Victor E. Gould

Lack of CD 29 (β1 integrin) and CD 54 (ICAM-1) adhesion molecules in intravascular lymphomatosis*

Intravascular Lymphomatosis (IL) is a rare and usually aggressive form of non-Hodgkins lymphoma characterized by the growth of neoplastic cells within vascular lumina that usually presents with skin or central nervous system (CNS) involvement. The mechanism(s) for the selective intravascular growth of this neoplasm remain(s) unexplained. We now report clinical and immunohistologic data on surgical material from 6 cases of IL; in 4 of 6 cases, autopsies were performed. Our IL cases shared the following features: (1) B-cell lineage; (2) lack of skin involvement at presentation; (3) aggressive behavior; and (4) lack of extravascular lymphomatous masses; in addition, 1 case had an associated gastric low-grade MALT lymphoma. We studied by immunohistochemistry formalin-fixed, paraffin-embedded sections with monoclonal antibodies to molecules known to be involved in lymphocyte and endothelial adhesion phenomena, that is, CD29 (beta1 integrin subunit), CD43 (leukosialin), CD44 (H-CAM), CD54 (ICAM-1), embryonal N-CAM (e-NCAM), and EMA (episialin). In all cases, the surfaces of IL aggregates reacted for CD44 but were consistently negative for CD29; also absent was CD54. Conversely, the integrity of the endothelial cells was underscored by their even reactivity for CD29, CD44, and CD54. Given that CD29 is currently regarded as critical for lymphocyte trafficking in general and for transvascular migration in particular, and CD54 is also involved in transvascular lymphocyte migration, we conclude that their consistent absence in IL may contribute to its intravascular and disseminated distribution pattern. The rather frequent association of IL with various conventional lymphomas is known; yet, one of our cases appears to be the first report of IL associated with a low-grade MALT lymphoma.

Immunohistochemical and ultrastructural analysis of bronchopulmonary neuroendocrine neoplasms. I. Carcinoids

Twenty-five strictly defined bronchopulmonary carcinoids were studied by light microscopic immunohistochemistry by the peroxidase technique for NSE (neuron-specific enolase), serotonin, and a broad spectrum of neuropeptides. Eighteen cases were also studied by electron microscopy. Twenty-three of the twenty-five cases showed immunostaining for NSE; 24 cases displayed immunostaining for at least two of the hormones tested for; the single case that failed to show hormonal immuno-reactivity was however positive for NSE and had granules by electron microscopy. Serotonin was the most frequently demonstrated hormone followed by bombesin, vasoactive intestinal peptide, gastrin, leu-enkephalin , alpha-melanocyte stimulating hormone, somatostatin, substance P, and calcitonin. In several cases, adjacent-step sections stained for different hormones strongly indicated immunoreactivity for more than one hormone in single neoplastic cells. By electron microscopy, all 18 cases studied showed generally abundant neurosecretory granules, which, however, displayed considerable heterogeneity in their size, shape, and density. Twelve of these eighteen cases displayed evidence of squamous differentiation and 10 showed characteristic exocrine lumina. The capability of single neuroendocrine tumors and single neuroendocrine tumor cells to produce more than one immunoreactive hormone is hereby amply confirmed; these broad capabilities are certainly reflected in the heterogeneous granule populations seen by electron microscopy. The synchronous presence of squamous and exocrine features in broncho-pulmonary carcinoids indicates that they too are capable of multidirectional differentiation, which should not detract from their being regarded basically as well-differentiated neuroendocrine neoplasms. The clinical significance of strictly defining bronchial carcinoids is underscored by the fact that of 25 cases followed for 2-13 years, only one developed metastases 9 years postoperatively.

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.

Malignant gastric neuroendocrinomas: Ultrastructural and biochemical characterization of their secretory activity

Abstract In two cases of malignant gastric tumors originally diagnosed as undifferentiated carcinomas electron microscopy revealed a neurosecretory type of granule. Subsequently tumor extracts were tested by biochemical methods and shown to have vanillylmandelic acid and 5-hydroxy-3-indoleacetic acid activity. Neither patient had signs or symptoms referable to the presence of these or related substances. These observations parallel those made in a variety of neuroendocrine tumors in which demonstration of neurosecretory granules or isolation of amine or peptide materials or their metabolites has not necessarily been reflected in clinical hormonal syndromes. Our findings indicate that regardless of clinically apparent hormonal activity or lack thereof, some undifferentiated gastric carcinomas may in fact derive from neuroendocrine APUD elements.

