A juxtaglomerular cell tumour: light and electron microscopic studies of a renin-secreting kidney tumour containing both juxtaglomerular cells and mast cells

Codonopsis Radix modulates water and electrolytes homeostasis in mice

Codonopsis Radix is a traditional Chinese medicine best known for its effects in treating digestive, cardiovascular, immunological and hematopoitic diseases. It also appears in the traditional Chinese medical prescriptions against ascites. However, the physiological effect and molecular mechanism of Codonopsis Radix in water and electrolytes homeostasis have not been well studied. We found that Codonopsis Radix decoction increased water intake and the urine volume, but decreased food intake in mice. The treatment significantly reduced angiotensin II receptor (AT1R) transcription and serum aldosterone level in animals, suggested perturbed function of renin-angiotensin system. RNAseq analysis of Codonopsis Radix treated NCI–H295R cells detected suppressed AT1R, SP1, and TEF transcription as well. Thus, Codonopsis Radix may regulate water and electrolytes homeostasis by affecting AT1R expression and aldosterone biosynthesis, possibly through downregulating SP1 and TEF transcription.

Juxtaglomerular Cell Tumor of the Kidney

We present a case of juxtaglomerular cell tumor (JGCT) that developed in a 44-year-old woman with hypertension, which subsided after the tumor was removed. The tumor was 8.5 cm in greatest dimension and is thought to be the largest such tumor reported to date. Ultrastructural study confirmed the diagnosis of JGCT by the demonstration of the typical cytoplasmic rhomboidal secretory granules on electron microscopy. The tumor cells were also strongly reactive for CD34, a finding that has not been previously reported and that may be an adjunct to the diagnosis of JGCT in a patient with hypertension, hyperreninemia, and/or hypokalemia. At present, however, further studies on additional cases for CD34 expression will be necessary to fully evaluate the diagnostic utility of this marker in the diagnosing of JGCT.

Recurrent hypertensive cerebral hemorrhages in a boy caused by a reninoma: rare manifestations and distinctive electron microscopy findings

Recurrent cerebral hemorrhages caused by hypertension secondary to reninoma are extremely rare in children. Because of its detrimental effects on children's health, the importance of early diagnosis of and treatment for reninoma should be emphasized. Here, the authors present a 10-year-old boy with intermittent headaches and neurologic deficiency symptoms caused by hypertension. A reninoma in the right kidney was detected and successfully treated with laparoscopic partial nephrectomy. Two cell types were revealed in the tumor tissue under electron microscopy: renin secreting tumor cells and mast cells. This rare case expands our knowledge of hypertension in children and provides direct evidence that mast cells may infiltrate reninoma.

Juxtaglomerular cell tumor: a clinicopathologic study of four cases and review of the literature

We studied 4 new cases of juxtaglomerular cell tumor and compared their morphologic and immunohistochemicalfeatures with 2 renal hemangiopericytomas and 5 cutaneous glomus tumors. The juxtaglomerular tumors were resectedfrom 2 males and 2 females (mean age at diagnosis, 23 years). Three patients manifested with severe hypertension. Tumors ranged from 2.2 to 8.0 cm and were well circumscribed. The tumors consisted of solid sheets and nodules of variably sized tumor cells with round, oval, and spindled nuclei alternating with edematous microcystic foci. Nuclear atypia, present in all tumors, was a prominent feature in 2. Mitotic activity was not identified. All cases showed hemorrhage, numerous mast cells, and thick-walled blood vessels. Unusual features included coagulative tumor necrosis, a hemangiopericytoma-like vascular pattern, and hyalinized stroma. All tumors were immunoreactive for CD34 and actin. Ultrastructural analysis revealed the presence of rhomboid-shaped renin protogranules. Patients were treated by partial or radical nephrectomy and followed up for 14 to 48 months. There were no recurrences or metastases. The characteristic clinical and morphologic features of juxtaglomerular cell tumor permit distinction from renal hemangiopericytoma and other renal tumors.

Alveolar soft-part sarcoma: a review of the pathology and histogenesis

The descriptive designation, alveolar soft-part sarcoma, continues to be used for this uncommon soft-tissue malignancy because an acceptable hypothesis for its histogenesis has not been advanced, despite studies with electron microscopy and immunohistochemistry. These techniques have, nevertheless, provided significant information that is useful in the differential diagnosis of the tumor and pertinent in speculation concerning its nature. The most intriguing ultrastructural feature is the secretory process that culminates in the formation of the distinctive cytoplasmic crystals. Myogenic differentiation has been favored in a number of recent reports on the basis of immunohistochemical findings and the presence of the crystals does not rule out the possibility, but accounts of immunoreactivity for the myogenic regulatory protein MyoD1 have not been confirmed in subsequent studies or in the authors' own staining of six cases.

