Aquaporin-1 expression in fluoro-edenite-induced mesothelioma effusions: An approach by cell-block procedure.

OBJECTIVE: Aquaporin 1 (AQP-1) is a water channel protein found in cell membranes, whose expression has been considered an independent favourable prognostic factor in pleural malignant mesothelioma (MM). The aim of this study was to evaluate the expression of AQP-1 and its prognostic value in a series of pleural MM effusions, from a geographical area with high concentrations of fluoro-edenite (FE). METHODS: We selected 25 MM cases from Biancavilla (Italy), an area with high environmental concentrations of FE. Cytological samples, cell-blocks (CB), clinical and follow-up data were available for all cases. Immunohistochemistry for calretinin, CK5/6, WT1, CK7 and TTF1 was used on CB sections to confirm the cytological diagnosis of MM. Immunohistochemistry for AQP-1 was performed and high expression was defined when ≥50% of tumour cells showed linear and circumferential membranous staining. RESULTS: The cohort included 16 men and nine women (median age: 67.5 years; range: 49-88 years). The median survival was 14 months (range 1.5-60 months), with a significant value (P = 0.006). All cases have been histologically confirmed and classified as epithelioid (16 cases), biphasic (seven cases) and sarcomatoid (two cases). AQP-1 high expression has been observed in 16 cases. Comparing AQP-1 high expression to the survival of corresponding patients, a significant association with a slight increased overall survival of 12 months has been demonstrated. Nine patients with a AQP-1 score less than 50% showed a shorter median overall survival (7 months). CONCLUSIONS: AQP-1 high expression is detectable on cytological samples of FE-induced MM with a prognostic value.

Fine needle aspiration cytology of lymphoproliferative lesions of the oral cavity.

OBJECTIVE: Oral cavity non-Hodgkin lymphoma (OCL) is a rare condition that may be clinically and radiologically indistinguishable from other pathologies of the mouth. A complete excision or adequate biopsy of the OCL may be difficult. Fine needle aspiration (FNA) cytology has been successfully utilized in the pre-operative diagnosis of oral masses and in lymphoma involving other anatomical areas. Our experience with FNA pre-operative cytological diagnosis of 16 OCLs is reported herein. METHODS: The results of FNA cytology on 16 consecutive lymphoproliferative lesions of the oral cavity collected over an 8-year period in three institutions were retrieved. Sampled lesions were submucosal masses of different sizes bulging into the oral cavity. Rapid on-site evaluation (ROSE) and routine cytological staining were performed. Immunocytochemistry (ICC), flow cytometry (FC) and polymerase chain reaction (PCR) of the IGH (immunoglobulin heavy) locus were performed on additional passes according to ROSE. RESULTS: Fourteen OCLs, one myeloma and one florid reactive lymphoid hyperplasia (FRLH) were diagnosed by FNA. OCLs were diagnosed as large B-cell (eight cases) and small B-cell (six cases) lymphomas. Histology revealed eight diffuse large B-cell lymphomas (DLBCL), four lymphomas of mucosa-associated lymphoid tissue (MALT), two follicular lymphomas and one FRLH; no false-negative or false-positive results were diagnosed, but accurate subclassification was obtained in four cases only. CONCLUSIONS: FNA diagnosis of OCLs may be hampered by the rare incidence, anatomical context and difficulties in obtaining a sufficient amount of cells. Ancillary techniques should be used according to ROSE; a pre-operative FNA cytology diagnosis can avoid unnecessary extensive surgery and speed up the institution of therapeutic procedures.

Odontoameloblastoma: five years follow up of a surgical case and review of literature.

The odontoameloblastoma (OA), also known as ameloblastic odontoma, is a rare neoplasm of jaws which includes odontogenic ectomesenchyme in addition to odontogenic epithelium that resembles an ameloblastoma both in structure and in behaviour. The exact incidence is difficult to determine. Since 1944, only 24 cases have been reported in English literature which fulfill both histological and clinical features of this lesion. The Authors report a case report of an odontoameloblastoma in a 15-year-old caucasian man treated with a surgical excision. The five years follow-up shows no evidence of recurrence confirming the validity of a conservative surgery with enucleation of OA, followed by periodical clinical and radiographical controls.

