 in left shoulder, 1 in right armpit, 1 in right humerus, and 1 in left forearm), and the back (1 case). The diameter of these tumors ranged from 2.5 to 20 cm, with a mean of 6.2 cm. Histologically, all of the tumors were mainly composed of spindle cells arranged in fascicles, and in 7 cases, at least in part, arranged in herringbone pattern, resembling adult fibrosarcoma. Foci reminiscent of interstitial sclerosing were presented in 4 cases, pseudovascular structures in 2 cases, loosely myxoid stroma in 4 cases, and varying degree of necrosis in 9 cases. A various number of spindled or polygonal rhabdomyoblasts were observed between spindle cells in 3 cases.Among them,16 cases showed spindle cell morphology, 2 cases showed scleroisng morphology, and 2 cases showed a hybrid phenotype of spindle, sclerosing and primitive undifferentiated areas. Immunohistochemically, the tumor cells were positive for desmin, Myogenin and/or MyoD1, but negative for CKpan, ALK1, CD34, EMA, HMB45, SMA, H-cald and S-100. Four cases (4/12) harbored a homozygous or heterozygous MYOD1 (p.L122R) mutation. MYOD1-mutant SRMS usually had diffuse and strong nuclear MyoD1 positivity. Follow-up was available in 12 cases, ranged from 1 to 51 months. At the end of follow-up period, 3 patients died of the disease, 3 patients developed local recurrences, 2 patients survived with disease.Conclusions:SRMS is a rare type of rhabdomyosarcoma, and more commonly occurs in the head and neck of children than adults. MYOD1-mutant SRMS usually had diffuse and strong nuclear MyoD1 positivity, frequently associated with a more aggressive behavior.

Objective: To analyze the clinical and pathological features of Kaposiform hemangioendothelioma (KHE), and to investigate the role of master transcriptional factor Prox-1 in the regulation of lymphatic differentiation. Methods: Nine cases of KHE (during the period from October 2009 to June 2016) were collected with clinical and pathological data. H&E stained section review and immunohistochemietry using the Dako EnVision method were performed. Results: There were 6 female and 3 male patients with age ranging from 2 months to 8 years (median 3 years and 4 months). The patients presented with either single subcutaneous soft tissue mass, or bone tumors, with the duration of disease onset ranging from 1 month to 1 year. The sites of involvement included the skins of neck (2 cases), nose root (1 case), inguinal (1 case), thigh root (1 case), humerus (2 cases), lumbar vertebrae(1 case), and mesentery (1 case). These tumors were histologically composed of nodules of densely packed spindle or ovoid cells and deformed small blood vessels in an invasive growth pattern. The tumor cells were immunohistochemically positive for both blood vessels and lymphatic endothelial markers, including Prox-1, the master transcriptional factor, and VEGFR-3. With followed-up from 1 to 60 months (median 26 months), two patients died of the disease, while the remaining patients were alive without recurrence. Conclusions KHE is a rare vascular tumor with at least partial lymphatic endothelial differentiation, in which Prox-1 may act as a master regulator for such differentiation. KHE is an aggressive tumor of intermediate malignant potential, with local invasion and recurrence tendency, and long term follow-up is required.

Objective: To investigate the multidirectional differentiation potential in epithelioid sarcoma (ES), with special emphasis on its mesothelial and lymphatic endothelial markers expression. Methods: Ten cases of distal-type ES were included. The clinical, histological, and immunohistochemical(including mesothelial and lymphatic endothelial markers expression)features and follow-up data were evaluated. Results: The patients aged between 8 to 66 years. Five cases were male and five were female. The tumors were located at the palm (2 cases), wrist (3 cases), upper arm (2 cases), poplitealfossa (1 case), lower leg (1 case) and thigh (1 case), respectively. Clinically, most cases presented as painful, firm subcutaneous nodules. Histologically, the tumors were mainly composed of epithelioid, rhabdoid, spindle, or transitional cells, with abundant eosinophilic cytoplasm, oval and vesicular nucleus, and one or more prominent nucleoli. They were arranged in nodular, diffuse nodular or sheet like growth patterns, frequently with necrosis at the center with vague granulomatous configuration. Immunohistochemically, all tumors expressed cytokeratins, epithelial membrane antigen, CD34, desmin, mesothelial markers such as Calretinin, WT1, D2-40, M2A, vascular and lymphatic endothelial markers FLI-1, and VEGFR-3. The tumor cells did not express CD31, FⅧRAg, HHF35, HMB45, Melan A, MyoD1, myogenin, S-100 protein and SMA. All 10 patients underwent radical resection or extended excision, with additional radiotherapy or chemotherapy. During the follow-up from October 2012 to August 2016, seven cases showed recurrences and metastases within 2 months to 2 years. Five patients died of the disease due to widespread metastases. Conclusions ES may show a wide spectrum of morphology, and display a multidirectional differentiating capabilities including towards mesothelial and lymphatic endothelial cells. As such, its diagnosis and differential diagnosis are particularly important as it is easily confused with other tumors with similar morphology or immune phenotype.

Objective: To investigate the morphological features, diagnosis and differential diagnosis of extrapleural sarcomatoid malignant mesothelioma (SMM). Methods: Six cases of extrapleural SMM were evaluated for their clinical, histological, immunohistochemical features, and prognosis. Results: Patients included 3 men and 3 women, with a median age of 60 years (range 41-75 years). All patients had no asbestos exposure in history and no pleural lesions. The tumors involved peritoneum (3 cases), bone (2 cases), and neck soft tissue (1 case). Histologically, the tumors were mainly composed of slender to plump spindle cells with occasional polymorphic cells, arranged in fascicular to storiform pattern or haphazardly organized, closely resembling those of fibromatosis, fibrosarcoma or malignant fibrous histiocytoma. The tumor cells were imunohistochemically positive for cytokeratin (pan, 6/6), calretinin (5/6), podoplanin (6/6), D2-40 (4/6), vimentin (6/6), WT1 (4/6), CD10 (3/6), SMA (4/6), and variably positive for CK7, and CK8/18, but were negative for other linage-specific markers. The Ki-67 proliferation indexes ranged from 25% to 55%, consistent with the diagnosis of malignant mesothelioma of the sarcomatous type. Ultrastructurally, the tumor cells possessed discontinuous external lamina, cytoplasmic processes, microfilaments and desmosomal intercellular junctions. Local recurrence or metastasis was seen in 1 case and 4 cases, respectively, after surgery, and all the patients died of the disease within 9 months. Conclusions Extrapleural SMM, although rare, should be considered as a differential diagnosis among other benign or malignant sarcomatoid tumors and sarcomas. Along with clinical and radiological presentation, the combination of broad-spectrum cytokeratin, vimentin, and a series of mesothelial markers are useful for diagnosis of SMM.

Bone Neoplasms ; immunology ; pathology ; Child ; Humans ; Osteosarcoma ; immunology ; pathology ; Rosette Formation

Carcinoma ; pathology ; Humans ; Paranasal Sinus Neoplasms ; pathology

Bone Neoplasms ; pathology ; Chondrosarcoma, Mesenchymal ; pathology ; Dura Mater ; pathology ; Humans ; Meninges ; pathology

ADP-ribosyl Cyclase 1 ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Biomarkers, Tumor ; metabolism ; Biopsy ; Bone Neoplasms ; drug therapy ; metabolism ; pathology ; CD56 Antigen ; metabolism ; Humans ; Ilium ; Interferon Regulatory Factors ; Male ; Middle Aged ; Multiple Myeloma ; drug therapy ; metabolism ; pathology ; Syndecan-1 ; metabolism