The 2015 World Health Organization Classification of lung tumors: new entities since the 2004 Classification

In the last few years different new pulmonary neoplastic lesions have been recognised and some of them, namely NUT carcinoma, PEComatous tumors, pneumocytic adenomyoepithelioma, pulmonary myxoid sarcoma, myoepithelial tumors/carcinomas entered in the last 2015-WHO classification of lung tumors. In addition angiomatoid fibrous histiocytoma and ciliated muconodular papillary tumor have been morphologically and genetically characterized albeit not yet included in the 2015-WHO classification. In the present paper we summarised the clinical, morphological, immunohistochemical and molecular features of these new entities. The knowledge of key histologic and molecular characteristics may help pathologists in achieving a correct diagnosis thus leading to an adequate therapeutic approach.

Carcinosarcoma of the Female Urethra

Carcinosarcoma is a rare malignant tumor with a biphasic morphology characterized by the presence of a malignant epithelial and mesenchymal component. It has been reported in many organs, including the genitourinary tract. We describe a case of a 47-year-old woman admitted to our hospital for history of recurrent urinary tract infection, dysuria and discharge of bloody fluid from the urethra at the end of urination. A tender palpable mass under the anterior vaginal wall was found and pathological examination showed a urethral carcinosarcoma. The histopathogenetic hypothesis and clinical management were considered in this report.

Poly (ADP-ribose) polymerase 1 protein expression in normal and neoplastic prostatic tissue

A genetic background has been implicated in the development of prostate cancer. Protein microarrays have enabled the identification of proteins, some of which associated with apoptosis, that may play a role in the development of such a tumor. Inhibition of apoptosis is a co-factor that contributes to the onset and progression of prostate cancer, though the molecular mechanisms are not entirely understood. Poly (ADP-ribose) polymerase 1 (PARP-1) gene is required for translocation of the apoptosis-inducing factor (AIF) from the mitochondria to the nucleus. Hence, it is involved in programmed cell death. Different PARP-1 gene expression has been observed in various tumors such as glioblastoma, lung, ovarian, endometrial, and skin cancers. We evaluated the expression of PARP-1 protein in prostatic cancer and normal prostate tissues by immunohistochemistry in 40 men with prostate cancer and in 37 normal men. Positive nuclear PARP-1 staining was found in all samples (normal prostate and prostate cancer tissues). No cytoplasmic staining was observed in any sample. PARP-1-positive cells resulted significantly higher in patients with prostate carcinoma compared with controls (P<0.001). PARP-1 over-expression in prostate cancer tissue compared with normal prostate suggests a greater activity of PARP-1 in these tumors. These findings suggest that PARP-1 expression in prostate cancer is an attempt to trigger apoptosis in this type of tumor similarly to what reported in other cancers.

PARP-1 protein expression in glioblastoma multiforme

One of the most common type of primary brain tumors in adults is the glioblastoma multiforme (GBM) (World Health Organization grade IV astrocytoma). It is the most common malignant and aggressive form of glioma and it is among the most lethal ones. Poly (ADP-ribose) polymerase 1 (PARP-1) gene, located to 1q42, plays an important role for the efficient maintenance of genome integrity. PARP-1 protein is required for the apoptosis-inducing factor (AIF) translocation from the mitochondria to the nucleus. PARP-1 is proteolytically cleaved at the onset of apoptosis by caspase-3. Microarray analysis of PARP-1 gene expression in more than 8,000 samples revealed that PARP-1 is more highly expressed in several types of cancer compared with the equivalent normal tissues. Overall, the most differences in PARP-1 gene expression have been observed in breast, ovarian, endometrial, lung, and skin cancers, and non-Hodgkin's lymphoma. We evaluated the expression of PARP-1 protein in normal brain tissues and primary GBM by immunohistochemistry. Positive nuclear PARP-1 staining was found in all samples with GBM, but not in normal neurons from controls (n=4) and GBM patients (n=27). No cytoplasmic staining was observed in any sample. In conclusion, PARP-1 gene is expressed in GBM. This finding may be envisioned as an attempt to trigger apoptosis in this tumor, as well as in many other malignancies. The presence of the protein exclusively at the nucleus further support the function played by this gene in genome integrity maintenance and apoptosis. Finally, PARP-1 staining may be used as GBM cell marker.

