Reproducible and highly sensitive detection of the broad spectrum epithelial marker keratin 19 in routine cancer diagnosis

 

Aims:

In this study the recently developed keratin 19 antibody RCK108 is biochemically and immunohistochemically characterized. Its applicability as a keratin marker in routinely processed histological tissue specimens is assessed.  

Methods and results:

The keratin 19 antibody RCK108 antibody was tested on normal and malignant routinely formalin-fixed, paraffin-embedded tissue specimens. It stains most, although not all, glandular epithelia and showed (focal) reactivity in the basal cell compartment of stratified epithelia. It was found to react with most epithelial tumours, including adenocarcinomas, squamous cell carcinomas and endocrine tumours of various origins.  

Conclusions:

Its reproducible and highly sensitive staining characteristics make RCK108 a useful antibody to be applied as a broad epithelial marker for carcinoma detection in routinely processed paraffin sections. As such, RCK108 is a specific reagent for practically all epithelial tumours. A few types of epithelial malignancies, known not to contain keratin 19, were negative for RCK108. Therefore the antibody is also useful in some narrow differential diagnostic considerations such as cholangiocellular carcinoma (RCK108 positive) vs. hepatocellular carcinoma (RCK108 negative). Another important feature of this antibody is that it shows very little reactivity in mesenchymal tissues, or mesenchymally derived tumours, as is frequently described for other keratin antibodies. A few leiomyosarcomas showed sporadic reactivity.     

Adenomyoepithelioma of the skin: a case report with immunohistochemical and ultrastructural observations

 

Aims:

The histological, immunohistochemical and electron microscopic features of a primary adenomyoepithelioma of skin, a rare sweat gland tumour, are reported.  

Methods and results:

The tumour occurred on the back of a 92-year-old woman. It was composed of well-formed tubules lined by epithelial cells surrounded by clear or spindled myoepithelial cells. Immunohistochemically, the epithelial cells exhibited strong cytokeratin (CAM5.2) and weak carcinoembryonic antigen positivity. The myoepithelial cells showed diffuse positivity for smooth muscle actin and focal positivity for S100 protein. Ultrastructurally, the myoepithelial cells contained myofilaments with focal densities and hemi-desmosomes. They were limited by well-formed basal lamina. The tumour was associated with a small eccrine spiradenoma.  

Conclusion:

We predict that the tumour will behave in a benign fashion. There is no evidence of recurrence or metastasis 28 months later.     

Lesions of 13q may occur independently of deletion of 16q in spindle cell/pleomorphic lipomas

 

Aims:

Very recent multidisciplinary investigations have allowed for the definition among lipomas of a clinical and histological subtype called spindle cell and/or pleomorphic lipoma, possibly associated with partial monosomy 16 and anomalies of chromosome 13. In order to get nearer to the underlying critical molecular changes further multidisciplinary pathological and genetic research is indicated, to identify which chromosome(s) anomalies are crucial in the development of these tumours.  

Methods and results:

In an ongoing multidisciplinary study of lipomatous tumours, including clinical findings, morphology, histochemistry and cytogenetics, two instances were found of spindle cell lipoma with clonal chromosome changes. In both cases chromosome 13 was involved, whereas only one showed a partial monosomy 16.  

Conclusions:

Partial monosomy 16 is a characteristic lesion in spindle cell lipoma, usually associated with anomalies of chromosome 13. The present report confirming a previous single observation indicates, however, that lesions of 13 may occur independently from lesions of 16, suggesting different underlying molecular lesions in these otherwise very similar lipomas.     

Synovial sarcoma of the pleura and its differentiation from other primary pleural tumours: a clinicopathological and immunohistochemical review of three cases

Aims : Synovial sarcomas are rare tumours occasionally arising in the pleural cavity, a site where their histological characteristics may be mistaken for those of malignant mesothelioma. We examined three cases of primary pleural synovial sarcoma in order to look for clinicopathological features that may help in distinguishing them from both mesotheliomas and other sarcomas that may arise in the pleura.  

Methods and results

All three patients were male, aged 42, 28 and 42, respectively, and had no known exposure to asbestos. One biphasic tumour contained neutral mucin in focal epithelial elements that also stained positively for BerEP4 and AUA1. All three tumours showed focal positivity for either keratin or EMA in the sarcomatous elements, and they also stained positively for bcl-2 protein and MIC2 gene product (CD99).  

Conclusions

Our results emphasize the importance of being aware of synovial sarcoma as a possible primary pleural malignancy, especially in a young patient with a localized mass. In addition, the presence of bcl-2 protein perhaps represents a useful marker in distinguishing synovial sarcoma, especially monophasic variants, from mesothelioma within a panel of antibodies.     

