Collagen composition and ultrastructure of the so-called amianthoid fibres in palisaded myofibroblastoma. Ultrastructural and immunohistochemical study.

A very prominent feature of the recently described intranodal palisaded myofibroblastoma is the occurrence of stellate crystalline extracellular deposits known as 'amianthoid fibres', and thought to represent abnormally thick collagen fibrils. We showed at the ultrastructural level that these deposits are composed of fibrils with the periodicity and width typical of normal native collagen. Using antibodies directed against various extracellular components, we have determined that these structures contain type I and III collagens. Our results indicate that the crystalloid deposits in intranodal palisaded myofibroblastoma called 'amianthoid fibres' do not contain giant collagen fibrils widely regarded as characteristic of the morphological concept 'amianthoid' in other locations.     

Idiopathic multicentric Castleman's disease. A clinicopathologic and immunohistochemical study of five cases

Several lymphoproliferative disorders may be interpreted as multicentric Castleman's disease (MCD) clinicopathologically. These include HIV infection, autoimmune-disease-associated lymphadenopathy, idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia, "idiopathic MCD", POEMS syndrome (polyneuropathy, anasarca, organomegaly, endocrinopathy, M-proteins, and skin lesions), and non-Hodgkin's lymphomas. Among these, idiopathic MCD appears to be relatively rare. We report on the clinicopathologic and immunohistologic findings of five cases of idiopathic MCD and discuss the problems regarding their differential diagnosis. Some of the characteristic clinical findings of POEMS syndrome, including hepatosplenomegaly, skin change, endocrine abnormalities and anasarca, were present in all five cases. However, during the course of disease, minimal diagnostic criteria for POEMS syndrome, i.e., monoclonal plasma cell proliferation and sensory motor neuropathys, were absent in all five cases. The serum interleukin-6 level and the vascular endothelial growth factor level were found to be elevated in two of the cases examined. Various autoantibodies were detected in three cases. However, none of them fulfilled the diagnostic criteria for any of the definite autoimmune-disease. Histologically, three lesions exhibited a mixed type of Castleman's disease, and two exhibited the hyaline-vascular type. The majority of the germinal centers were of the hyaline-vascular or epithelioid germinal type, with a few hyperplastic germinal centers. The interfollicular area was characterized by prominent vascularity. Moderate to large sheets of plasma cells were observed in three mixed type cases. The polytypic nature of B-lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction. Immunohistochemical study demonstrated that the majority of germinal centers exhibited a tight/concentric pattern of FDC network. Few CD57-positive T-cells were observed in the hyaline-vascular and epithelioid follicles. The lack of CD57-positive T-cells appears to be related to the formation of abnormal germinal centers in the MCD.     

Sialoblastoma: a clinicopathologic and immunohistochemical study of 7 cases

Sialoblastoma is a rare congenital or perinatal salivary tumor that varies in histologic features and biologic potential. Seven cases from the files of the Armed Forces Institute of Pathology are presented. These tumors occurred in 4 males and 3 females with ages ranging from prenatal to 6 months at the time of discovery. Five lesions originated from the parotid gland; 2 lesions were from the submandibular gland. All lesions presented as nodular to multinodular swellings and ranged in size from 2.0 to 7.0 cm. The principal sign or symptom was rapid growth. Two histologic patterns with differing behavior predominated: (1) a favorable pattern had semiencapsulation of cytologically benign basaloid tumor cells with intervening stroma; and (2) an unfavorable histology of anaplastic basaloid tumor cells, minimal stroma, and broad pushing to infiltrative periphery. Four and three tumors had favorable and unfavorable growth patterns, respectively. One unfavorable lesion had vascular invasion, and another demonstrated perineural invasion. All 3 tumors with unfavorable histology recurred. Tumor cells in 3 cases were immunohistochemically reactive for keratin, S-100, smooth muscle actin, and calponin to varying degrees. All 3 tumors were reactive for p63. alpha-Fetoprotein was expressed in 2 unfavorable tumors. Ki67 was expressed at 3% in a favorable tumor and 40% and 80% in the 2 unfavorable lesions. Treatment involved surgical excision. One patient received adjuvant chemotherapy. Two sialoblastomas resulted in recurrences within a year and another developed a recurrence after 4 years. One sialoblastoma developed lung metastasis within 1 month of the original biopsy. Although a clinical correlation is suggested by a favorable/unfavorable histologic grading system the biologic behavior is nonetheless considered unpredictable.     

