Clinicopathological and immunohistochemical analysis of oral melanocytic nevi and review of the literature.

INTRODUCTION: Oral melanocytic nevi (OMNs) are uncommon benign melanocytic tumors, histologically similar to their cutaneous counterparts. The aim of this study was twofold: to contribute to the epidemiology with a literature review with the first Spanish series of OMNs, and to report on clinicopathological, immunohistochemical and demographic findings. MATERIALS AND METHODS: A retrospective analysis of cases attended over the period 1999-2010 was carried out using data drawn from the pathology unit files at two public hospitals in the Spanish region of Andalusia, serving between them a population of 823.614 inhabitants (11%). RESULTS: Ten cases of OMNs were retrieved, accounting for 0.18% of the total 5499 oral biopsies performed over the period. The female-to-male ratio was 1.5:1; mean patient age was 30. The palate was the most common location (70%). Relative frequencies of histologic types were as follows: subepithelial (40%), common blue (30%), compound (20%) and junctional (10%). Immunohistochemical examination showed strong S-100 protein expression, variable reactivity to HMB-45 and high c-Kit expression by junctional melanocytes. Ki-67 was ≤3 in all cases. CONCLUSIONS: Although this first clinicopathologic analysis of OMNs reported in Spain was based on a small patient series, the results are in line with those reported in larger series and additionally provide new demographic data. Since OMNs and early melanomas are usually detected at routine dental examination, detailed oral exploration should always be performed, and in case of doubt a biopsy should be taken to ensure an accurate diagnosis.

Immunohistochemical study of the neural development transcription factors (TTF1, ASCL1 and BRN2) in neuroendocrine prostate tumours. / Estudio inmunohistoquímico de los factores de trancripción de desarrollo neural (TTF1, ASCL1 y BRN2) en los tumores neuroendocrinos de próstata.

OBJECTIVE: Prostatic small-cell neuroendocrine carcinoma is an uncommon malignancy that constitutes 0.5-1% of all prostate malignancies. The median cancer-specific survival of patients with prostatic small-cell neuroendocrine carcinoma is 19 months, and 60.5% of the patients have metastatic disease. Neural development transcription factors are molecules involved in the organogenesis of the central nervous system and of neuroendocrine precursors of various tissues, including the suprarenal gland, thyroid glands, lungs and prostate. MATERIAL AND METHODS: We present 3 cases of this uncommon condition, applying the new World Health Organisation criteria. We conducted studies through haematoxylin and eosin staining and analysed the expression of the neural development transcription factors achaete-scute homolog like 1, thyroid transcription factor 1 and the class III/IV POU transcription factors, as a new research line in the carcinogenesis of prostatic neuroendocrine tumours. RESULTS: In case 1, there was no TTF1 immunoexpression. Cases 2 and 3 had positive immunostaining for ASCL1, and Case 1 had negative immunostaining. BRN2 immunostaining was negative in case 1 and positive in cases 2 and 3. CONCLUSION: The World Health Organisation does not recognise any molecular or genetic marker with prognostic value. ASCL-1 is related to the NOTCH and WNT signalling pathways. ASCL-1, TTF1 and BRN2 could be used for early diagnosis and as prognostic factors and therapeutic targets.

Gastrointestinal stromal tumors (GISTs): SEAP-SEOM consensus on pathologic and molecular diagnosis.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the digestive tract, with an incidence of 1.1 cases/100,000 inhabitants/year. A group of experts from the Spanish Society of Pathology and the Spanish Society of Oncology met to discuss a brief update on GISTs and agree on aspects relating to the pathological and molecular diagnosis of these tumors. GISTs are generally solitary, well-circumscribed lesions of variable size (<10 mm-35 cm) that may present with intra- or extra-luminal parietal growth or a mixed-type (hourglass) growth pattern. Histologically, they are unencapsulated neoplasms displaying expansive growth and spindle-shaped (70%), epithelioid (20%), or mixed cellularity (10%). Mitotic activity is generally moderate or low and should be evaluated only in areas with high cellularity or higher mitotic frequency. The great majority of GISTs harbour mutually exclusive activating mutations in genes coding for the type III receptor tyrosine kinases KIT and PDGFRA; less commonly, GISTs have also been reported to display mutations elsewhere, including BRAF and NF1 and SDH-complex genes. The method most widely used to detect KIT and PDGFRA mutations is amplification of the exons involved by polymerase chain reaction followed by direct sequencing (Sanger method) of these amplification products. Molecular analyses should always specify the type of analysis performed, the region or mutations evaluated, and the sensitivity of the detection method employed.