Juxtaglomerular cell tumor of the kidney: report of a non-functioning variant

A case of a juxtaglomerular cell tumor (JCT) in a 46-year-old man is reported. The tumor, 2.4 cm at its greatest dimension, was incidentally detected by ultrasonography. Although histological, immunohistochemical, and electron microscopic examinations revealed typical features of a JCT, the patient had no history of hypertension or hypokalemia. This is the first report of a non-functioning JCT in the literature.

Juxtaglomerular cell tumor of the kidney: report of two cases with a papillary pattern

We report the clinicopathologic, immunohistochemical, and electron microscopic study of two cases of juxtaglomerular cell tumor of the kidney with a hitherto unreported dominant papillary pattern. Both tumors were associated with high blood pressure that did not respond to medical therapy, but that returned to normal after removal of the kidney. They were well delineated, tan, and had no necrosis. The cores of the papillary structures consisted of polygonal cells found to express renin by immunohistochemistry and to contain renin protogranules by electron microscopy. The papillary fronds were covered by one layer of cuboidal epithelial cells that did not stain for renin and had ultrastructural features reminiscent of the collecting duct epithelium. These tumors must be differentiated from malignant papillary tumors of the kidney, such as papillary clear cell carcinoma, transitional cell carcinoma, and collecting duct carcinoma.

Juxtaglomerular cell tumor of the kidney. Morphological, immunohistochemical and ultrastructural studies of a new case

The authors describe a Juxtaglomerular Cell Tumor (JGCT) in a hypertensive young man whose symptomatology disappeared when the JGCT was removed. The clinical diagnosis was made before surgery by selective determination of plasma renin activity level in both renal veins and in the draining vein of the tumor. This neoplasm is benign and usually occurs in young patients. The morphological, immunocytochemical and ultrastructural features are described. Other renin-secreting tumors and the theories about histogenesis of JGCT are discussed.

Crystals in an oligodendroglioma: an optical, histochemical, and ultrastructural study

The report describes an oligodendroglioma that was examined in four biopsies and contained a large number of intracytoplasmic crystals. The crystals appeared in neoplastic cells with eosinophilic cytoplasms and eccentric nuclei. They were positive to periodic acid-Schiff stain and resistant to diastase. A lysosomal genesis of the crystals is proposed on the basis of a transition observed between lysosomal bodies with lipid droplets and those with crystalloid electron-dense structures. The morphologic and histochemical features of these crystals are compared to those in other tumors, lesions, and nonneoplastic cells.

Paracrystalline inclusions in metaplastic ciliated cells of the human gastric mucosa. An ultrastructural study

Unusual electron-dense paracrystalline inclusions were found in metaplastic ciliated cells in the stomachs of three Japanese male patients with gastric carcinoma. These patients had not been given antitumour drugs before surgery and ethrane (enflurane) was used as the anaesthetic. Ciliated cells in the gastric mucosa are found not infrequently in the pyloric glands in association with intestinal metaplasia in elderly Japanese patients. Paracrystalline inclusions were found only in the ciliated cells and never in any other types of gastric mucosal cell. These inclusions were located in the apical portion of the ciliated cells in intimate association with the basal bodies. They consisted of twisted strings about 27 nm wide with a regularly repeated spacing of about 30 nm. On highly magnified electron micrographs, granules about 4 nm in diameter were detected. These paracrystalline inclusions have never been reported previously, although their location in ciliated cells and their morphological characteristics suggest an intimate relationship with the ciliogenesis of metaplastic ciliated cells in the human stomach.

Intraluminal crystalloids in prostatic adenocarcinoma. Immunohistochemical, electron microscopic, and x-ray microanalytic studies

Histochemical, immunohistochemical, electron microscopic, and x-ray microanalytic studies were performed on crystalloids within glandular lumina of adenocarcinomas of the prostate. In a review of light microscopic sections of 343 prostatic adenocarcinomas, unequivocal crystalloids were identified in 35 cases (10.2%). Immunohistochemical and ultrastructural studies revealed distinct differences between these crystalloids and the Bence Jones crystals of multiple myeloma: anti-kappa and anti-lamda immunostaining was negative, and the characteristic lattice-like architecture of Bence Jones crystals was not seen. Differences from corpora amylacea also were demonstrated. X-ray microanalysis did not elucidate the nature of the prostatic crystalloids, and their biochemical composition and mode of formation remain uncertain. Detection of the crystalloids in light microscopic sections nevertheless can aid in the diagnosis of prostatic adenocarcinoma, particularly when the tissue is distorted by crushing artifact, or if the tumor is so well-differentiated that it can be confused with atypical hyperplasia or inflammatory atypia. When intraluminal crystalloids are detected in prostatic glands that appear histologically benign or atypical, study of additional levels or a repeat biopsy should be undertaken.