Intranodal myofibroblastoma presenting in the submandibular region: evidence of a broader clinical and histological spectrum

Intranodal myofibroblastoma is an uncommon benign mesenchymal tumour of lymph nodes which was first described in May 1989. All the cases described to date have presented exclusively in the groin, a feature which has been regarded as distinctive. Two new cases are presented herein, both of which arose in the submandibular region of middle-aged females. Both lesions showed histological features marginally different from the cases originally described, which may reflect their different anatomical location. Immunohistochemical staining revealed positivity for muscle-specific actin (HHF 35), as previously described, and ultrastructural examination in one case confirmed the presence of myofibroblasts. The data presented suggest that this distinctive lesion has a broader clinicopathological spectrum than previously realised.     

栅状肌纤维母细胞瘤3例报道及文献复习

目的：观察栅状肌纤维母细胞瘤的临床病理特征，探索该肿瘤的组织来源及石棉样纤维的性质和来源。方法：对３ 例栅状肌纤维母细胞瘤进行组织形态学和免疫组织化学研究，结合文献对本病的诊断标准、鉴别要点及组织来源进行探讨。结果：栅状肌纤维母细胞瘤的组织学特点为梭形肿瘤细胞呈交叉束状、栅栏状排列，间质内有较多出血、散在的肥大细胞，肿瘤中出现石棉样纤维。免疫组化见肿瘤细胞及石棉样纤维星芒状突起中ａｃｔｉｎ、ｖｉｍｅｎｔｉｎ 呈阳性表达，ｄｅｓｍｉｎ、Ｓ１００ 、ＦａｃｔｏｒⅧ、ｃｙｔｏｋｅｒａｔｉｎ 呈阴性表达。结论：栅状肌纤维母细胞瘤是一种具有独特临床病理特征的肌纤维母细胞瘤，该肿瘤来源于肌纤维母细胞或特殊平滑肌细胞亚型。石棉样纤维中心为血管周围胶原的变性，星芒状纤维为增殖的肌纤维母细胞突出的中间丝和微丝。     

Primary gastric inflammatory myofibroblastic tumor: A clinicopathologic and immunohistochemical study of 5 cases

Primary gastric inflammatory myofibroblastic tumors are rare. Here we report on 5 such cases (4 males and 1 female, age range 36–45 years). Their presenting symptoms included abdominal mass (5 patients), abdominal pain (4 patients), and upper gastrointestinal hemorrhage (1 patient). Tumor size ranged from 4.5 to 8 cm in the greatest dimension. Histologically, these tumors showed three patterns: myxoid hypocellular, fascicular, and hyalinized. A lymphoplasmacytic infiltrate was present in all 5 tumors. One to two mitotic figures were recognized in 10 high power fields (HPFs) in 4 patients and focally up to 5 in 10 HPFs in 1 patient. No prominent nuclear atypia or necrosis was observed. ALK, smooth muscle actin, and vimentin staining were observed in all tumors. One tumor focally expressed desmin. S-100, CD21, CD34, CD35, CD68, and CD117 were negative in all IMTs. The patients were followed up for 2–5 years (mean 3.4 years), and none of them had tumor metastasis or died. Only one patient developed local recurrence and is now alive with no evidence of disease after the second surgery (11 months after the second surgery). Our results indicate that primary gastric IMTs have an intermediate behavior as seen at other sites.     

Pleomorphic adenoma of the breast: A clinicopathologic and immunohistochemical study of 10 cases

Pleomorphic adenomas of the breast (PAB) are uncommon tumors. We studied the clinicopathologic features of 10 cases of PAB, seven of which were assessed immunohistochemically. Nine patients were women, with a median age at diagnosis of 65 years. Eight patients presented with a palpable mass; two had a nipple discharge. Nine of the tumors were periareolar. The latter epidemiologic findings, coupled with histologic observations, appeared to indicate a preferential origin for PAB within large intramammary ducts. These neoplasms histologically resemble their analogues in salivary glands. Moreover, a gradual histologic transition between different morphologic areas in PAB, especially between mesenchymal and epithelial regions, supported the contention that the neoplasm arises from a single cell type capable of divergent differentiation and thus should not be considered a "mixed" tumor. This contention was further substantiated by immunohistochemical findings, in which three intermediate filaments (cytokeratin, vimentin, and glial fibrillary acidic protein) and muscle-specific actin were expressed conjointly in tumor cells with a variety of morphologic appearances. In addition, cells differentiating along mesenchymal lines by conventional microscopy were found to express epithelial membrane antigen or gross cystic disease fluid protein-15 in five cases. The benign nature of PAB was supported by a lack of metastases in this series during a median follow-up period of 4.9 years. However, one lesion recurred locally. Regarding therapy, we believe that PAB can be excised successfully with only a narrow circumferential margin of uninvolved breast.     