Recommendations of a group of experts for the pathological assessment of tumour regression of liver metastases of colorectal cancer and damage of non-tumour liver tissue after neoadjuvant therapy.

Colorectal cancer (CRC) incidence has increased during the past decades in Spain, being the first malignant tumour in incidence. Observed mortality for CRC is mainly due to liver and lung metastases. The only curative treatment is surgery; new surgical techniques and neoadjuvant treatments have increased the number of surgery candidate patients. Patients should be managed with a multidisciplinary approach that includes imaging techniques, chemotherapy, surgery and pathological assessment. As an answer to this approach, a group of pathology experts interested on CRC liver metastases aimed to review the diagnosis and prognosis of liver mestastases and developed practical recommendations for its assessment. The expert group revised the current literature and prepared questions to be discussed based on available evidence and on their clinical practise. As a result, recommendations for the assessment of tumour regression of liver metastases are proposed, which could be implemented in oncology centres allowing assessment standardisation for these patients. Prospective multi-center studies to evaluate these recommendations validity will further contribute to improve the standard care of CRC liver metastases patients.

Guidelines for biomarker testing in gastroenteropancreatic neuroendocrine neoplasms: a national consensus of the Spanish Society of Pathology and the Spanish Society of Medical Oncology.

The annual incidence of neuroendocrine tumours in the Caucasian population ranges from 2.5 to 5 new cases per 100,000 inhabitants. Gastroenteropancreatic neuroendocrine tumours is a family of neoplasms widely variable in terms of anatomical location, hormone composition, clinical syndromes they cause and in their biological behaviour. This high complexity and clinical heterogeneity, together with the known difficulty of predicting their behaviour from their pathological features, are reflected in the many classifications that have been developed over the years in this field. This article reviews the main tissue and clinical biomarkers and makes recommendations for their use in medical practice. This document represents a consensus reached jointly by the Spanish Society of Medical Oncology (SEOM) and the Spanish Society of Pathology (SEAP).

Head and neck cancer. An aetiopathogenetic study of non-endemic lymphoepithelioma.

An aetiopathogenetic analysis of non-endemic nasopharyngeal carcinoma (NPC) in European and Southern American patient groups was performed. Specifically, the study sought to determine the proportion of Epstein-Barr Virus (EBV)-positive tumour cells in NPC patients in two very different populations (Europe and South America) in areas not associated with a high incidence of NPC. Clinical data (age, sex and onset of clinical disease) were also analyzed. A total of 50 NPC samples, 24 from a European hospital (EH) and 26 from two South American hospitals (SAH), were included. Nuclear staining for Epstein-Barr virus-encoded small RNA (EBER) was performed by in situ hybridization (ISH). Latent membrane protein 1 (LMP1) expression was measured by immunohistochemical (IHC) analysis. A higher incidence of NPC was observed in patients > 40 years of age in EH; in SAH, by contrast, the incidence was higher in patients aged ≤ 40 years. Cervical lymph node metastasis was detected in 31 patients (of whom 84.6% were from SAH). A total of 72% of samples were EBERpositive; the incidence of EBER positivity was greater in type 3 NPCs. EBV was detected in a large proportion of epithelial cells in samples from both EH and SAH (75% vs. 69.2%, respectively). An association was found between EBER detection in lymphocytes and patient origin (p = 0.0001). LMP1 expression was detected in 64% of patients. ISH for the detection of EBER is the most sensitive technique for demonstrating EBV in tumour tissue. The incidence of EBV was not significantly greater in either of the study populations, but was significantly higher in patients with type 3 NPC. Definitive histological diagnosis of NPC was reached earlier in EH than in SAH, where metastases were more frequently diagnosed, suggesting that the disease had reached a more advanced stage by the time treatment was started.

Application of fluorescence in situ hybridization as a diagnostic tool in melanocytic lesions, using paraffin wax-embedded tissues and imprint-cytology specimens.