Anatomy of the renin-angiotensin system in the normal and pathological kidney

In this review we describe the contributions made by immunocytochemistry to our knowledge of the renin-angiotensin system in the normal and the pathological kidney. Most of the renin-secreting cells appear to be on the outer aspect of the vessel wall, supporting the view that renin is secreted mainly into the interstitium of the kidney rather than into the lumen of the vessel. Angiotensin II immunoreactivity is present within renin-secreting cells. The angiotensin II appears to be present in high concentration in the renin storage granules and is therefore presumably secreted from the cell with renin. The pathways by which renin is secreted from the cell have also been clarified. In pathological kidneys, the reactions of renin-secreting cells to variation in functional demand have been confirmed. Renin-containing cells have also been found in most types of renal tumours and occasional cases probably secrete renin or prorenin into the blood. In renal tumours and in the developing kidney (in all species studied) the renin-containing cells are also intimately associated with blood vessels.

Crystals and alpha-1-antitrypsin-reactive globoid inclusions in an islet cell tumor of the pancreas

An islet cell tumor of the pancreas with unusual light microscopic, ultrastructural, and immunocytochemical features is reported. In addition to secretory granules and positive immunostaining for pancreatic polypeptide, the tumor contained globoid intracytoplasmic inclusions by light and electron microscopy, which correlated with a positive immunoreaction for alpha-1-antitrypsin, and Reinke-like crystals.

Renin storage and cell differentiation in juxtaglomerular cell tumors: an immunohistochemical and ultrastructural study of three cases

Three renin-secreting juxtaglomerular cell tumors were studied by ultrastructural and immunocytochemical methods. Both active and inactive renins were identified in tumor extracts. By immunofluorescence and the peroxidase-antiperoxidase (PAP) method with antirenin antiserum, immunolabeling was intracytoplasmic and irregularly distributed throughout the tumor tissue. Electron microscopic examination revealed various types of secretory granules, including atypical giant crystalloid protogranules in one case, and the postembedding PAP procedure showed labeling of all types of granules. Acid phosphatase staining was observed within secretory granules and autophagic vacuoles. The process of renin storage and release is discussed. The presence in one case of a neural component and a distal tubular structure supports the view of a hamartomatous lesion.

Juxtaglomerular cell tumor of the kidney

The authors describe a juxtaglomerular cell tumor (JGCT) which caused severe hypertension in a 58-year-old man. Light microscopy showed a circumscribed tumor composed of interlacing cords and occasional nodules of relatively uniform cells with no mitotic activity. Rhomboid crystals characteristic of "prerenin" were present within the cytoplasm of tumor cells, and there was a close relationship between the tumor and unmyelinated nerve axons. Intracytoplasmic renin was demonstrated by immunofluorescence, and tumor granules were shown to contain zinc by electron-beam microanalysis. Review of 14 prior cases, with additional follow-up of 9, showed that no patient had developed recurrence, metastasis, or another tumor. Four patients, however, are hypertensive but probably because of secondary tumor effects rather than recurrent hyperreninism. The distinction of JGCT from hemangiopericytoma with renal involvement is important because of the high mortality associated with the latter. The authors conclude that JGCT is benign, but patients with JGCT may remain hypertensive postnephrectomy because of hypertensive angiopathy.

Malakoplakia and malakoplakialike lesions of the upper gastrointestinal tract

This report describes the clinical and pathologic features of 3 cases of unusual lesions that bear a striking similarity to malakoplakia. The lesions were located in the stomach, submental region, and oropharyngeal soft tissues. The cellular infiltrates were composed of sheets of mononuclear cells with abundant, granular, eosinophilic cytoplasm. Nuclei were small and bland, and mitoses were extremely rare. Lymphocytes and plasma cells were present in varying numbers. Ultrastructural studies revealed unusual crystalline structures within dilated cisternae of rough surfaced endoplasmic reticulum of plasmacytoid cells in all 3 cases. The 3 cases may represent a morphologic spectrum of chronic immunologic stimulation, with the crystalline structures limited to stimulated lymphocytes of gastrointestinal tract lesions.