Primary high grade sarcoma of the specialised prostatic stroma: a case report with clinico-pathological considerations

Malignant tumours of the prostate other than carcinomas are rare. One such malignant tumours arising from the specialised stromal tissue of the prostate is stromal prostatic sarcoma (namely low-grade and high-grade). Herein, we report the clinico-pathological features of a high grade stromal sarcoma of the prostate occurring in a 65-year-old man who presented for urinary obstructive symptoms. The clinical picture suggested a benign prostatic hyperplasia, and surgery consisting in a transcapsular adenomectomy was performed. Following a pathological diagnosis of high grade prostatic stromal sarcoma, a radical cystoprostatectomy and bilateral pelvic node dissection was performed showing residual high grade stromal sarcoma of the prostate and incidental in situ urothelial carcinoma of the bladder. No further medical treatments were planned. One year after surgery the patient is well with no evidence of local disease or distant metastases.

Right leg swelling as primary presentation of metastatic Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare malignant cutaneous neuroendocrine tumour with an aggressive behaviour and frequent regional lymph node and distant metastases. It mostly occurs in old patients and the commonest sites are the skin of the head, neck and the extremities. Typically, the primary tumour presents as a fast-growing, painless, reddish nodule with an iceberg-like effect, broadening in the depth. Although the pathogenesis of MCC remains largely unknown, ultraviolet radiation and immunosuppression are likely to play a significant pathogenetic role. The authors describe an unusual case of MCC clinically presenting as lymphedema on the right leg due to an inguinal lymphonodal metastasis. Although extensive investigations were performed the authors were unable to discover the cutaneous primary tumor. The authors examine the etiopathogenesis and hypothesis of this rare tumour and describe the clinical differential diagnosis. They suggest that clinical features together with imaging studies and morphological and immuno-histochemical findings are important for the correct diagnosis.

Schwannoma of the epiglottis: case report focusing on clinico-pathological aspects

Laryngeal schwannomas are uncommon lesions with only few cases reported. Herein we present a further case of a schwannoma of the epiglottis, occurring in a 62-year-old with a clinical history of a cutaneous malignant melanoma and laryngeal glottic keratosis. The schwannoma was incidentally discovered as a small polypoid lesion located on the laryngeal surface of the epiglottis and was removed endoscopically. The procedure was uneventful and the patient is well six months later. Authors focus on the diagnostic and therapeutic options for this unusual lesion and discuss the differential diagnosis of the spindle cell proliferation of the larynx.

Prediction by quantitative histology of pathological stage in prostate cancer

AIMS

To find a predictor of extraprostatic extension in clinically localized prostate cancer (PCa), pre-operative ultrasound-guided prostate needle biopsies and clinico-pathological data were reviewed.

METHODS

One hundred and eighty-three consecutive patients who underwent radical retropubic prostatectomy for clinical T1-T2 PCa and serum PSA <10 ng/ml were reviewed. Pre-operative biopsy was performed according to an extended protocol and whole-mount prostatectomy specimens were processed. The following biopsy variables were categorized to this analysis: Gleason score (< or =6, >6), TPC (< or =20%; >20%), GPC (< or =50%; >50%), cancer-positive cores (< or =2; >2), cancer-positive cores in both lateral portions (yes; no), PCa (monolateral; bilateral).

RESULTS

Only 60/183 specimens showed an organ-confined PCa; the remaining ones showed pT3a in 57 cases, pT3b in 11 and pT3 with positive surgical margins in 55. A locally advanced PCa was found in 60.2 and 76.8% of T1c and T2 clinical stage, respectively. The positive predictive value and negative predictive value of biopsy findings to predict a locally advanced PCa was 89.9 and 75%, respectively. All biopsy variables associations were statistically significant; however, among these variables (non-categorized), in multivariate logistic regression analysis, only GPC was significantly associated with pathologic stage (odds ratio estimate was 1.075, 95% CI: 1.053-1.098).