Neuroendocrine carcinomas of the colon. Ultrastructural and biochemical evidence of their secretory function.

Four cases of malignant colonic tumors diagnosed by light microscopy as “small cell undifferentiated carcinomas” were shown by electron microscopy to have neurosecretory-type granules. Biochemical analysis of tumor tissue extracts disclosed the presence of considerable levels of VM A and catecholamines in all tumors; 5-HIAA was present in one tumor. Clinically, there had been no signs or symptoms attributable to those or related substances.Similar observations have been reported in a variety of neuroendocrine neoplasms; for example, the demonstration of neurosecretory-type granules and determination of amine or peptide materials in tumor tissue or body fluids may not be necessarily reflected in clinical hormonal syndromes or obvious metabolic abnormalities.Our structural and biochemical observations indicate that, regardless of clinically evident hormonal activity or lack thereof, some small cell “undifferentiated” colonic cancers derive from APUD elements, and therefore they should be classified within the group of neuroendocrine carcinomas. The evident secretory capabilities of these carcinomas suggest obvious diagnostic possibilities and could conceivably lead to a reappraisal of current therapy.

Medullary Carcinoma of the Thyroid Gland: An Immunocytochemical Study

Twenty-seven cases of medullary carcinoma of the thyroid gland (MCT) were studied by light microscopy, immunocytochemistry, and electron microscopy. Immunoreactivity for neuron-specific enolase (NSE) and calcitonin was present in all tumors. The numbers of peptides and serotonin demonstrated in each case varied from one to eight. Bombesin was present in 18 of the 27 cases, serotonin in 15, leu-enkephalin in 8, somatostatin in 8, gastrin in 3, substance P in 1, vasoactive intestinal peptide (VIP) in 1, and ACTH in 1. Insulin and glucagon were not encountered in any of the tumors. Immunoreactivity for thyroglobulin was seen in five primary tumors as well as in one lymph node metastasis. The finding of concurrent production of calcitonin and thyroglobulin within the same tumor is enough to question the dogma of the separate origin of follicular cells and C-cells. We were unable to attach any clinical importance to the production of multiple peptides and/or amines.

Increased numbers of cytokeratin-positive interstitial reticulum cells (CIRC) in reactive, inflammatory and neoplastic lymphadenopathies: hyperplasia or induced expression?

A total of 291 enlarged lymph nodes showing a range of reactive-inflammatory processes, primary and metastatic neoplasms were studied to determine the distribution and immunoprofile of their cytokeratin-positive interstitial reticulum cells (CIRC) in comparison with normal nodes. In 258/291 nodes (89%), CIRC numbers were distinctly increased in the subcapsular, paracortical and, occasionally, in the medullary zones; often, these increased CIRC formed networks around follicles, sinuses and vessels. CIRC had comparatively small, irregularly shaped bodies and dendritic processes; occasionally, giant forms were noted. CIRC contained cytokeratins (CK) 8 and 18 but not 19, as shown by immunohistochemistry, and by gel electrophoresis with subsequent immunoblotting. They co-expressed vimentin consistently, alpha-smooth-muscle actin frequently, and desmin less frequently. They did not contain desmoplakins, Factor VIII, S-100, LCA, B and T lymphocyte- and macrophage-associated antigens, chromogranin A, synaptophysin or the A-80 glycoprotein. We found no clear correlation between the increased CIRC and given nodal disease processes. However, CIRC were most abundant in nodes free of but draining malignant tumours; bizarre CIRC assemblies were noted in HIV lymphadenopathy. CIRC appear to represent a subset of the so-called “fibroblastic reticulum cells” of lymph nodes. Their function remains undetermined; their increase in diverse lymphadenopathies suggests that they partake in nodal reactions to injury. It remains unclear whether the increase in CIRC relative number is due to proliferation or to CK gene induction processes but their presence and potential capability to undergo hyperplasia with dysplastic forms should alert pathologists to possible diagnostic pitfalls. In addition, we discuss that CIRC may undergo transformation and represent the “cell of origin” of certain CK-positive tumours restricted to lymph nodes.