BACKGROUND: Accurate histopathological diagnosis of certain melanocytic skin lesions as benign or malignant can be notoriously difficult. Recently, four-colour fluorescence in situ hybridization (FISH) has emerged as an important tool for classifying these lesions. AIM: To evaluate the sensitivity and specificity of a melanoma FISH probe kit for accurate diagnosis of melanocytic tumours, and to validate its use with imprint-cytology specimens from the cut surface of tumours. METHODS: In total, 50 melanocytic skin lesions (31 malignant melanomas, 10 benign melanocytic naevi, and 9 histologically challenging benign melanocytic skin lesions) were evaluated. The samples comprise 47 tissue specimens embedded in paraffin wax, and three imprint-cytology specimens from the cut surface of melanomas. FISH was performed using four locus-specific identifier probes [Ras responsive element binding protein (RREB)1, myeloblastosis viral oncogene homologue (MYB), cyclin (CCN)D1 and centromere of chromosome (CEP)6], and results were compared with the clinical long-term follow-up and histopathological diagnosis data. RESULTS: The melanoma FISH probe distinguished between naevi and melanomas with a sensitivity of 100% and a specificity of 94.1%. The most sensitive criterion was a gain in 6p25 (RREB1), seen in 100% of cases, followed by CEP6-related MYB loss (48.1%), CCND1 gain (37%) and MYB gain (22.2%). More than three-quarters (77.8%) of melanomas were positive for two or more criteria. Positive FISH results were also obtained for the imprint-cytology specimens. CONCLUSIONS: FISH is a valuable diagnostic tool for differentiating between benign and malignant melanocytic lesions, providing a high degree of sensitivity and specificity. The probes displayed exceptional discriminative capacity in difficult or ambiguous lesions. To our knowledge, his is the first reported use of imprint-cytology specimens for FISH diagnosis.

Gastrointestinal stromal tumors (GISTs): CD117, DOG-1 and PKCθ expression. Is there any advantage in using several markers?

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive tract. Expression of CD117, DOG1 and PKCθ was investigated immunohistochemically in a series of 99 paraffin-embedded GISTs in order to determine the sensitivity and diagnostic value of these markers. KIT exons 9, 11, 13 and 17 and PDGFRA exons 12 and 18 were amplified by PCR and sequenced. A total of 94/99 (94%) GISTs stained positive for CD117, 81/99 (82%) for PKCθ and 90/99 (91%) for DOG-1. A significant correlation was noted between CD117 and DOG-1 expression (p=0.0001). All three markers were expressed in 74% (73/99) of GISTs. Of the five CD117-negative cases, two were PKCθ-negative/DOG1-negative and had mutations in KIT exon 11. Two were PKCθ-positive/DOG1-positive and had mutations in PDGFRA (one each in exons 12 and 18), and one was DOG1-negative/PKCθ-positive, with a PDGFRA exon 18 mutation. The most sensitive marker was CD117, followed by DOG-1 and PKCθ. Although PKCθ was less sensitive, and its staining is more challenging and difficult to interpret, the use of this marker is highly recommended, particularly in CD117-negative/DOG-1-negative GISTs.

The cadherin-catenin complex in laryngeal squamous cell carcinoma.

Abnormal Wnt signaling and impaired cell-cell adhesion due to abnormal E-cadherin and ß-catenin function have been implicated in many cancers, but have not been fully explored in laryngeal squamous cell carcinoma. In this study, ß-catenin cellular location and E-cadherin expression levels were analyzed in 16 laryngeal squamous cell carcinomas (LSCCs) (9 glottic and 7 supraglottic) and 11 samples of non-tumoral inflammatory larynx tissue, using immunohistochemical methods. All non-tumoral tissues showed equally strong membranous expression of ß-catenin, while cytoplasmic expression was found in only 3 of the 11 samples. By contrast, whereas 8/9 glottic LSCCs exhibited only membranous expression of ß-catenin, 6/7 supraglottic LSCCs displayed both membranous and cytoplasmic expression (p = 0.003). Strong E-cadherin staining was observed in 9/11 non-tumoral tissues and 7/9 glottic LSCCs, whereas 4/7 supraglottic LSCCs exhibited weak expression. Reduced membrane expression of E-cadherin and cytoplasmic retention of ß-catenin in supraglottic LSCC seems to be related with more aggressive biological behavior which has been described in clinical studies. Further research is required to clarify the involvement of ß-catenin in the mechanism associated with malignant transformation in laryngeal tissues.