Expression of stratified epithelial-type cytokeratins in hyalinizing trabecular adenomas supports their relationship with papillary carcinomas of the thyroid

 

Aim:

To evaluate the cytokeratin pattern of expression of hyalinizing trabecular adenomas and to verify whether or not these tumours, that share morphological features with papillary carcinomas, present the stratified epithelial-type cytokeratins commonly found in ordinary papillary carcinomas.  

Methods and results:

This study consisted of the immunohistochemical detection of simple and stratified epithelial type cytokeratin filaments in a series of six hyalinizing trabecular adenomas, three papillary carcinomas with a trabecular growth pattern and two carcinomas combining hyalinizing trabecular and papillary patterns. Simple epithelial-type cytokeratins 7, 8, 18 and 19 were found in every case. Expression of the stratified epithelial-type cytokeratins 1, 5/6 and/or 13 was detected in four hyalinizing trabecular adenomas.  

Conclusion:

Based on this, as well as on the cytological features and on the frequent co-occurrence of hyalinizing trabecular adenoma and papillary carcinoma, we suggest that the former lesion may be considered a peculiar encapsulated variant of papillary carcinoma.     

Clinicopathological and interphase cytogenetic analysis of desmoid tumours

 

Aims:

Recurrence of desmoid tumours is difficult to predict from only histological findings. In this study, immunohistochemistry for counting stromal blood vessels and proliferative activity, DNA flow cytometry, and interphase cytogenetic analysis of chromosome 8 by fluorescence in-situ hybridization (FISH) were performed to assess the correlation between their parameters and the recurrence of desmoid tumours.  

Methods and results:

The cases examined included 16 extra-abdominal desmoid and eight abdominal desmoids, comprising 14 recurrent and 10 non-recurrent cases. Eleven (69%) of the 16 extra-abdominal desmoids and three (38%) of the eight abdominal desmoids recurred. Patients with recurrent lesions (mean age, 20 years) were younger than those with non-recurrent tumours (34 years). Histologically, tumours with hypervascular areas frequently recurred after surgery in comparison with those with hypovascularity. There was no significant correlation between tumour size, the labelling index of the proliferating cell nuclear antigen (PCNA) and the recurrence. In flow cytometric analysis, all the cases examined showed a diploid pattern. The FISH study revealed that the incidence of trisomy 8 was significantly higher in the recurrent (72.7%) than in the non-recurrent cases (12.5%).  

Conclusions:

These results suggest that a subgroup of desmoid tumours at risk of recurrence may be hypervascular lesions associated with trisomy 8.     

Thyroid carcinoma associated with familial adenomatous polyposis

 

Aims:

Thyroid carcinoma is an extracolonic manifestation that is present in about 1% to 2% of patients with familial adenomatous polyposis (FAP). Less than 100 cases have been reported in detail. We have investigated the suggestion that FAP associated thyroid carcinoma is significantly different morphologically from both papillary and follicular types and can be considered as a separate entity.  

Methods and results:

Specimens from three patients with FAP associated thyroid tumours, all but one having single nodules, have been analysed. All three patients belonged to an extended kindred (23 siblings in four generations) who had genetic analysis and intensive screening for thyroid nodules. Seven patients had the same APC mutation at codon 1061. Pathological examination revealed a typical papillary carcinoma, encapsulated variant, in all patients, with follicular areas in one case. All thyroid specimens, in addition to histological and immunohistological examinations, were also specifically studied for activation of the RET-PTC oncogene, that seems to be restricted to papillary thyroid carcinoma. Two of the three patients had RET-PTC activation (PTC₁ isoform).  

Conclusions:

The findings suggest that the tumours were certainly papillary, at least in the present kindred. Further studies in different families are required for a better understanding of this peculiar tumour and of its biological behaviour.     

Carcinosarcoma of the oesophagus showing neuroendocrine, squamous and glandular differentiation

 

Aim:

A case of oesophageal carcinosarcoma occurring in a previously fit, 64-year-old man is reported.  

Case summary:

The carcinomatous component displayed neuroendocrine, squamous and glandular differentiation; the sarcomatous component showed no specific features of differentiation. In-situ squamous carcinoma was present in the adjacent squamous mucosa. The most superficial part of the invasive tumour consisted of carcinosarcoma with a predominant neuroendocrine epithelial component. Squamous carcinoma without an accompanying sarcomatous component occupied most of the deeper part of the tumour, suggesting outgrowth of this tumour type by a selective growth advantage.  