MMP-9 expression in meningiomas: a prognostic marker for recurrence risk?

Despite total macroscopic resection of meningiomas relapses do occur in these tumours, possibly because of microscopic clusters of neoplastic cells left in the dura mater or in the arachnoid membrane. The invasiveness of the neoplastic cells of human meningiomas has been related to expression of matrix-metalloproteinase-9 (MMP-9), a peptidase actively implicated in the degradation of the extracellular matrix; nonetheless, the prognostic value of MMP-9 in the risk of recurrence of meningiomas has not been sufficiently investigated. Herein, we analysed MMP-9 expression in a series of meningiomas of different histotype and histological grade and assessed its correlation with various clinico-pathological indicators and with the clinical outcome of these tumours. We also tested the eventual pro-angiogenic role of MMP-9 expression in meningiomas through its correlation with vascular endothelial growth factor (VEGF) and microvessel density (MVD) revealed in the same cases. MMP-9 expression was observed in 64% of cases; high expression of this protein was significantly associated with high histological grade and proliferation index, but not with high MVD, of the tumours. A trend towards correlation between MMP-9 and VEGF expression was found, although statistical significance was not reached. In addition, high MMP-9 expression was a negative independent prognostic factor associated with higher recurrence risk in totally resected meningiomas. In conclusion, we demonstrated for the first time the potential prognostic value of MMP-9 expression in meningiomas. Inhibition of MMP-9 may be a new therapeutic strategy to prevent recurrences of meningiomas, particularly the high-grade type.

Osteoblastic meningiomas: clinico-pathological and immunohistochemical features of an uncommon variant.

Osteoblastic meningioma is a rare variant of meningioma characterized by the presence of a variable number of bone spicules within the tumor parenchyma. Its histogenesis has not been yet fully clarified. Herein we report clinical and histological findings and expression of bone matrix proteins (osteocalcin and ostepontin) observed in seven osteoblastic meningiomas. None of the cases displayed recurrences or significant re-growth after partial resection. In 5/7 cases the osseous component occurred in association with psammoma bodies and dystrophic calcification. Interestingly, foci composed of immature bone trabeculae, mineralized chondroid matrix, and osteoclasts were found in one of the two cases with no psammoma bodies or calcification, suggesting enchondral ossification. Positive staining for osteocalcin, which is a marker of terminal osteoblastic differentiation, was observed within the bone spicules in all meningiomas, but not in the chondroid mineralized matrix. On the other hand, immuno-expression of osteopontin, an early osteogenic marker, was observed in the osteoclasts and in mature and immature bone spiculae, calcification, and psammoma bodies. Even more, osteopontin was extensively expressed by the neoplastic cells of cases without calcification or psammoma bodies, suggesting acquisition of osteoblastic phenotype in these meningiomas. In conclusion, osteoblastic meningioma seems to be an indolent variant of meningiomas characterized by a slow growth and good prognosis. Our histological and immunohistochemical findings suggest that bone formation may occur through two different pathways, i.e., as the final step of calcification or through a metaplastic mechanism in cases with absent calcification or psammoma bodies.

NGAL immunohistochemical expression in brain primary and metastatic tumors.