Differential activation of MAPK and PI3K/AKT/mTOR pathways and IGF1R expression in gastrointestinal stromal tumors.

AIM: To characterize the differentially-activated mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K/Akt/mTOR) pathways in mutant (m) and wild-type (wt) GISTs and to investigate the role of insulin-like growth factor 1 receptor (IGF1R) expression. MATERIALS AND METHODS: Ninety-nine paraffin-embedded gastrointestinal stromal tumors (GISTs) were selected. CD117, IGF1R, phospho-ERK1/2, phospho-Akt, p70S6, eukaryotic initiation factor 4E-binding protein-1 (4EBP1) and pS6 expression were investigated using immunohistochemical methods. KIT exons 9, 11, 13 and 17 and platelet derived growth factor receptor alpha (PDGFRA) exons 12 and 18 were amplified by PCR and sequenced. RESULTS: Significant differences were found in the expression of phospho-ERK1/2 between mGISTs and wtGISTs. Complex evaluation of all PI3K/Akt/mTOR pathway markers revealed greater activation in mGISTs, particularly in PDGFRA-mutated GISTs. No significant correlation was observed between IGF1R expression and either mutational status or pathway activation. CONCLUSION: There appears to be no MAPK pathway activation in wtGISTs. Tumors harboring PDGFRA mutations tended to use the PI3K/Akt/mTOR signaling pathway. Most adult GISTs, irrespective of mutational status, displayed no IGFR1 expression; tumors positive for IGFR1 showed no preferential activation of the MAPK or AKT pathways.

The cadherin-catenin complex in nasopharyngeal carcinoma.

Abnormal Wnt signaling and impaired cell-cell adhesion due to abnormal E-cadherin and ß-catenin function have been implicated in many cancers, but have not been fully explored in nasopharyngeal carcinoma. The aim of this study was to analyze ß-Catenin cellular location and E-cadherin expression levels in nasopharyngeal carcinoma. E-cadherin expression levels were also correlated with clinical data and underlying pathology. ß-Catenin and E-cadherin expression were examined in 18 nasopharyngeal carcinoma and 7 non-tumoral inflammatory pharynx tissues using immunohistochemical methods. Patient clinical data were collected, and histological evaluation was performed by hematoxylin/eosin staining. ß-catenin was detected in membrane and cytoplasm in all cases of nasopharyngeal carcinoma, regardless of histological type; in non-tumoral tissues, however, ß-catenin was observed only in the membrane. As for E-cadherin expression levels, strong staining was observed in most non-tumoral tissues, but staining was only moderate in nasopharyngeal carcinoma tissues. E-cadherin expression was associated with ß-catenin localization, study group, metastatic disease, and patient outcomes. Reduced levels of E-cadherin protein observed in nasopharyngeal carinoma may play an important role in invasion and metastasis. Cytoplasmic ß-catenin in nasopharyngeal carcinoma may impair cell-cell adhesion, promoting invasive behavior and a metastatic tumor phenotype.

Multiple non-metastatic gastrointestinal stromal tumors. Differential features.

INTRODUCTION: gastrointestinal stromal tumors (GISTs) are specific, generally KIT (CD117)-positive, mesenchymal tumors of the digestive tract displaying KIT or PDGFRA gene mutations. Clinically, they tend to present as solitary tumors of the intestinal wall; more rarely, multiple tumors may occur in one or more organs. OBJECTIVE: to review the morphological, immunohistochemical and molecular features of multiple, non-metastatic forms of GIST. SOURCES: review of the literature on Medline, and authors own experience. CONCLUSIONS: multiples GISTs may occur in three different contexts: as spontaneous lesions (in both adults and children); due to familial GIST syndrome (autosomal dominant inheritance); or in association with specific syndromes (e.g. Carney s triad, Carney-Stratakis syndrome, type I neurofibromatosis). Outside these contexts, the existence of multiple GISTs is deemed to be the result of tumor metastasis, and therefore indicative of advanced-stage disease. Clinicians need to be aware of these variants, whose prognosis and treatment differ.