CONCLUSIONS

Quantitative histology, especially GPC, seems to be helpful for pre-operative staging of PCa in patients with T1c-T2 clinical stage and PSA < 10 ng/ml.

Independent prognostic value of fascin immunoreactivity in stage I nonsmall cell lung cancer

Fascin-1, the most expressed form of fascin in vertebrate tissues, is an actin-bundling protein that induces cell membrane protrusions and increases motility of normal and transformed epithelial cells. Very few data are available on the role of this protein in nonsmall cell lung cancer (NSCLC). Two hundred and twenty patients with stage I NSCLC and long-term follow-up were evaluated immunocytochemically for fascin expression. Overall, variable fascin immunoreactivity was detected in 98% of 116 squamous cell carcinomas, in 78% of 96 adenocarcinomas, in 83% of six large cell carcinomas, and in the two adenosquamous carcinomas under study. Neoplastic emboli were commonly decorated by the antifascin antibody (P<0.001), also when the surrounding invasive carcinoma was unreactive. Fascin immunoreactivity correlated with high tumour grade (P=0.017) and, in adenocarcinomas, with high Ki-67 labelling index (P=0.021). Adenocarcinomas with a prevalent bronchiolo-alveolar in situ component were less commonly immunoreactive for fascin than invasive tumours (P=0.005). Contralateral thoracic or distant metastases were associated significantly with diffuse (>60% immunoreactive tumour cells) fascin expression in adenocarcinomas (P=0.043), and marginally with strong fascin immunostaining in squamous cell carcinomas (P=0.13). No associations were noted with any other clinicopathological variables tested. Patients with tumours showing diffuse (>60% immunoreactive neoplastic cells) and/or strong immunoreactivity for fascin had a shorter survival (P=0.006 for adenocarcinomas and P=0.026 for squamous cell carcinomas), even after multivariate analysis (P=0.014 and 0.050, respectively). The current study documents for the first time that fascin is upregulated in invasive and more aggressive NSCLC, being an independent prognostic predictor of unfavourable clinical course of the disease. Targetting the fascin pathway could be a novel therapeutic strategy of NSCLC.

CD 34 expression in chronic and neoplastic liver diseases

BACKGROUND

Capillarisation of hepatic sinusoids is a well recognized phenomen occurring in long standing liver disease, in hepatic cirrhosis as well as in hepatocellular carcinoma. To study immunohistochemically the expression and distribution of CD34 in chronic liver disease and hepatocellular carcinoma in order to evaluate the possible diagnostic implication of this marker.

METHODS

Sixty-five samples of liver tissue showing normal liver, different degrees of chronic inflammation, cirrhosis and histological features of hepatocellular adenoma and carcinoma (HCC) were included in the study. The specimens were fixed in formalin and embedded in paraffin and an immunohistochemical investigation was performed by the standard avidin-biotin-peroxidase complex method with CD34.

RESULTS

The sinusoids of normal liver showed no immunoreactivity. The sinusoids of liver affected by different degrees of chronic active hepatitis showed no or focal immunostaining for CD34; an increased immunoreactivity was observed in the periportal sinusoids of the cirrhotic nodules whereas diffuse and strong staining was observed in the overall HCC as well as in the hepatocellular adenoma tested.

CONCLUSIONS

In HCC, immunoreactivity for CD34 represents an effective method to evaluate angiogenesis and to distinguish well-differentiated HCC from non-neoplastic liver. Its role in clinical stage and prognostic evaluation needs further investigation.