A significant association has been recently shown between the expression of neutrophil gelatinase-associated lipocalin (NGAL) in tumors and its urinary levels. Thus NGAL urinary detection has been proposed as a method for the early diagnosis of brain tumors. In view of this, the objective of this study was to investigate whether NGAL expression differs according to brain tumor type or in primary vs. metastatic brain neolasias. 42 surgically resected formalin fixed and paraffin embedded neoplasias, including 15 cases of brain metastasis and 27 cases of primary central nervous system (CNS) tumors (11 meningiomas; 1 pilocytic astrocytoma, 2 diffuse astrocytomas, 2 oligoastrocytomas, 2 oligodendrogliomas, 1 anaplastic oligoastrocytoma, 7 glioblastomas, 1 ependymoma) were submitted to the immunohistochemical procedure. Sections were incubated overnight with the primary antibody against NGAL. NGAL staining was found in all the analyzed glioblastomas and in the anaplastic oligoastrocytoma. No NGAL immuno-expression was evidenced in all the other cases. A statistically significant correlation was demonstrated between NGAL presence and high proliferation index in the primary tumors. In conclusion, our findings suggest that NGAL expression is restricted to high grade gliomas among primary brain tumors, and that brain metastases do not express this protein. Considering the correlation between NGAL expression in tumors and its urinary levels, if our observations will be further validated, NGAL urinary detection might be used as an additional tool in the pre-surgical definition of brain lesions involving difficult differential diagnosis.

Comparison of the Marsh-Oberhuber classification with a new grading system in identifying patients with latent celiac disease.

AIM: The diagnosis of celiac disease (CD) is still mainly based on pathological description. However, these descriptions are often unable to identify latent CD. The aim of this study was to evaluate whether the Marsh-Oberhuber classification and a recently proposed classification may help to identify patients with latent CD. METHODS: Biopsy samples from twelve patients with latent CD (age range 3-32 years) defined as having normal duodenal mucosa when ingesting a free diet, and subsequently developing severe villous atrophy, were retrospectively reviewed in blind according to the Marsh-Oberhuber classification and the new grading system. RESULTS: In 67% of patients the Marsh-Oberhuber and the new classification could have yielded a diagnosis of CD soon after the first biopsy (3a-3c score when reviewed according to this classification, and B2 score when reviewed according to the new grading system), thereby avoiding further (up to two more in four cases) unnecessary endoscopic procedures. CONCLUSION: Both the Marsh-Oberhuber and the new classification allow to discriminate latent CD from patients with normal mucosa. Thus, these classifications may help in identifying and treating patients at an early stage.

Immunohistochemical localization and functional characterization of somatostatin receptor subtypes in a corticotropin releasing hormone- secreting adrenal phaeochromocytoma: review of the literature and report of a case.

Somastostatin receptors are frequently expressed in phaeochromocytoma but data on somatostatin receptor subtyping are scanty and the functional response to the somatostatin analogue octretide is still debated.We report an unusual case of pheochro-mocytoma,causing ectopic Cushing's syndrome due to CRH production by the tumour cells, in a 50-yr-old woman. Abdominal computed tomography revealed an inhomogeneous,9-cm mass in the right adrenal gland,and [111In-DTPA0] octreotide scintigraphy showed an abnormal uptake of the radiotracer in the right perirenal region,corresponding to the adrenal mass.The patient underwent laparoscopic surgery and formalin-fixed and paraffin embedded samples were studied. The tumour was extensively characterized by immunohistochemistry and somatostatin receptor (SSTRs) subtypes expression was analyzed.Histological and immunohistochemical examination of the surgical specimens displayed a typical pheochromocytoma,which was found to be immunoreative to S-100, chromogranin A and neurofilaments. Immunostaining for SSTR subtypes showed a positive reaction for SSTR1, SSTR2A, SSTR2B, antisera on tumour cells. The intense and diffuse immunostaining for corticotropin releasing hormone (CRH) antiserum indicated that Cushing's disease was dependent on CRH overproduction by the pheochromocytoma,in which no immunostaining for adrenocorticotropic hormone was found. Our report confirms the heterogeneity of the pattern of SSTR expression in pheochromocytomas,and provide further evidence for functional SSTR subtype SSTR2a in a subgroup of pheochromocytomas,suggesting that these tumours may represent potential target for octreotide treatment.

Caveolin-1 immuno-expression in human gastric cancer: histopathogenetic hypotheses.