Crystals in a gastric schwannoma

A gastric schwannoma containing large numbers of intracytoplasmic crystals is described. The latter are compared with intracytoplasmic crystals found in the cells of other tumors and their nonneoplastic cell counterparts. The extreme morphologic and histochemical heterogeneity of the different types of crystals is emphasized.

Electron microscopy in surgical pathology: a selective review

The high resolution provided by electron microscopy can contribute to histomorphological diagnosis by allowing the detection of structures which are invisible to the light microscope. These structures include characteristic nuclear or cytoplasmic contours, intercellular attachments and intracellular components. The recognition of such features may allow specific diagnosis in lesions which cannot be precisely categorized by light microscopy. Electron microscopy is particularly useful for the diagnosis of neoplasms. This review describes some of the characteristic morphological features which can be demonstrated in neoplastic cells by electron microscopy and briefly considers several areas where the technique is of special value. Electron microscopy is now an integral part of the diagnostic process in surgical pathology and can be regarded as a routine technique rather than a special procedure to be delegated to others.

Hypertension due to a renin-secreting tumour localised by segmental renal vein sampling

An 18-year-old female was found to be hypertensive on routine medical examination. Further investigation disclosed persistent hypokalaemia and elevated plasma renin activity in peripheral venous blood. Segmental renal vein sampling with assay of blood samples located the source of excess renin secretion in the lower mid-zone of the left kidney. This localization was not confirmed by either angiography or by palpation of the exposed kidney before nephrectomy but macroscopic examination of the freshly sectioned kidney revealed a small tumour in the region suggested by renal vein sampling. The tumour had the morphologic pattern fo an haemangiopericytoma with abundant ultrastructural specific granules and very high renin activity by tissue assay. Plasma renin activity fell precipitously after nephrectomy and remained very low for the first week. Although the immediate post-operative blood pressure fell to normal, hypertension recurred temporarily and was associated with elevated plasma aldosteron, producing a syndrome similar to primary aldosteronism. All variables returned to normal without specific therapy and hypertension has not subsequently recurred.

Extrarenal renin-secreting tumor associated with hypertension

Described herein is an autopsy case of a 16-year-old female with severe hypertension, hyperreninemia and secondary aldosteronism. She had had a progressively growing tumor of her right orbita from the age of 4. The tumor was partially excised 13 months before death. A high content of a renin-like material was detected in the excised tumor, which was histologically a hemangiopericytoma. Bowie stain revealed some granules in small number of tumor cells and electron microscopic study showed some cytoplasmic granules. Following the operation, hypertension was somewhat improved, but the levels of plasma renin activity and plasma aldosterone concentration remained elevated, because the tumor was partially resected. At autopsy, the tumor invaded into the cranial base and right frontal lobe, and metastasized to the lungs. In the present case, renal renin-secreting tumor, malignant hypertension and renovascular hypertension were ruled out by the clinical and pathological studies.

Big renin: identification, chemical properties and clinical implications

Big renin has a greater molecular weight (63,000 versus 43,000) than normal renin, but it shares the characteristic enzymatic and immunologic properties of normal renin. As it exists in the kidney or plasma of a patient, big renin is less active than normal renin, but its enzymatic activity is greatly enhanced by exposure to pH values of 3.0 to 3.6 or by brief incubation with pepsin or trypsin. Use of the terms prorenin and zymogen might be withheld until big renin is shown to exist in normal tissue or plasma and to be converted to normal renin in vivo. To date, big renin has been found in renal tumors and other abnormal kidney tissues as well as in the plasma of patients with renal disorders. The remarkable activation of big renin at pH levels of 3.3 can be used to detect its presence. If a method involving acidification is used to quantitate plasma renin activity of a patient with circulating big renin, the activated plasma renin activity greatly exceeds that measured in plasma maintained at neutral pH. Gel filtration of plasma is used to prove the presence of big renin. When large amounts of big renin are secreted by a renal tumor, hyperfusion may ensue and be cured by removal of the tumor. The secretion of small amounts of big renin does not necessarily result in any physiologic disorder. However, if there is a concomitant diminution or absence of normal renin a state of apparent hyporeninemia exists, as we have observed in diabetic nephropathy; this may be associated with hypoaldosteronism and hyperkalemia. Big renin does not appear to respond to physiologic changes that stimulate or suppress normal plasma renin activity. The finding of big renin may indicate the presence of certain renin-secreting renal tumors or other renal disorders, especially diabetic nephropathy.