Lymphomatoid granulomatosis. Light microscopic, electron microscopic and immunohistochemical study

A case of lymphomatoid granulomatosis (LYG) involving the lungs, skin, stomach, and possibly the left kidney in a 60-year-old man is presented. The infiltrates in the lungs, stomach, and skin showed a polymorphic appearance, and consisted predominantly of lymphocytes of mature and blastic form and of a few neutrophils, plasma cells, and histiocytes. Most lymphoid cells showed irregularly shaped nuclei and clustered dense bodies, characteristics indicative of T lymphocytes. An immunohistochemical study confirmed the T cell origin of the lymphocytes; i.e. they were positive for Leu-1, Leu-3a and Ia-like antigens but negative for Leu-2a antigen and the antibodies against light chains. The homogeneity of the major population of infiltrates in LYG indicates that at least some forms of LYG may be neoplastic or pre-neoplastic lymphocytic disorders which may ultimately progress to malignant lymphoma.     

实验性兔颈动脉粥样硬化的光镜和电镜观察

目的：评价空气干燥加高脂饮食法建立的颈动脉粥样理化（AS）的动物模型的病理变化。方法：54只日本大耳兔分为3组,分别给予空气干燥加高脂饮食（n=24),单纯高脂饮食对照（n=24)和正常饮食对照（n=6),在实施空气干燥后的第3天,1周,2周,4周分别处死动物,观察颈动脉病变的光镜,电镜特征。结果：空气干燥法加高脂饮食组出现较典型的AS病变,包括内皮细胞再生,内膜增厚和新生血管的出现,平滑肌细胞移行增殖,脂质吞噬沉积,弹力纤维和胶原基质的生成等。实验组2周,4周时内膜增生明显,而单纯高脂饮食对照组的颈动脉和空气干燥组的对侧颈动脉未发现明显的AS病变,结论：空气干燥加高脂饮食法可以形成典型的颈AS病变。     

Two cases of acquired toxoplasmic lymphadenitis. Light and electron microscopic and immunohistochemical studies

We report two cases of acquired toxoplasmic lymphadenitis, one with toxoplasmic cysts and the organisms of Toxoplasma gondii and the other with the organisms only. These cysts and organisms were observed in paraffin-embedded sections, touch smears and ultrathin sections for electron microscopy. Touch smears were especially valuable for the quick and accurate diagnosis of toxoplasmic lymphadenitis. We also studied immature sinus histiocytosis (ISH) in these cases. The predominant cells of ISH were confirmed to be B lymphocytes immunohistochemically, the majority being positive for polyclonal surface IgM. ISH was observed in the perifollicular and paracortical areas surrounding post-capillary venules (PCV), whereas the sinuses were only partially involved.     

Histiocytic sarcoma in Wistar rats. A light microscopic, immunohistochemical, and ultrastructural study

Histiocytic sarcoma, a recently described tumor entity in rats, was studied by light microscopy in 20 male and female Wistar rats. The tumors originated from subcutaneous tissues; metastasis involved primarily the liver with sinusoidal spread and the lungs with peribronchiolar distribution. The characteristic features of this tumor were the uniform population of tumor cells, palisading necrosis, and abundant multinucleated giant cells. Immunocytochemical and ultrastructural findings confirmed the histiocytic nature of the tumor cells.     

Granular cell basal cell carcinoma. Light microscopy,immunohistochemical and ultrastructural study

Summary Granular cell basal cell carcinoma (BCC) is a rare histological variant of BCC. In this, the fifth reported case, a 67-year-old male with BCC located on the nose, light microscopy examination showed a tumour with the classical configuration of nodular BCC, in which most cells had finely granular eosinophilic cytoplasm. Ultrastructural observation showed numerous lysosome-like granules filling the cytoplasm of tumour cells, along with numerous well-formed pentalaminate desmosomes. Immunohistochemical profile (including positivity for keratins C 5.2 and AE 1 and for Leu-M1), together with the presence of cytoplasmic tonofilament bundles and desmosomes, are consistent with the proposed epithelial origin of granular cells in this tumour.     

Pulmonary carcinosarcoma: immunohistochemical and ultrastructural studies

A case of pulmonary carcinosarcoma in a 68-year-old male patient is reported. The tumor in the resected left upper lobe extended mainly endobronchially, invading the normal bronchial lumina and mucosa. The carcinomatous component consisted of poorly differentiated squamous cell carcinoma and was mainly located in the periphery of the tumor nests. The sarcomatous component consisted of chondrosarcoma and was mainly located in the center of the tumor nests. Tumor cells in the sarcomatous component reacted with anti-S-100 protein antibody and were surrounded with abundant homogeneous extracellular matrix staining positively with Alcian blue. The transition from the carcinomatous component to the sarcomatous component appeared to be very smooth. The tumor cells in both the carcinomatous and sarcomatous components reacted with anti-epithelial membrane antigen antibody. Ultrastructurally, the tumor cells with tonofibrils in the carcinomatous component were apposed and connected to each other by desmosomes. By contrast, in the sarcomatous component, the tumor cells had well-developed and dilated rough endoplasmic reticulum and were arranged loosely in a myxomatous matrix. Some tumor cells in the sarcomatous component had occasional tonofibrils, and were apposed and connected to each other by desmosome-like structures. It is shown for the first time, ultrastructurally and immunohistochemically, that the tumor cells in the sarcomatous component of pulmonary carcinosarcomas have features of both epithelial and mesenchymal cells. It is suggested that the sarcomatous component in the present case is derived from the carcinomatous component.     