Pulmonary Epithelial-Myoepithelial Tumor of Unproven Malignant Potential: Report of a Case and Review of the Literature

Epithelial-myoepithelial tumors of the lung are rare neoplasms whose biological behavior and clinical course still remain to be defined. A case of epithelial-myoepithelial tumor of the lung arising from bronchial mucosa-submucosa and occurring as a polypoid lesion of the upper left bronchus in a 47-year-old man is reported. The tumor did not infiltrate the cartilaginous wall of the bronchus and showed a biphasic histological appearance with a double layering of epithelial and myoepithelial cells. Myoepithelial spindle cells with eosinophilic cytoplasm were also observed. Mitotic figures were very rare and necrosis absent. Immunohistochemical study for epithelial and muscular markers confirmed the presence of a double-cell component in the tumor, namely epithelial and myoepithelial. The patient is alive and well, with no evidence of recurrent or metastatic disease 6 months after surgery. On the basis of the present case and the six previously reported cases, we suggest using the noncommittal term pulmonary epithelial-myoepithelial tumor of unproven malignant potential (PEMTUMP) for this type of neoplasm. In addition, we first introduce p63 as a novel marker for highlighting the myoepithelial cells of the respiratory tract and speculate on the role of these cells in the development of this unusual tumor.

Immunoreactivity for thyroid transcription factor-1 in stage I non-small cell carcinomas of the lung

Thyroid transcription factor-1 (TTF-1) is a nuclear protein regulating the transcriptional activity of lung-specific genes in the normal and neoplastic bronchioloalveolar cells. It has been implicated in the normal growth and development of the lung, and the disruption of the TTF-1 locus leads to neonatal death with pulmonary hypoplasia. We evaluated retrospectively the prevalence and clinical significance of TTF-1 immunoreactivity in 222 patients with stage I non-small cell lung carcinoma (NSCLC) with a follow-up time of at least 5 years, and we investigated its relationship with other markers of tumor growth, namely cell proliferation and angiogenesis. TTF-1 immunoreactivity was documented by using the commercially available monoclonal antibody 8G7G3/1 in 72% of 97 adenocarcinomas, 5% of 119 squamous cell carcinomas, and in the glandular component of two adenosquamous carcinomas. Four large cell carcinomas were completely unreactive. In adenocarcinomas, but not squamous cell carcinomas, TTF-1 immunoreactivity correlated significantly with microvessel density (p = 0.04) and inversely with the tumor proliferation fraction assessed by Ki-67 immunostaining (p = 0.03). Also, TTF-1-immunoreactive adenocarcinomas showed a trend for a size less than 3 cm (p = 0.08). TTF-1 expression was not related to specific growth patterns, tumor grade, or tumor cell typing. TTF-1 immunoreactivity did not significantly affect patient survival, although patients with more than 75% immunoreactive neoplastic cells showed a trend for longer overall and disease-free survival. Our findings suggest that TTF-1 could be involved in the development of small pulmonary adenocarcinomas, but it has not prognostic implications in patients with stage I NSCLC.

Striated muscle cells in non-neoplastic lung tissue: a clinicopathologic study

This study was performed to study the prevalence, origin, and clinical implication of striated muscle cells in congenital non-neoplastic lung abnormalities. Five cases of striated muscle cell proliferation within congenital non-neoplastic pulmonary abnormalities were identified from a series of 31 (16%) resected specimens obtained at King's College Hospital, London, during the period 1992 to 1998. Lung tissue was also obtained from 48 normal human fetuses and serial sections stained for the presence of striated muscle. A histologic and immunohistochemical study of the clinical cases and the fetal material was performed by using phosphotungstic acid hematoxylin staining and immunostaining for myoglobin and desmin. Striated muscle cells were identified either as a diffuse or a focal proliferation within the lung interstitia of five infants. The congenital lung anomalies were intra-abdominal pulmonary sequestration associated with congenital cystic adenomatoid malformation (CCAM), intrathoracic sequestration again with features of CCAM, an intrathoracic sequestration associated with a congenital diaphragmatic hernia, and 2 Stocker type II intrathoracic CCAMs. Striated muscle cells were not identified in any section of lung tissue derived from the fetal series. Striated muscle cells proliferation in non-neoplastic lung tissue is more common than usually reported. Although the exact origin of such cells is speculative, because it is always detected within pulmonary anomalies, a wide morphogenetic error is likely. The clinical implication of its presence has to be further defined. HUM PATHOL 31:1477-1481.