[Sequential histological and immunohistochemical assessment of proliferation and apoptotic markers during treatment of psoriasis with antitumor necrosis factor alpha (infliximab)]. / Evaluación histológica e inmunohistoquímica secuencial de marcadores de proliferación y apoptosis durante el tratamiento de la psoriasis con anti-factor de necrosis tumoral alpha (infliximab).

BACKGROUND AND OBJECTIVES: Psoriasis is an inflammatory skin disease of immunologic nature that is mediated by T-helper-1 cytokines. Clinical response to treatment with antitumor necrosis factor (TNF) alpha antibodies (infliximab) has been significant; however, the mechanisms for clearance of lesions have not been elucidated. The aim of the present study was to assess variations in the histology and expression of proliferation and apoptotic markers in sequential skin biopsies of patients with psoriasis treated with infliximab. MATERIAL AND METHODS: We studied skin biopsies (of lesioned and healthy skin) from 3 patients with extensive moderate-to-severe psoriasis (mean psoriasis area and severity index [PASI] score, 35) treated with intravenous infliximab infusions (5 mg/kg) at weeks 0, 2, and 6. Biopsies were taken on days 0, 14, and 28, and were processed for conventional histological and immunohistochemical study. The apoptotic markers used were TP53, B-cell lymphoma 2 protein, anticaspase 3, and anticaspase 8. The cell proliferation marker used was Ki67. RESULTS: Treatment with infliximab was associated with a significant clinical improvement in 3 patients (mean PASI score, 21.6 at 14 days and 13.9 at 6 weeks), which correlated with the progressive disappearance of histological lesions with a decrease in epidermal proliferation. However, apoptosis was not observed, and the samples tested negative for anticaspase antibodies. Expression of TP53 decreased 2 weeks after starting treatment, and was similar to that in normal skin at 28 days. CONCLUSIONS: Clinical and histological response of psoriasis to infliximab was not associated with a significant increase in the apoptotic markers assessed.

Loss of heterozygosity at 9q32-33 (DBC1 locus) in primary non-invasive papillary urothelial neoplasm of low malignant potential and low-grade urothelial carcinoma of the bladder and their associated normal urothelium.

Tumour recurrence has a major impact on patients with non-invasive papillary urothelial tumours of the bladder. To explore the role of DBC1 (deleted in bladder cancer 1 locus), a candidate tumour suppressor gene located at 9q32-33, as prognostic marker we have performed loss of heterozygosity (LOH) testing in 49 patients with primary papillary urothelial tumours and associated normal urothelium. Data from the 38 tumours and 11 specimens of normal urothelium that were informative in the LOH study (D9S195 marker) showed that LOH in urothelium (45.4%) but not in non-invasive tumours (60.5%) was associated with tumour recurrence (p = 0.026) but not to grade or progression. Also, tumours whose normal urothelium had LOH were larger (p = 0.020) and showed cyclin D1 over-expression (p = 0.032). Non-significant increased expression of p53, p21Waf1, apoptotic index and tumour proliferation, and decreased expression of p27Kip1 or cyclin D3 also characterized tumours whose normal urothelium had LOH. The expression of these G1-S modulators, apoptotic index and tumour proliferation was more heterogeneous in papillary urothelial tumours, irrespective of having retained heterozygosity or LOH. Also, Bax expression decreased in papillary urothelial tumours having LOH (p = 0.0473), but Bcl-2 was unrelated to LOH status. In addition, FGFR3 protein expression decreased in LOH tumours (p = 0.036) and in those having LOH in their normal urothelium (p = 0.022). FGFR3 immunohistochemical expression was validated by western blot in selected cases. The survival analysis selected LOH in normal urothelium as a marker of disease-free survival (log-rank 5.32, p = 0.021), progression-free survival (log-rank 3.97, p = 0.046) and overall survival (log-rank 4.26, p = 0.038); LOH in tumours was significant in progression-free survival (log-rank 3.83, p = 0.042). It is concluded that LOH at the DBC1 locus in normal urothelium seems to be relevant in the prognosis of non-invasive papillary tumours of the bladder via selecting cases with increased proliferation, frequent alterations of the G1-S phase modulators, and decreased FGFR3 protein expression.