Conclusion:

We speculate that further tumour growth might have led to complete replacement of the tumour by pure squamous carcinoma, and that other advanced oesophageal squamous carcinomas might have had their origin in a short-lived carcinosarcomatous phase.     

Hepatic stem-like cells in hepatoblastoma: expression of cytokeratin 7, albumin and oval cell associated antigens detected by OV-1 and OV-6

 

Aims:

In a recent study we described a population of small epithelial cells (SEC) in human hepatoblastoma that exhibit ultrastructural features of the oval cells of rodents. Both SEC and oval cells are immunoreactive for cytokeratin 7, a marker of biliary differentiation, and it was postulated that SEC, like oval cells, are closely related to hepatic stem cells. This study was undertaken to investigate whether SEC also exhibit immunolabelling for albumin, a marker of hepatocytic differentiation, and to determine whether other antigens typical of oval cells are detectable in hepatoblastoma.  

Methods and results:

Hepatoblastomas of various subtypes were investigated by electron microscopy, and by immunohistochemistry with the monoclonal antibodies OV-1 and OV-6, which recognize antigens associated with oval cells. Double-labelling for cytokeratin 7 and albumin was carried out by immuno-electron microscopy. OV-1 stained scattered cells in seven of 12 tumours investigated and OV-6 in nine. On immunoelectron-microscopic investigation, SEC exhibited labelling for both cytokeratin 7 and albumin.  

Conclusions:

The results demonstrate that antigens associated with oval cells are found in certain cells in hepatoblastoma. SEC, like oval cells, co-express markers for hepatocytic and biliary differentiation. The findings further support the hypothesis that SEC are closely related to the putative bipotent hepatic stem cell, which, by definition, gives rise to both hepatocytes and biliary epithelial cells.     

Pancreatic tissue in a lateral cervical cyst attached to the thyroid gland—a presumed foregut remnant

 

Aim:

To report the previously undescribed occurrence of a lateral neck cyst, attached to the thyroid gland, containing pancreatic tissue.  

Methods and results:

A 41-year-old man presented with a recurrent cystic lesion of the thyroid. At thyroidectomy cystic masses containing mucinous material were present in the neck, and there was a nodular lesion attached to the lower pole of the thyroid. Histological examination of the latter lesion revealed an epithelial lined cyst, with pancreatic tissue (exocrine and endocrine) in addition to fat, fibrous tissue, muscle and cartilage in the wall.  

Conclusions:

The possible origin of this structure is discussed, with the conclusion being that it most likely represents a foregut remnant.     

Down-regulation of CD95 (Fas/Apo-1) in the epithelia of adenovirus-infected appendices

 

Aims:

Adenoviral inclusions are commonly seen in appendices from infants with intussusception. They are associated with focal epithelial budding and less frequently with epithelial shedding. These morphological changes could depend on the opposing effects of adenoviral gene products on CD95-mediated apoptosis.  

Methods and results:

Appendices from intussusceptions with viral inclusions ( n  = 4) and normal appendices ( n  = 10) were studied by immunochemistry with anti-adenovirus, anti-CD95 and anti-HLA-DR antibodies. Apoptosis was studied by the TUNEL method. The mucosa of normal appendices contained no adenoviral protein. CD95 was present in all epithelial cells except Paneth cells. HLA-DR was absent in epithelial cells and apoptosis was seen only in germinal centres and in a few surface epithelial cells. The epithelium of appendices from intussusceptions contained nuclear inclusions labelled with anti-adenovirus antibody, always found in the epithelial buds. The epithelial CD95 pattern was drastically altered in adenovirus-infected appendices. CD95 was absent from the budding foci. In these foci, HLA-DR was overexpressed. There was also increased epithelial apoptosis in areas remote from those lacking CD95 antigen.  

Conclusions:

The appearance of epithelial budding or shedding in appendices from intussusception could be due to focal in situ differences in the expression of adenoviral genes.     

p53 tumour suppressor gene protein expression in early and advanced gallbladder carcinoma

 

Aims:

Gallbladder carcinoma is one of the most frequent malignant tumours occurring in Chile and the mortality rate in both sexes ranks among one of the highest in the world. Mutation of p53 tumour suppressor gene has been demonstrated in many tumours. Our aim was to determine protein expression of p53 gene in early and advanced gallbladder carcinoma.  

Methods and results:

Protein expression of gene p53 was studied by immunohistochemical means in 191 gallbladder carcinomas (157 primary tumours, 34 metastases) and 25 controls. In 86 out of 191 cases (45%), protein expression of gene p53 was observed. Differences related to sex, age, or race were not observed. All gallbladder controls were negative. Twenty-five per cent of well-differentiated tumours were p53 positive, while moderate or poorly differentiated carcinomas reached 50% ( P  = 0.04). p53 expression was observed in 23.5% of early carcinomas and in 48.2% of advanced carcinomas ( P  = 0.01). No differences between primary tumours and metastasis were demonstrated.  