胚胎发育不良性神经上皮瘤与皮质发育不良

目的观察胚胎发育不良性神经上皮瘤（DNT）的病理形态学及免疫组织化学特点,探讨其与皮质发育不良之间的关系以及组织来源。方法应用光镜和免疫组织化学EnVision法对14例DNT进行观察分析,并对患者进行长期随访。结果肿瘤位于颞叶的有11例,镜下由神经元和神经胶质成分混合构成,9例可见“特异的胶质神经元结构”。1例为简单型,8例为复杂型,5例为非特异型。11例标本充足的病例10例伴有皮质发育不良改变,表现为分子层和（或）白质内异位神经元数量增多（7例）,分子层内可见成行的外颗粒细胞层残留（4例）,脑皮质的结构异常（10例）,以及出现异常形态的神经细胞。免疫组织化学染色少突胶质样细胞（OLC）均呈现Olig2的免疫反应性,部分OLC表达nestin、微管相关蛋白2、神经丝蛋白、胶质纤维酸性蛋白,但神经元核抗原呈阴性。癫痫控制结果Ⅰ级12例,Ⅱ级2例,无肿瘤复发。结论DNT与皮质发育不良关系密切,应用免疫组织化学染色有助于DNT和皮质发育不良的诊断。     

Oncocytoma-like angiomyolipoma. A clinicopathologic and immunohistochemical study of 2 cases

We report the clinical, pathologic, and immunohistochemical features of an unusual tumor of the kidney composed of densely eosinophilic, polygonal epithelioid cells. The patients were a 56-year-old woman and a 35-year-old man. The renal tumors were discovered during follow-up for breast carcinoma and evaluation for abdominal pain, respectively. The tumors closely resembled oncocytoma in routine sections, but were negative for epithelial markers and positive for HMB-45, a pattern of reactions characteristic of angiomyolipoma. In the woman, a single additional microscopic angiomyolipoma was present in the renal parenchyma at a distance from the main tumor. Both patients are alive without recurrence 7 and 10 years after surgery, respectively. Based on clinical, morphologic, and immunophenotypic features, we conclude that these tumors are oncocytoma-like angiomyolipomas.     

Lymph node involvement by Langerhans cell histiocytosis: a clinicopathologic and immunohistochemical study of 20 cases

Twenty cases of Langerhans cell histiocytosis (LCH) involving lymph nodes with no other sites of disease are presented. The patients were 12 men and 8 women between 3 months and 68 years of age. Seven patients were younger than 11 years; the other 13 patients were older than 16 years. Clinically, all patients presented with lymphadenopathy and underwent excisional biopsy; clinical and imaging studies did not reveal abnormalities in other organs. Cervical lymph nodes were most commonly involved; other lymph nodes involved included axillary, inguinal, and supraclavicular. Histologically, LCH in lymph nodes had 3 main architectural patterns: (1) preserved nodal architecture with subtle involvement, (2) subtotal effacement of nodal architecture, and (3) total effacement of nodal architecture. There was a gradient of involvement by LCH from focal sinus involvement to diffuse sinus involvement and from focal paracortical involvement to diffuse paracortical involvement. In some cases, focal involvement was initially unrecognized because of the subtle nature of the changes in the lymph node, posing difficulties for diagnosis. Langerhans cells in the involved areas showed strong positivity by immunohistochemical studies for S100 protein and CD1a in all 11 cases assessed. In conclusion, LCH can initially manifest clinically with involvement limited to lymph nodes. Recognition of the different patterns of LCH, particularly cases with subtle involvement, is important for recognizing this disease and separating LCH from other more common causes of lymphadenopathy.     

