Differentiation, histogenesis and morphogenesis: their implications for tumor diagnosis.

Differentiation, as employed in tumor classification for histopathology, refers to the resemblance of neoplastic cells to their presumed cell/tissue of origin. Since differentiation for diagnosis is obtained by analysing histological images, this histogenetic concept creates practical limitations. Morphogenesis, a variant of differentiation, is a wider concept since it takes into consideration the nature of the tumor cells, their organization and their synthetic products. Consequently, morphogenesis, rather than differentiation, seems to be a better predictor of histogenesis in tumor diagnosis.

Existence of junction-like structures in large B-cell non-Hodgkin's lymphomas. An ultrastructural study.

The purpose of this work is to study the presence of cell junction-like structures in large B-cell lymphomas. The ultrastructural study, based on 20 cases of this entity proved by immunohistochemistry and flow cytometry, demonstrated four types of junction-like devices easily found between tumor cells. Several explanations are offered about the possible nature of such structures, including the possibility of them being the result of adhesion phenomena. It should also be emphasized that they can potentially complicate the differential diagnosis of those neoplasms. We should, therefore, be careful in rejecting an ultrastructural diagnosis of large B-cell lymphoma based only on the presence of junction-like structures.

Metastatic meningioma detected in pleural fluid.

Meningiomas with both malignant cytologic features and clinical behavior are rare. A 39-yr-old man with recurrent meningioma developed a pleural effusion which, on cytologic examination, contained metastatic meningioma. The diagnosis was subsequently confirmed histologically and ultrastructurally. In conclusion, metastatic meningiomas can retain meningotheliomatous cytologic features which may allow a diagnosis to be made of clinically unanticipated tumor spread.

Fine needle aspiration biopsy of a small round cell tumor exhibiting both neural and myogenic differentiation. A case report.

BACKGROUND: Divergent differentiation may not be detected in the limited material available in a fine needle aspiration biopsy (FNAB). CASE: A small round cell malignancy showed neural features ultrastructurally on FNAB, in keeping with primitive neuroectodermal tumor, but desmin and actin positivity on surgical biopsy, suggesting rhabdomyosarcoma. CONCLUSION: Accurate classification of small round cell tumors by FNAB is more likely to occur when both electron microscopy and immunocytochemistry are employed since these tumors may express divergent differentiation.

Adult colloid milium of the eyelid.

PURPOSE: To report a patient with bilateral upper and lower eyelid margin nodules that proved to be adult colloid milium. METHODS: After clinical study, biopsy specimens were obtained and analyzed histologically and ultrastructurally. RESULTS: Adult colloid milium can be diagnosed by clinicopathologic correlation. CONCLUSION: Adult colloid milium should be included in the differential diagnosis of eyelid margin nodules.

Contribution of transmission electron microscopy to fine-needle aspiration biopsy diagnosis: comparison of cytology and combined cytology and transmission electron microscopy with final histological diagnosis.

This report evaluates 74 fine-needle aspiration biopsies processed for transmission electron microscopy with subsequent surgical procedure. The specificity of diagnosis obtained by cytology alone was compared to that obtained by cytology and electro microscopy, using histologic diagnosis as the gold standard. When cytology gave a diagnosis of malignancy but could not give tumor category or type, electron microscopy could correctly give both. When cytology could give tumor category but not type, electron microscopy correctly identified type in the majority of cases. When cytology gave tumor category and type, electron microscopy confirmed the diagnosis. Transmission electron microscopy is very helpful when the cytopathologist can diagnose malignancy but cannot give tumor category and/or type. When the cytopathologist is specific in his/her diagnosis, TEM is not as helpful.

Fine needle aspiration biopsy diagnosis of a gastrointestinal stromal tumor utilizing transmission electron microscopy.

BACKGROUND: Gastrointestinal stromal tumors are spindle cell tumors with no specific cell lineage occurring in the gastrointestinal tract and cytologically resemble other benign and malignant spindle cell tumors. Distinctive ultrastructural features in some of these tumors have not been previously emphasized. CASE: A 76-year-old, white female presented with multiple tumor masses distributed in the large bowel. Fine needle aspiration biopsy demonstrated a cellular aspirate composed of spindle cells, some of which were loosely arrayed and some of which were in cohesive clusters. Many of the cells contained long cytoplasmic processes. Ultrastructurally the cells demonstrated long cytoplasmic processes upon which multiple shorter, fingerlike projections arose. Subsequent surgical resection confirmed the cytologic and ultrastructural findings. CONCLUSION: Electron microscopy has a role to play in the diagnosis of gastrointestinal stromal tumors.