Conclusions:

Protein expression of p53 tumour suppressor gene is observed in 45% of gallbladder carcinomas. The absence of expression in controls and in normal mucosa adjacent to tumours suggests its utility in differentiating atypical gallbladder epithelia from neoplastic lesions.     

Expression of c-Met correlates with grade of malignancy in human astrocytic tumours: an immunohistochemical study

 

Aims:

Recent studies suggest the involvement of hepatocyte growth factor/scatter factor (HGF/SF) in glioma cell invasion and tumour progression. We investigated the distribution and rate of tumour cells that express c-Met protein, which is the cell-surface receptor for HGF/SF, in astrocytic tumours. The type of cells that express c-Met in tumour tissues was also identified.  

Methods and results:

c-Met expression was screened immunohistochemically in a total of 43 astrocytic tumours, including 14 low-grade astrocytomas (A), 13 anaplastic astrocytomas (AA) and 16 glioblastoma multiforme (GBM). c-Met reactivity was demonstrated predominantly in the cytoplasm of tumour cells. Bizarre large tumour cells tended to stain intensely. Higher c-Met expression levels (≥ 2 +, more than 25% cells were positive) were noted in 21.4% of (A) vs. 53.8% in (AA) and 87.5% in (GBM) ( P  < 0.001), indicating a clear relationship between c-Met protein staining and higher grade astrocytic tumours. Moreover, c-Met immunoreactivity was also shown in tumour microvasculature, reactive astrocytes, and neurones in the cortex infiltrated by glioma cells. In 85.7% of cases containing infiltrated cortex, neurones were positive vs. no neurones in non-neoplastic regions ( P  < 0.002).  

Conclusions:

This evidence suggests that c-Met expression in the brain could be associated with astrocytoma progression and also reactive process. Immunohistochemical determination of c-Met-expressing cell types helps to understand possible roles of c-Met in tumour tissues.     

Multinucleated stromal giant cells of testis

 

Aims:

This study documents the frequency of multinucleated stromal giant cells within the interstitium of the testis and looks for possible aetiological reasons for this occurrence.  

Materials and methods:

We examined sections of testes from 150 unselected autopsy cases finding stromal giant cells in 43%. An aetiological association between the occurrence of multinucleated stromal giant cells in this site and hormonal or other pathogenetic influences could not be established.  

Conclusions:

In many instances, this occurrence appears to be an age related phenomenon.     

Role of microliths in the aetiology of chronic submandibular sialadenitis: a clinicopathological investigation of 154 cases

 

Aims:

Confusion about the aetiology and pathogenesis of chronic submandibular sialadenitis led to the present investigation of 154 cases in which many clinical and histological features were analysed.  

Methods and results:

By far the greatest number of histological factors, namely liths, atrophy, fibrosis, parenchymal inflammation, lymphoid germinal centres, mucous and ciliary metaplasia, salivary extravasation and glycosaminoglycan accumulation, was related to the degree of inflammation, which appears to be of the greatest importance in the aetiology and pathogenesis. Inflammation, atrophy and fibrosis were related to duration of symptoms, which supports the concept of a chronological progression through increasingly severe histological changes.  

Conclusions:

Inflammation possibly arises from ascending infection in a normal gland and exerts an obstructive and destructive effect on the parenchyma with the development of the related histological changes and a vicious circle involving further ascending infection. Normal glands contain microliths that possibly by localized obstruction cause atrophic foci that are reservoirs for ascending infection. Microliths and liths were unrelated: microliths were related to age as in normal glands whereas liths were related to duration of symptoms and appeared to be secondary to the sialadenitis. Many glands showed minimal changes, which raises the possibility of conservative treatment.     

Immunophenotypic heterogeneity of hyalinizing trabecular tumours of the thyroid

 

Aims:

We studied 12 cases of hyalinizing trabecular tumour of the thyroid gland (HTT) with the aim of reviewing the cytological, histological and immunophenotypic features and of investigating the relationships of HTT with other thyroid neoplasms.  