弥漫性大B细胞淋巴瘤的临床病理和免疫组织化学特征

目的 探讨弥漫性大B细胞淋巴瘤临床和病理组织特征以及免疫组织化学特异性抗体在其诊断和鉴别诊断中的价值。方法 收集60例弥漫性大B细胞淋巴瘤,总结其临床资料和病理学特点,用免疫组织化学EnVision^TM两步法标记白细胞共同抗原（LCA）、L26、BLA36、CD30和bcl-6抗体。结果 76．7％（46／60）弥漫性大B细胞淋巴瘤的发病年龄集中在40－70岁,淋巴结内外均可累及,90．0％（54／60）患者临床分期为Ⅱ（24／54）、Ⅲ（21／54）、Ⅳ（9／54）期。组织病理形态：中心母细胞淋巴瘤占88．3％（53／60）,免疫母细胞淋巴瘤占3．3％（2／60）,间变性大细胞淋巴瘤占3．3％（2／60）,富于T细胞的B细胞淋巴瘤占5．0％（3／60）。免疫标记LCA、L26、BLA36表达率为100．0％（60／60）,CD30表达率为3．3％（2／60）,bcl-6表达率为95．0％（57／60）。结论 弥漫性大B细胞淋巴瘤是一组异质性肿瘤,侵袭性大,必需结合其组织病理形态和特异抗体的免疫组织化学检测进行诊断和鉴别诊断。     

Sinonasal malignant melanoma. A clinicopathologic and immunohistochemical study of 14 cases.

The clinical, light microscopic, and immunohistochemical features of 14 sinonasal malignant melanomas were studied to show their diverse morphologic appearance and distinction from therapeutically more amenable neoplasms that occur in this region. The tumors arose in 6 men and 8 women (median age, 70 years). Eleven patients died of disease 7 to 44 months (median, 18 months) after diagnosis. The absolute median survival time was 18.5 months (range, 7 to 44 months). The predominant microscopic appearance was categorized as small blue cell in eight cases, spindle cell in three cases, epithelioid in two cases, and pleomorphic in one case. Eight tumors had multiple patterns. Five sinonasal malignant melanomas had theque-like growth, five had junctional change, and 10 contained at least rare melanin pigment. Fourteen, 13, and 12 sinonasal malignant melanomas were immunoreactive with anti-vimentin, HMB45, and anti-S100 protein antibodies, respectively. One epithelioid tumor positive for vimentin, S100, and HMB45 also contained scattered epithelial membrane antigen-positive and cytokeratin-positive cells, which emphasizes the need for a battery of stains to distinguish sinonasal malignant melanoma from carcinoma. All tumors were negative for leukocyte common antigen, muscle-specific actin, and synaptophysin. Diffuse immunopositivity for vimentin, S100 protein, and HMB45 allows distinction of sinonasal malignant melanomas from histologically similar neoplasms.     

肾恶性横纹肌样瘤15例临床病理及免疫组织化学分析

报道１５例肾恶性横纹肌样瘤（ＭＲＴＫ）的临床病理及免疫组化特点。男女之比为２．８：１。年龄４个月至４岁７个月，平均１岁零６个月。随访１０例，８例均于术后半年内死１０亡，２例健在。典型组织学改变为细胞弥漫排列，多边形，胞浆丰富嗜酸性，核仁突出。部分细胞胞浆内有嗜酸性包涵体，部分病例可见上皮样排列，间质硬化及梭形细胞成分。免疫组化显示１５例Ｖｉｍｅｎｔｉｎ（＋），１２例ＥＭＡ（＋），８例Ｃｙｔｏｋｅｒａｔｉｎ（＋）。结果提示，本瘤是一种好发于婴幼儿、预后差、多表现型的恶性肾肿瘤。可能来源于某种具有双向分化能力的多潜能细胞。     

34例脊索瘤的临床病理及免疫组织化学研究

为了解脊索瘤的临床病理及免疫组化特点，我们对34例脊索瘤进行了临床病理学及免疫组织化学标记的研究，并以5例软骨肉瘤作为对照。根据有无软骨样区域，将脊索瘤分为两型：软骨样脊索瘤（14例）和经典型脊索瘤（20例）。软骨样脊索瘤发病年龄（平均40．9岁）较经典型（平均51．1岁）年轻。7例（50％）软骨样脊索瘤发生于骶尾部，4例（28．6％）发生于颅底蝶枕部。免疫组化标记染色显示：34例脊索瘤均对细胞角蛋白呈阳性反应，16例（47．1％）对上皮性膜抗原阳性；而5例软骨肉瘤均对细胞角蛋白和上皮性膜抗原阴性。波形蛋白及S-100蛋白在大部分脊索瘤及5例软骨肉瘤中均呈阳性巨应。其结果验证了脊索瘤的双重特性──上皮性及间叶性；同时也说明了免疫组化染色对鉴别脊索瘤和软骨肉瘤很有帮助。     