Interleukin-1 beta in the dorsal vagal complex inhibits TRH analogue-induced stimulation of gastric contractility.

The effect of murine interleukin-1 beta (mIL-1 beta) microinjected into the dorsal vagal complex (DVC) on thyrotropin-releasing hormone (TRH) analogue (RX-77368)-induced stimulation of gastric contractility was examined in fasted, urethan-anesthetized rats. Gastric corpus contractions were measured with extraluminal force transducers and analyzed by computer. Microinjection of RX-77368 (30 ng) into the right DVC with mIL-1 beta microinjected either into the right (100, 250 pg) or into the left (100, 500 pg) DVC inhibited gastric contractility for 30-120 min postinjection. Peak suppression of gastric contractility (64-78%) occurred at 50-60 min postinjection. Microinjection of mIL-1 beta into the DVC at a lower dose (10 pg) or into sites adjacent to the DVC (100-500 pg) did not suppress the stimulated gastric contractility pattern. Injection of mIL-1 beta (250 pg) or 0.1% bovine serum albumin into the DVC alone did not alter basal gastric contractility. Intracisternal injection of the IL-1 receptor antagonist (250 ng/10 microliters) abolished the inhibitory effect of mIL-1 beta (250 pg) on gastric contractility. These results demonstrate that mIL-1 beta acts in the DVC to inhibit vagally stimulated gastric contractility, and its action is mediated by IL-1 receptors.

[Hereditary nonpolyposis colorectal cancer. Lynch syndrome]. / Cáncer colorrectal hereditario sin poliposis. Síndrome de Lynch.

BACKGROUND: Hereditary non-polyposis colorectal cancer represent 5% of the colorectal cancer population. It's characterized by an autosomal dominant inheritance; there are two variants: Lynch syndrome I is characterized by predisposition to early onset colorectal cancer, with predominance for proximal location to the splenic flexure and synchronous and/or metachronous colorectal cancers. Lynch syndrome II shares the same features, but shows association with extracolonic cancers, particularly carcinomas of endometrium, ovary and stomach. However, this syndrome is not easily recognized, due to the lack of phenotypical expression as familiar adenomatous polyposis. OBJECTIVE: The purpose of this report is to review the natural history, diagnosis, treatment, surveillance of the probands and their families, and to update recent research on the genotypic risk biomarkers located in chromosomes 2, 3 and 7. METHODS: We analyzed the available literature to discuss the clinical characteristics, pathology, genetics, management, and surveillance of hereditary non-polyposis colorectal cancer. CONCLUSIONS: The diagnosis of hereditary non-polyposis colorectal carcinoma is not a rare event. It requires the demonstration of vertical transmission, therefore, the past history of colorectal cancer in the proband and his family should be carefully taken; including the anatomic site, histology and age at diagnosis.

Testicular juvenile capillary hemangioma: conservative management with frozen-section examination. A case report.

Juvenile capillary hemangioma, an exceptionally rare benign neoplasm, seen in an 18-year-old patient, was managed in an unorthodox fashion. The patient insisted on a conservative approach to the management of his tumour. In an effort to comply with his wishes, frozen-section examination of the tumour was carried out. The astute observations of the pathologist who recognized the juvenile capillary hemangioma made possible a conservative surgical excision and testicular repair. The case illustrates some of the difficulties that may be encountered in the successful management of testicular tumours.

Familial nephropathic systemic amyloidosis caused by apolipoprotein AI variant Arg26.

A point mutation in the apolipoprotein AI (apoAI) gene causing autosomal dominant non-neuropathic systemic amyloidosis is described in a previously unreported Canadian family of British origin with five affected individuals in three generations. Amyloid deposits in the renal biopsy from the proband, a 31-year-old female presenting with hypertension and renal failure, stained immunospecifically with antiserum to apoAI. The plasma of all family members with amyloidosis contained both wild-type apoAI and a variant bearing one additional positive charge. Sequencing of the apoAI gene demonstrated that the proband was a heterozygote for a single base substitution in exon 3, changing codon 26 from GGC(Gly) to CGC(Arg). Concordance of the mutant allele with the presence of variant plasma apoAI and clinical features of amyloidosis was demonstrated. This is the third family in which this amyloidotic mutation has been described, but the distribution of amyloid deposits and their clinical effects are clearly determined by other genetic and/or environmental factors.

Processing fine needle aspiration biopsies for electron microscopic examination. Experience implementing a procedure.