Methods and results:

Eleven patients were female and one male, aged 8–74 years (median 58). Ten cases had a benign behaviour, while two cases were locally aggressive. Of the latter, one developed distant metastases and the other is a recent case. All patients are alive 6–311 months after diagnosis. Cytologically, HTT was characterized by hypercellular smears with aggregates of roundish cells having features of papillary carcinoma (nuclear grooves, vacuoles) and fragments of fibrous tissue. Histologically, prominent nesting, trabecular growth patterns and a hyaline stroma (partly positive for laminin and collagen type IV) were found. One case was associated with a papillary microcarcinoma. Two additional cases had extensive areas of papillary carcinoma. In one of these, hyalinized papillary stalks were observed. All tumours contained thyroglobulin but not calcitonin. High molecular weight cytokeratin (a marker of papillary carcinoma) was focally positive in 4/12 cases only and thyroperoxidase (a marker of follicular adenomas, but not of papillary carcinoma) was found in 3/12 cases.  

Conclusions:

The immunophenotypic profile and the morphological features suggest that HTTs are an heterogeneous group of tumours, some of them probably representing variants of papillary carcinoma with hyalinized stroma.     

Mammary epidermoid inclusion cysts after wide-core needle biopsies

 

Aims:

To investigate the prevalence of squamous epidermoid inclusion cysts after wide-core needle biopsy.  

Methods and results:

Epidermoid inclusion cysts were found in five of 17 surgical excisions (29%) after preliminary wide-core needle biopsies in a 7-month period. Thereafter they were not seen in 26 subsequent postwide-core surgical excisions in a period of 6 months.  

Conclusions:

The cysts appear to be an iatrogenic complication of wide-core biopsy, and need morphological recognition in order to avoid confusion with spontaneous squamous metaplasia of benign or malignant breast epithelium. Longer term implications are unknown.     

Identification of oncocytic lesions of salivary glands by anti-mitochondrial immunohistochemistry

 

Aims:

To evaluate the immunohistochemistry using an anti-mitochondria antibody in the investigation of various oncocytic lesions of the salivary glands.  

Methods and results:

Ten cases of adenolymphoma (Warthin's tumour) and one case each of benign oncocytoma and oncocytic carcinoma of the salivary glands were examined. Normal salivary glands were also tested. They were investigated immunohistochemically using mouse monoclonal antibody against human mitochondria. In normal salivary glands, epithelial cells of the striated ducts showed a thick linear immunoreactivity, which corresponded well to the intracytoplasmic distribution pattern of mitochondria. In addition, a small number of swollen epithelial cells showing an intense, finely granular immunoreactivity in the cytoplasm were scattered in the ductal system and acini ('oncocytic metaplasia'). Almost all neoplastic cells involved in adenolymphoma, benign oncocytoma, and oncocytic carcinoma showed an intense, finely granular immunoreactivity in the cytoplasm.  

Conclusions:

Immunohistochemistry using the anti-mitochondria antibody proved to be a highly sensitive and specific method for light microscopic identification of mitochondria and superior to routine H & E or PTAH stain especially in the detection of isolated oncocytic cells.     

Rapid verification of the identity of questionable specimens using immunohistochemistry with monoclonal antibodies directed against HLA-class I antigens

 

Aims:

A case report is presented in which an unexpected pathological diagnosis raised the possibility that biopsies of two patients were mixed-up. Since these biopsies were obtained from kidney transplant patients, the HLA-typings of both patients were known.  

Methods and results:

We developed an immunohistochemical method using HLA-class I specific monoclonal antibodies to recognize the donor and recipient antigens in these biopsies. Using this method we could confirm the identity of the patients of whom the biopsies had been taken.  

Conclusions:

This method, which uses the highly polymorphic HLA-system, is potentially useful for rapid and easy verification of the identity of specimens if a mix-up is suspected.     

Erythrophagocytic tumour cells in melanoma and squamous cell carcinoma of the skin

 

Aims:

Erythrophagocytosis is a characteristic feature of tumour cells in malignant histiocytosis, some leukaemias, lymphomas, and also reactive histiocytes in the haemophagocytic syndrome associated with a variety of infections and neoplasms. It has also been found exceptionally in metastatic malignant epithelial cells in bone marrow and lymph nodes. We present two cases, a cutaneous malignant melanoma and an acantholytic squamous cell carcinoma, in which erythrophagocytosis by tumour cells was demonstrable by both light and electron microscopy.  

Methods and results:

The melanocytic and squamous nature of these cells was supported by the immunohistochemical detection of HMB45, S100, and NKI-C3 in the former, and cytokeratin and EMA in the latter, and at ultrastructural level by the presence of melanosomes and tonofilaments, respectively.  

Conclusions:

This is, to our knowledge, the first documented report of erythrophagocytic tumour cells in human melanomas and primary carcinomas. Biological considerations apart, this unusual feature can prove to be of value to avoid a misdiagnosis of a variety of haematopoietic malignancies.