The immunohistochemical expression of caveolin-1 (cav-1) was evaluated in a series of gastric carcinomas (GC) and in the adjacent normal gastric mucosa. Cav-1 immuno-expression was found in most GC (94%) with a significantly higher amount in the Lauren intestinal type in comparison to the diffuse-type carcinomas. Interestingly, gastric intestinal metaplasia as well as the cells at the base and neck of gastric pits within all fundic mucosal fragments showed an evident cav-1 immuno-staining, suggesting a histogenetic derivation of these lesions from the trans-differentiation of chief cells or from a cryptic progenitor population at the base of fundic glands, as recently hypothesized by other authors. The absence of significant correlations between cav-1 immuno-expression and the other clinico-pathological parameters, such as the stage of disease or the patients overall survival, indicates that the role of cav-1 in GC is neither stage-specific nor related to prognosis.

Sstr2A immunohistochemical expression in human meningiomas: is there a correlation with the histological grade, proliferation or microvessel density?

Somatostatin anti-proliferative and anti-angiogenic activities, together with the expression of somatostatin receptors (sstrs), account for the use of somatostatin analogues in the treatment of human tumours. In the present study, sstr2A immunohistochemical expression was analyzed in grade II and III meningiomas and was compared with that revealed in grade I meningiomas. Thirty-five formalin-fixed paraffin-embedded meningiomas, comprising 13 grade I, 19 grade II and 3 grade III tumours, according to the WHO 2007 classification, were submitted to immunohistochemical assays for sstr2A. Moreover, in the same cohort of tumours, the immunoexpression of CD105, a specific marker for neo-angiogenesis, as well as the Ki-67 labelling index (LI), reflecting the proliferative activity of the meningiomas, were recorded. Sstr2A immunoreaction was evidenced in 26/35 cases and was localized at the cytoplasm and the plasma membrane in 12 and in 14 cases, respectively. Specifically, a positive staining was found in 7/13 grade I, in 16/19 grade II and in 3/3 grade III tumours, thus demonstrating that sstr2A is frequently expressed in high grade meningiomas. A significantly higher microvessel density (MVD), assessed by CD105 immunostaining and Ki-67 LI were evidenced in high grade meningiomas. A significant correlation was recorded between sstr2A expression and a high MVD of the meningiomas. The existence of a correlation between sstr2A expression and the entity of neo-angiogenesis provides the basis for the use of somatostatin analogue-based therapies in the treatment of meningiomas.

Actinic keratosis associated with squamous and basal cell carcinomas: an evaluation of neoplastic progression by a standardized AgNOR analysis.

In an attempt to investigate the neoplastic progression in different stages of actinic keratosis (AK), a standardized AgNOR analysis was performed in 94 cases of AK, 35 of which were associated with squamous cell carcinoma (SCC) or basal cell carcinoma (BCC), and in 31 cases of SCC and 22 cases of BCC. The cases were subdivided into low- and high-AgNOR-expressing (AgNOR status) AK by using the mean area of AgNORs per cell (NORA) value (3.996 micro(2)) as the cut-off. In AK samples, a progressive increase of the mean NORA value from Stage I to Stage IV was encountered. In addition, a significantly higher mean NORA value was found in the AK cases associated with SCC, in comparison to those without SCC; by contrast, no significant differences in the mean NORA value were noted between AK cases with or without BCC. A highly significant association between a high AgNOR quantity and the coexistence of SCC was encountered in AK; no association was appreciable between the AgNOR quantity and the co-occurrence of BCC. Moreover, when the co-existence of SCC in AK was considered as the reference point, the AK cases associated with SCC mostly (95.5%) presented a high AgNOR quantity (high sensitivity), but only 57.6% of cases without SCC displayed a low AgNOR quantity (low specificity). Additionally, our data document that the standardised AgNOR analysis represents a strong negative predictor for the association between SCC and AK. Indeed, a low AgNOR quantity mostly is associated with AK cases without SCC.

Relationship between immunoexpression of mucin peptide cores MUC1 and MUC2 and Lauren's histologic subtypes of gastric carcinomas.