Malignant mesothelioma with prominent adenomatoid features: a clinicopathologic and immunohistochemical study of 10 cases

The clinicopathologic and immunohistochemical features of 10 cases of pleural malignant mesothelioma with predominantly adenomatoid growth pattern are described to determine the clinical, histologic, and behavioral features of these tumors and to highlight the importance of separating this unusual pattern from the benign adenomatoid tumor. Seventy-seven cases of pleural biopsy and extrapleural pneumonectomy specimens for malignant mesothelioma were examined to identify the specific type of histologic growth pattern exhibited by the tumors. The 10 cases herein described were identified as an unusual histopathologic subset of these tumors. Nine patients were men and one was a woman with an age range of 56 to 82 years (mean, 68.5 years). The main presenting symptoms included cough, dyspnea, and chest pain. The typical features of pleural malignant mesothelioma were noted both radiologically and macroscopically. The tumors were characterized by diffuse pleural thickening with confluent nodular patches of tumor obliterating the pleural space. Histologically, a distinct morphology was observed composed of small tubular spaces lined by epithelioid cells, reminiscent of adenomatoid tumors of the genital tract. Immunohistochemical studies confirmed the mesothelial nature of the tumors. Clinical follow-up in 7 of 7 patients demonstrated a mean survival of 10 months from time of diagnosis. Adenomatoid mesothelioma is an unusual variant of epithelioid malignant mesothelioma that histologically may mimic a range of other tumors, including benign adenomatoid tumors and metastases of adenocarcinoma to the pleura. The clinical presentation, infiltrative growth, distinct histologic features, cytologic atypia and immunohistochemical profile all serve to differentiate adenomatoid malignant mesothelioma from other infiltrative processes involving the pleura.     

Mammary myofibroblastoma: report of two cases with fine-needle aspiration cytology and review of the cytology literature

Fine-needle aspirates from two histologically, immunohistochemically, and ultrastructurally confirmed mammary myofibroblastomas (MM) of two elderly women revealed abundant, randomly arranged single and clustered benign spindle-shaped mesenchymal cells with scant cytoplasm and elongated or oval nuclei displaying a finely granular chromatin pattern and inconspicuous nucleoli. In one case a few cells showed inconspicuous nuclear grooves. The aspirated tumor cells from the other case stained positively with desmin and CD34 antibodies and negatively with cytokeratin and S-100 protein antibodies, in keeping with an MM. A review of the literature was briefly presented.     

Primary angiosarcomas of the anterior mediastinum:: A clinicopathologic and immunohistochemical study of 9 cases

We report 9 cases of primary angiosarcomas of the anterior mediastinum. Patient ages ranged from 25 to 62 years (mean, 40.7 years); 5 patients were male and 4 were female. Main presenting symptoms included chest pain, dyspnea, and cough. The tumor size ranged from 3 to 12.5 cm. Macroscopically, the lesions were ill-defined hemorrhagic masses. Histologically, the growth patterns ranged from large vascular spaces to capillary-like proliferations. These were either lined by bland or more pleomorphic endothelial cells. The mitotic activity was variable and corresponded to the degree of differentiation. A rim of thymic tissue was observed in 2 cases suggesting a thymic origin of the tumors. No teratomatous components were identified. Immunohistochemical studies showed that all 9 cases were reactive for vascular markers including factor VIII–related antigen, CD31, and CD34, and negative for cytokeratin CAM5.2. All cases were treated by complete resection and 3 patients received adjuvant chemotherapy. Follow-up information available for 6 patients revealed that 4 were alive and free of disease at intervals ranging from 6 to 36 months after diagnosis and 1 was alive with recurrence at 48 months. One patient had died of the disease 10 months after diagnosis. Primary angiosarcomas of the anterior mediastinum are rare tumors that need to be added to the differential diagnosis of primary anterior mediastinal neoplasms. Despite their histologic similarity to angiosarcomas at other sites, primary angiosarcomas of the anterior mediastinum appear to follow a more protracted clinical course than their counterparts in other organ systems.