Glial FibriUary Acidic Protein (GFAP) Immunoreactivity in Peripheral Nerve Sheath Tumors

A spectrum of 24 benign and malignant nerve sheath tumors and 10 non-neural spindle-cell tumors were studied by iight microscopy for the presence of glial fibrillary acidic protein (GFAP) immunoreactivity by the peroxidase-antiperoxidase (PAP) technique. In 8 cases, these results were compared to their electron mocroscopic appearances. Seventy percent (7 of 10) of begnine schwannomas and 50% (4 of 8) of benign neurofibromas demonstrated focal to diffuse GFAP immunoreactivity. None of the malignant nerve sheath tumors nor any of the non-neural spindle-cell neoplasms contained demonstrable GFAP immunoreactivity. Similarly, no GFAP immunoreactivity could be detected in Schwann cells in normal peripheral nerves. The solitary benign schwannoma available for electron microscopic study demonstrated diffuse and abundant cytoplasmic intermediate filaments, and this tumor displayed diffuse and intense GFAP immunoreactivity. Two benign neurofibromas showed a more variable content of intermediate filaments ultrastruc...

Synaptophysin: A new marker for pancreatic neuroendocrine tumors

Synaptophysin (SYP) is a glycoprotein recently isolated from presynaptic vesicles of bovine neurons. Initial studies have demonstrated its presence in neurons in the brain, spinal cord and retina, and in adrenal medullary cells. A subsequent study demonstrated it in pancreatic islet cells and certain neuroendocrine (NE) neoplasms, including several pancreatic islet cell tumors. Based on these preliminary observations, we examined, by immunohistochemistry, conventionally fixed, paraffin sections of 57 pancreatic endocrine tumors with a monoclonal antibody to SYP. Furthermore, we compared the SYP immunoreactivity of 30 of these same tumors with that of neuron-specific enolase (NSE) and of chromogranin (CG). SYP was demonstrated in all but one of the 57 tumors. In the comparative study, for which material was available in only 30 cases, SYP and NSE were present in 29 of the tumors, whereas CG was seen in only 15 cases. We conclude that SYP is a highly sensitive and useful marker for pancreatic NE neoplasms. Moreover, in view of the increasingly evident limited specificity of NSE, SYP should be considered the marker of choice for pancreatic NE neoplasms.

Extracellular matrix proteins and their receptors in the normal, hyperplastic and neoplastic breast.

We studied by immunohistochemistry, the distribution of tenascin (Ten), cellular fibronectin (cFn), laminin and certain pertinent extracellular matrix protein receptors in normal human female breast, variants of fibrocystic disease (FCD), benign tumors, and ductal and lobular carcinomas. Monoclonal antibodies (mAb) to Ten, extradomain A containing cFn (EDAcFn), A and B chains of laminin, and beta-1 (beta-1) and different alpha subunits of intergrins were used. In in-situ ductal and lobular carcinomas, laminin staining had focal gaps, Ten-immunoreactivity displayed periductal or periacinar bands, and cFn showed broad and intense periductal staining; strong reactions for beta-1 and alpha-6 were noted in the basal cytoplasm of non-neoplastic myoepithelial cells while few tumor cells stained weakly. In infiltrating ductal and lobular carcinomas (IDC, ILC), laminin reactivity was weak, uneven or absent around neoplastic clusters whereas stromal staining for Ten and cFn was extensive and strong. In most IDC, moderate beta-1 and alpha-6 staining involved variable subpopulations; one mucinous carcinoma stained strongly and diffusely. In 20-40% of cells in ILC, beta-1 and alpha-6 were localized in delicate, ramified cytoplasmic processes. Indirect immunofluorescence studies with mAbs to other alpha-integrin subunits suggest that in various breast carcinomas only alpha-3 is expressed in tumor cells and that the vessels contained alpha-1 integrin. As compared with the normal breast, FCD and benign tumors, reactivity for Ten and cFn is increased in breast carcinomas while laminin is attenuated and decreased or absent; yet, Ten cannot be regarded as a carcinoma marker since it can be detected in benign tumors, FCD, and even in the normal breast.(ABSTRACT TRUNCATED AT 250 WORDS)