Laurèn's system subdivides gastric cancers into an intestinal type and a diffuse type. This histological classification mirrors histogenetic hypotheses according to which the intestinal-type cancer derives from intestinal metaplasia and dysplasia, while the diffuse-type originates directly from gastric mucosa, with or without a preceding non-metaplastic dysplasia. Studies concerning mucins expression in gastric neoplastic and preneoplastic lesions have provided contradictory data concerning such histogenetic relationships. The aim of the present study was to verify whether a correlation between mucins phenotype and Lauren's classification subsists. 40 gastric adenocarcinomas, subdivided, according to Laurèn's classification, into 27 intestinal-type, 10 diffuse-type and 3 unclassified cases, were examined for MUC1 and MUC2 immunohistochemical expression. Intestinal-type carcinomas displayed a MUC1-positive staining in 23/27 cases and a MUC2-positive immunoreaction in 10/27 cases. Diffuse-type carcinomas expressed MUC1 in 3/10 and MUC2 in 8/10 cases, respectively. According to the mucins expression pattern, three phenotypes were identified: the gastric phenotype (MUC1+/MUC2-); the gastro-intestinal phenotype (MUC1+/MUC2+) and the intestinal phenotype (MUC1-/MUC2+). The gastric phenotype was significantly higherin intestinal-type adenocarcinomas, whereas cases showing an intestinal phenotype were significantly more frequent in diffuse-type adenocarcinomas. These findings provide evidence for a lack of correlation between Lauren's classification and MUC1 and MUC2 phenotypes. In particular, the term intestinal-type tumour as referred to gland-forming gastric cancer does not seem to reflect an immunohistochemical phenotype.

Quantity of AgNORs in gastric endocrine carcinoid tumours as a potential prognostic tool.

In order to assess if the quantity of silver-stained nucleolar organizer region (AgNOR) proteins represents a prognostic tool in gastric carcinoids, a standardised AgNOR analysis was performed on 24 samples collected from the pathology archives of the Universities of Messina and Parma; the samples were taken at surgery from 11 males and 13 females (mean age 55 yrs, age range 28-77 yrs); 13 cases were defined as Type I, 1 case as Type II and 10 cases as Type III; 16 cases showed a diameter <1 cm, 8 >1 cm. Only 6 tumours were deeply invasive, breaking through the muscularis propria or the subserosa. The proliferative status of carcinoids performed by Ki67 protein antibodies was available in 20/24 cases. The quantification of AgNORs was performed according to the guidelines of the Committee on AgNOR Quantification and the mean area (microm2) of AgNORs per nucleus (NORA) was determined by means of image analyser and specific software programs. The relationship between NORA values and Ki67 data was investigated by Spearman correlation test. The mean NORA value of all 24 gastric carcinoids was 1.279 microm2 (SD 0.404); values ranged from 0.734 to 2.142 microm2. A significantly higher (p < 0.001) mean NORA value (1.736 microm2; SD 0.283) was found in tumours larger than 1 cm, in comparison to the smaller neoplasms (1.051 microm2; SD 0.214); moreover, cases showing deep wall invasion exhibited a mean NORA value of 1.765 microm2 (SD 0.276), significantly higher (p < 0.001) than those with superficial growth (1.118 microm2; SD 0.296). Finally, a similar highly significant difference was seen between type III carcinoids (1.615 microm2; SD 0.375) and type I-II (1.040 microm2; SD 0.208). A linear relationship between Ki67 and corresponding NORA values was obtained by the Spearman correlation test (p = 0.001). No other significant correlations were found between mean NORA values and other clinico-pathological parameters. The AgNOR method seems to be an additional tool potentially able to predict the prognosis of this kind of endocrine tumour, facilitating the identification of fast-growing tumours and being able to directly correlate with the size, deep invasion of gastric wall and tumour type, generally considered as the best prognostic indicators.