Elastosis in lung carcinoma: immunohistochemical, ultrastructural and clinical studies

Elastosis is the pathological finding of focal deposits of elastic fibers in abnormal amounts within tissue. It is well described in the case of infiltrating carcinoma of the breast, but elastosis in lung carcinoma has not been previously documented in detail. We investigated the characteristics of elastosis in lung carcinoma with light and electron microscopies, and immunohistochemistry for alpha-1-antitrypsin. A total of 184 surgically resected primary lung carcinomas were studied. Elastosis was detected in adenocarcinomas (85/106), squamous cell carcinomas (11/60) and adenosquamous carcinomas (5/7), but not in small-cell carcinomas (n = 4) or large-cell carcinomas (n = 5). The degree of elastosis in each case was divided into one of five grades, graded as 3+ to 1-. The score of elastosis was significantly higher in adenocarcinoma than that in squamous-cell carcinoma (P<0.01). In the cases of adenocarcinoma, the mean score of elastosis in the well-differentiated type (WD n = 43) was higher than that in the moderately differentiated (MD) (n = 39; P = 0.012) and poorly differentiated (PD) types (n = 24; P<0.01). The mean score of elastosis in MD adenocarcinoma was also higher than that in the PD type (P<0.01). Light- and electron-microscopic analyses revealed that these elastic fibers in elastosis were composed of aggregates of thick mature and fine immature elastic fibers, and were positive for alpha-1-antitrypsin. It is suggested that both degraded elastic fibers and newly synthesized fibers are contained in the elastosis of lung carcinoma. Although no significant evidence was detected to suggest any correlation between elastosis and the degree of tumor invasion, the survival curves of adenocarcinomas with elastosis showed a significantly improved prognosis than of those without elastosis in the cases of stages IA and IB (n = 52; P = 0.026).     

Pituitary adenoma in Carney complex: an immunohistochemical,ultrastructural, and immunoelectron microscopic study

First described in 1985, Carney complex is a rare, heritable disorder featuring abnormal skin pigmentation, cardiac and cutaneous myxoma, melanotic schwannoma of psammomatous type, and endocrine abnormalities, including pituitary adenomas. Patients with the latter present with elevated growth hormone (GH) levels and acromegaly or gigantism. Prolactin (PRL) elevation may also be seen. The authors have investigated 2 resected pituitary adenomas from patients with Carney complex. One, a 19-year-old female acromegalic with elevated GH, IgF-1, and PRL levels, had a mammosomatotroph adenoma immunoreactive for GH and PRL. Ultrastructurally, GH and PRL were present in the same secretory granules. The second patient, a 27-year-old acromegalic, had a sparsely granulated GH cell adenoma that by immuno-electron microscopy revealed GH immunoreactivity only. The lack of morphologic similarity between the 2 adenomas indicates that pituitary tumors in patients with Carney complex may not exhibit the same phenotype.     

Neuroendocrine carcinomas of the skin: light microscopic, ultrastructural, and immunohistochemical analysis

Three primary skin carcinomas were analyzed by light microscopy, immunohistochemistry, and electron microscopy. In all cases, local recurrences, regional lymph node metastases, distant metastases, or all three developed. One patient had elevated serum calcitonin levels that did not decrease after thyroidectomy but did return to normal after removal of the skin tumor recurrences, its metastases, or both. The tumor cells were arranged in solid clusters; a trabecular arrangement was occasionally seen. In 2 cases the cells were of intermediate size and showed vesicular central nuclei and pale, moderately abundant cytoplasm. In the remaining case the cells were distinctly smaller and either round or fusiform. Mitoses were more abundant in the latter case than in the former two. By immunohistochemistry, calcitonin- and somatostatin-containing cells were demonstrated in all cases and ACTH in one. By electron microscopy, the cases consisting of intermediate-size cells displayed moderately abundant neurosecretory-type granules irregularly dispersed throughout the cytoplasm. The case consisting of smaller cells displayed fewer and smaller granules that tended to concentrate in slender cytoplasmic processes. We conclude that these tumors constitute parts of the broadening spectrum of neuroendocrine skin carcinomas that may derive from Merkel cells.     