While processing needle rinses from fine needle aspiration biopsy material for electron microscopy, we experienced difficulties not fully outlined previously. Problems in preservation were traced to the time elapsed before glutaraldehyde was added to the needle rinse, which had been held in a physiologic transport medium; a tendency toward hypotonicity of the commercially prepared transport medium; and vigorous handling of the needle rinse. When these problems were dealt with, preservation improved dramatically. The problem of scanty material available for ultrastructural evaluation was dealt with by decreasing the number of smears made and filtering the needle rinse to capture tissue fragments. Implementation of the procedure required leadership, good communication, motivated cytotechnologists and cytopathologists, and continuous supervision and monitoring. In cases with adequately cellular well-preserved material available for electron microscopy, ultrastructural evaluation made a contribution of clinical value to the diagnosis in 48% of cases.

Intracytoplasmic lumina in squamous epithelial lesions of the oral cavity.

Intracytoplasmic lumina are considered a diagnostic feature of adenocarcinomas and have not been reported in squamous cell carcinomas. We are documenting intracytoplasmic lumina in a case of primary squamous cell carcinoma of the oral mucosa and in the oral squamous mucosa in two cases of graft versus host disease, confirming that intracytoplasmic lumina are also present in squamous epithelia and their tumors. Likely explanations for the presence of intracytoplasmic lumina in non-neoplastic and malignant squamous cells of the oral cavity include multiple differentiation, phagocytosis and immune attack on desmosomes.

Fine-needle aspiration biopsies of metastatic neuroendocrine tumors in liver: use of transmission electron microscopy and protein A gold technique in diagnosis.

Five fine-needle aspiration biopsies of liver were studied to evaluate the use of electron microscopy and protein A gold technique in the diagnosis of metastatic neuroendocrine tumors. All five cases had cytologic features suggestive of neuroendocrine tumors and neurosecretory granules on ultrastructural examination. The aspirates were stained by the immunoperoxidase technique and the postembedding protein A gold technique using the antibody to chromogranin A. Three cases were positive for chromogranin A by both immunoperoxidase and protein A gold techniques. Two cases were positive by protein A gold technique and negative by immunoperoxidase technique. Confirmation of neurosecretory granules by immunochemistry is ideal, since ultrastructurally they can be mimicked by other electron-dense inclusions. Advantage of the protein A gold technique is the use of the same material for both ultrastructural evaluation and the protein A gold technique.

Inflammatory pseudotumor of the spleen. Morphological, radiological, immunophenotypic, and ultrastructural features.

A case of inflammatory pseudotumor of the spleen is described. Its rapid enlargement, demonstrable by ultrasound studies and computed tomographic scan, its gross appearance, and some of its histologic features suggested malignant lymphoma. However, a characteristic circumferential zonal pattern and polytypic immunophenotype helped to establish the correct diagnosis. In retrospect, the zonal pattern was also identified radiologically.

Langerhans cell histiocytosis in monozygotic twins.

Langerhans cells histiocytosis, one of a group of histiocytosis syndromes characterized by Langerhans cell infiltration, has many clinical manifestations. In the past 30 years, numerous cases of presumed Letterer-Siwe disease, the acute multiorgan variant, have been reported in twins and siblings. Only recently has the Histiocyte Society established a criterion for a "definitive diagnosis" of Langerhans cell histiocytosis--the presence of Birbeck granules within the cells of the histiocytic infiltrate. We report the fatal outcome of Langerhans cell histiocytosis in monozygotic twin infants. There is no satisfactory explanation why Langerhans cell histiocytosis occurs concurrently in twins. We suggest that cytokines may provide an endogenous signal that triggers the pathologic proliferation of Langerhans cells.

Angiosarcoma of the uterus: a case report.

We are reporting a case of angiosarcoma of the uterus in which the diagnosis was confirmed ultrastructurally by demonstration of Weibel-Palade bodies in the tumor cells. Only 10 cases of this entity have been previously documented in the literature.

A carcinoid tumor of the stomach with features of a midgut tumor.

This report is, to our knowledge, the first of a gastric carcinoid tumor that, by electron microscopy, revealed pleomorphic neurosecretory granules similar to those found in carcinoid tumors arising from the midgut. On the basis of silver staining, this lesion would be classified as an argentaffin and argyrophil carcinoid tumor, of the type usually associated with midgut derivation. Immunostaining showed the presence of serotonin granules, and there was clinical evidence of intraoperative hyperserotoninemia. The lesion is believed to have arisen from foci of complete intestinal metaplasia, many of which were present in proximity to the site of the lesion and elsewhere in the stomach.