Immunolocalization of lactoferrin in surgically resected pigmented skin lesions.

Lactoferrin (Lf) expression was determined immunohistochemically in 57 formalin-fixed paraffin-embedded bioptic samples obtained from an equal number of patients treated by surgery to remove pigmented skin lesions (nevi = 23; melanoma = 12; vulgaris and seborrhoeic warts = 12; basal cell carcinoma = 10); in addition, 10 specimens of normal skin were studied as control. On 3 mm thick sections, depigmentation and antigen retrieval procedures were performed. The Lf immunoreactivity was revealed by a rabbit anti-human Lf. Quantification of Lf immunoreactivity was performed using an intensity-distribution (ID) score. Melanocytic cells, regardless of their benign or malignant nature, were consistently stained, with no significant differences in the Lf ID-score between melanomas or nevi. A different intensity of Lf immunoreactivity was encountered in superficial portions of warts, exclusively inside squamous epithelial cells arranged in sheets or whorls of keratin. On the contrary, basal cell carcinomas were always unstained, while a slight Lf positivity was found in focal keratinized areas present in two tumours showing baso-squamous differentiation. The Lf immunoreactivity was localized in the cytoplasm and only occasionally in the nucleus. The biological meaning of Lf in these cases of human skin specimens remains unexplained, although it cannot be ruled out that Lf might be involved in the defense system against tumours, or alternatively, may be used by cells requiring iron availability for their turnover. Moreover, the immunohistochemical expression of Lf in melanocytic lesions might be also related to a Lf-melanin interaction. Finally, the involvement of Lf in skin squamous non-neoplastic elements could be related to its role as one of the molecules modulating an unspecific inflammatory or anti-oxidant response.

HER2 Status in Premalignant, Early, and Advanced Neoplastic Lesions of the Stomach.

OBJECTIVES: HER2 expression in gastric cancer (GC) has received attention as a potential target for therapy with Trastuzumab. We reviewed the current knowledge on HER2 status in premalignant gastric lesions and in early (EGC) and advanced (AGC) GC to discuss the possible pathogenetic and prognostic roles of HER2 overexpression in GC. RESULTS: HER2 overexpression was documented in gastric low-grade (LG) and high-grade intraepithelial neoplasia (HG-IEN), with higher frequency in gastric type dysplasia. HER2 overexpression was significantly associated with disease recurrence and poor prognosis in EGC representing an independent risk factor for lymph node metastases. HER2 overexpression was more frequent in AGC characterized by high grade, advanced stage, and high Ki-67 labeling index. The discordance in HER2 status was evidenced between primitive GC and synchronous or metachronous metastases. CONCLUSIONS: HER2 overexpression in premalignant gastric lesions suggests its potential involvement in the early steps of gastric carcinogenesis. The assessment of HER2 status in EGC may be helpful for the identification of patients who are at low risk for developing nodal metastases. Finally, the possible discordance in HER2 status between primary GC and its synchronous metastases support routine assessment of HER2 both in the primary GC and in its metastatic lesions.

Iron binding proteins in gallbladder carcinomas. An immunocytochemical investigation.

By immunohistochemistry, the presence of major iron-binding proteins (lactoferrin, transferrin, ferritin) has been investigated in adenocarcinomas (27 cases), adenosquamous carcinoma (1 case), undifferentiated sarcomatoid carcinoma (1 case) and mucinous adenocarcinomas (3 cases) of the gallbladder 10 samples of chronic lithyasic cholecystitis, 4 adenomyomas and 6 tubulo-villous adenomas have also been studied. In a variable share of adenocarcinomas, a positive immunoreactivity for iron-binding antisera was encountered in the cytoplasm, while tubulo-villous adenomas, adenomyomas and the normal epithelium of the gallbladder were generally unreactive. In carcinomatous lesions, the staining intensity was variable between different cases or individual tumour cells. The production of these iron-binding proteins in the gallbladder carcinoma in itself could be related to a greater availability of iron for metabolic processes in the neoplastic cell; alternatively, the cytoplasmic localization of these substances in carcinomatous elements may be a consequence of a defective or impaired function of iron-binding receptors with a modified degree of transmembranous iron transfer.