Light and scanning electron microscopic and immunohistochemical studies on permeability of hypertensive rat mesenteric arteries

Experimental hypertensive rats were intravenously injected with carbon and iron as tracers, and their mesenteric arteries exhibiting hypertensive arterial lesions were observed by light and scanning electron microscopy and immunohistochemistry. Early arterial lesions showing intense medial damages, deposition of fibrinoid substance consisting of fibrin in the intima and/or media, and granulation tissue in the adventitia were characterized by marked insudation of intravenously injected tracers. Scanning electron microscopy demonstrated numerous leukocytes and platelets adhering to endothelial surface, opened endothelial cell junctions, and desquamation of these cells. Immunohistochemistry revealed laminin and low stainability of fibronectin in the subendothelium. Advanced lesions showed deposition of a large amount of fibrinoid substance and no insudation of tracers in the intima, but scanning electron microscopy manifested opening of endothelial cell junctions, desquamation of endothelial cells, and adherence of leukocytes and platelets. Immunohistochemistry revealed fibronectin in the intima and laminin just beneath the endothelium. In the healed lesions disclosing fibrocellular intimal thickening, there was no insudation of tracers. Scanning electron microscopy showed opened endothelial cell junctions, endothelial cell defects, and adherence of leukocytes and platelets. There were fibronectin in the intima and laminin beneath the endothelium. It was suggested that the opening of endothelial cells junctions and desquamation of endothelial cells would be necessary for the arterial increased permeability in hypertensive rats, and that fibrin-fibronectin complex, fibronectin-acid mucopolysaccharide complex, and basement membrane would together inhibit the increased permeability in the mesenteric arteries of hypertensive rats in spite of endothelial cell injuries and their defects.     

Hyaline globules in yolk sac tumor. Histochemical, immunohistochemical and electron microscopic studies

Four cases of yolk sac tumor of the testis and ovary were examined by histochemistry, immunohistochemistry, and electron microscopy, and particular attention was directed toward the close relationship between hyaline globules and alpha fetoprotein (AFP). The hyaline globules were easily identified as eosinophilic globular structures located in the cytoplasm of the tumor cell as well as in the extracellular space. They were considered to be of glycoprotein in nature by their histochemical staining property. By an indirect immunoperoxidase method, the majority of intracytoplasmic hyaline globules were positive for AFP. Electronmicroscopically, the hyaline globules appeared as electron dense bodies with no limiting membranes. They were divided into two types by their electron density and inner structure: one is an electron high dense body consisting of homogeneous or fine granular materials and the other is a moderately electron dense body composed of fine filamentous structures similar to the basement membrane materials. It is suggested that the former corresponds with the AFP positive hyaline globules produces by the tumor cells of visceral type, while the latter represents the AFP negative globules formed by the cells of parietal type in non-neoplastic counterparts.     

Epithelioid hemangioendothelioma of the anterior mediastinum with osteoclast-like giant cells. Light microscopic, immunohistochemical, and electron microscopic study

A case of epithelioid hemangioendothelioma of the anterior mediastinum in a 40-year-old woman is presented. It showed typical features described in such tumors, but in addition there were foci of osteoclast-like giant cells that were not previously reported in this lesion.     

Neurothekeoma. Report of a case with immunohistochemical and ultrastructural studies

A case of neurothekeoma in a 52-year-old woman is reported. The tumor developed on the medial aspect of the right nostril as a well-demarcated, dome-shaped, erythematous nodule of rubbery consistency. Microscopically, it consisted of numerous nests and cords of spindle-shaped cells in the dermis. Some of the tumor cell nests appeared epithelial-like, while the other areas showed a myxomatous appearence with various amount of mucinous matrix in the intercellular space. Neurothekeoma is a benign cutaneous tumor, and is considered to be of schwann cell origin. In the present case, the tumor cells did not stain positively for S-100 protein, despite the light microscopic suggestion of peripheral nerve origin. Ultrastructurally, most tumor cells contained a large number of myelinoid figures. This ultrastructural finding appears to be a useful diagnostic characteristics of neurothekeomas.     

The surface lining cells of cardiac myxoma. Light, electron microscopic and immunohistochemical observation

Morphological, enzymatic and electron microscopic studies have been performed on the surface covering cells of cardiac myxoma (CM) in 4 clinical cases. The superficial layer of CM is composed of mono- or poly-layers of polygonal cells and the superficial cells are connected with the tumor cells within CM. Electron microscopic picture showed many microvilli on the surface of the superficial cells, and the neighboring cells extend extrusions one to another connecting with desmosomes. Formation of incomplete basal membrane was observed in the underlying cells. These cells were morphologically similar to those of the tumor cells in CM. Polygonal superficial cells were shown by scanning electron microscope, and there was no consistent arrangement, which was different from the vascular endothelial cells. Factor VIII-related antigen was proved in the tumor cells having vascular like space in CM, suggesting differentiation of the tumor cells to the vascular endothelial cells. Factor VIII-related antigen was negative in the superficial covering cells. It may be said that the superficial covering cells of CM are premature tumor cells having no character as endothelial cells.