Immunohistochemical detection of metallothionein in carcinomatous and normal human gastric mucosa.

Utilising a specific monoclonal mouse antibody (E9), metallothionein (MT) expression has been immunohistochemically investigated in 112 formalin-fixed paraffin-embedded surgical gastric samples, 38 of which were early carcinomas (EGC) and 74 advanced ones (AGC); clinico-pathological details and follow-up data (ranging from 3 to 197 months, mean 60.5 months) were available. Eighty-nine portions of gastric mucosa adjacent to examined carcinomas (transitional mucosa) were also analysed; in addition, 22 biopsies of normal gastric mucosa were studied as tissue control. The MT immunoreactivity was evaluated by staining and intensity-distribution scores. A various MT positivity was appreciable in the cytoplasm and nucleus of antrum or body gastric epithelial cells in 100% of normal control biopsies. 75/112 (67%) gastric carcinomas showed MT immunoreactivity with a significant lower expression in AGC. No relationships were encountered between MT immunostaining and clinico-pathological data; in addition, no difference in the Kaplan-Meier survival curves of patients with various MT expression was achieved. When the transitional mucosa was examined, 84/89 (94%) samples were stained although the immunoreaction was not always concordant with that encountered in adjacent carcinomatous elements. The significant statistical decrease of MT scores observed by us moving from normal to neoplastic gastric mucosa allows us to exclude the hypothesis of an overexpression of MT in gastric carcinomas.

The use of microwave irradiation for immunohistochemistry: a new methodological proposal.

We developed a rapid immunohistochemical method using a microwave oven in formalin-fixed, paraffin-embedded sections from normal and pathological tissues. The strongest immunoreactivity was obtained for actin, Ca 125, CEA, pan-cytokeratin, chromogranin A, EMA, GFAP, thyroglobulin, kappa and lambda chains. In control tissues, processed with conventional immunocytochemical procedure, the reactivity was found to be qualitatively and quantitatively similar. Dako EPOS kits were also assayed with good staining intensity, shortening the original technique to 16 min. Our microwave immunohistochemical method is simple, rapid and it may be recommended for use in routine laboratories.

Iron-binding proteins in human colorectal adenomas and carcinomas: an immunocytochemical investigation.

By immunocytochemistry, the presence of major iron-binding proteins (lactoferrin, transferrin and ferritin) was investigated in tubular adenomas (12 cases), villous adenomas (7 cases), carcinomas of the large bowel and rectum (39 cases) and lymph nodes involved in carcinomas (8 cases); 5 samples of colonic inflammatory pseudopolyps were also studied. Dysplastic areas of tubular and villous adenomas as well as adenocarcinomas and colloid carcinomas showed a variable cytoplasmic immunoreactivity for all antisera, although no staining was noted in some cases; tubular adenomas without dysplasia and colonic inflammatory pseudopolyps were always unstained. Metastatic elements present in lymph nodes maintained the immunohistochemical staining for iron-binding proteins. An autoctone production of lactoferrin, transferrin and ferritin by tumour cells may be hypothesized in relation to the increased requirement of iron for the turnover of rapidly dividing cells.

Acinar cell carcinoma of the pancreas. A histologic, immunocytochemical and ultrastructural study.

A rare case of acinar cell carcinoma of the pancreas is presented. Because of its unusual solid growth pattern, correct diagnosis required electron microscopic analysis and the demonstration of intracellular amylase by immunohistochemical stains. The presence of pleomorphic electron-dense cytoplasmic granules containing fibrillary internal structures is confirmed in this ultrastructural study. The differential diagnosis of acinar cell carcinoma from other neoplasms involving the pancreas, including neuroendocrine tumours, poorly-differentiated adenocarcinomas and neoplasms of putative acinar cell derivation, is discussed.