Cathepsin D is a marker of ganglion cell differentiation in the developing and neoplastic human peripheral sympathetic nervous tissues

Cathepsin D (CD) is an aspartic proteinase which has been immunolocalised in intestinal ganglion cells of human neonates and adults. The aim of the present study was to define whether CD is a reliable ganglion cell differentiation marker in routinely fixed, paraffin-embedded tissues. For this purpose, we investigated immunohistochemically the expression and distribution of CD in the developing human peripheral sympathetic nervous system (PSNS) and gastroenteric nervous system (GENS), and in childhood neuroblastic tumours (NTs; neuroblastomas, ganglioneuroblastomas and ganglioneuromas), where ganglion cells differentiate from immature neuroblastic cells. During ontogenesis, CD expression is restricted to ganglion cell lineage with a progressively more intense cytoplasmic staining, mirroring the morphological differentiation of ganglion cells with increasing gestational ages. In neoplastic tissues, CD immunoreactivity was restricted to neuroblastic cells showing morphological features of gangliocytic differentiation (differentiating neuroblastomas, ganglioneuroblastomas) as well as to neoplastic ganglion cells (ganglioneuroblastomas, ganglioneuromas). We conclude that CD is a reliable ganglion cell differentiation marker, which can be used routinely to stain developing and mature ganglion cells in formalin-fixed, paraffin-embedded tissues. Furthermore, our results indicate that CD immunoreactivity in childhood NTs recapitulates the changes during normal PSNS development, as previously reported for Bcl-2 oncoprotein, c-ErbB2, insulin-like growth factor 2 and beta2-microglobulin. This is consistent with the current view that childhood NTs exhibit gene expression profiles mirroring those occurring during PSNS ontogenesis.

CD99 immunoreactivity in gastrointestinal and pulmonary neuroendocrine tumours

Although considered a specific marker for Ewing's sarcoma/peripheral neuroectodermal tumour, the MIC2 gene product (CD99) has been immunolocalised in a variety of human tumours. The present study evaluated immunohistochemically the prevalence of CD99 expression in a series of 68 neuroendocrine tumours of different gastrointestinal and pulmonary sites. We now report on membrane and/or granular cytoplasmic immunoreactivity in 25% of these tumours, independent of their anatomical sites. In lung neuroendocrine tumours, CD99 was preferentially confined to typical carcinoids (P=0.009). A statistically significant relationship was observed between the number of CD99 positive cells but not the immunostaining patterns and the presence of local invasion and/or distant metastases (P<0.001). Moreover, there was a tendency for CD99-reactive tumours to show a reduced proliferative activity expressed by a Ki67 index of 2% (P=0.119). The number of CD99 immunoreactive cells or patterns of immunoreactivity did not correlate with the presence of associated clinical syndrome or particular hormonal immunostaining. Although the molecular basis underlying CD99 expression in neuroendocrine tumours is still poorly understood, our data suggest that CD99 may be involved in cell-to-cell adhesion of neuroendocrine tumour cells and in downregulation of their proliferative activity.

Immunocytochemical assessment of bone marrow aspirates for monitoring response to chemotherapy in small-cell lung cancer patients

Recent reports have suggested that tumour cell immunodetection in bone marrow of small-cell lung cancer patients is by far more frequent than found cytohistologically and may have clinical relevance. This study evaluates primarily the efficacy of chemotherapy as method of in vivo purging, but also the relationship of marrow involvement with survival. A total of 112 bone marrow aspirates from 30 chemo-naïve patients were stained twice using anti-NCAM antibodies, first at diagnosis and then after chemotherapy (24 patients) or at disease progression (six patients). Marrow contamination was associated with lower survival (P = 0.002), and was also detected in 7/17 patients conventionally staged as having limited disease. At multivariate analysis, marrow involvement was an independent factor of unfavourable prognosis (P = 0.033). The amount of tumour contamination, before and after chemotherapy, remained unchanged also in responders and even in the subset of patients with apparent limited disease. Following chemotherapy, bone marrow became tumour negative only in 25% of initially positive responders and in none of non-responders. Our results indicate that (i) chemotherapy is not effective in purging bone marrow even in chemo-responsive patients and (ii) a subset of patients with limited disease and negative bone marrow aspirates might have a more favourable prognosis.

Loss of heterozygosity of the long arm of chromosome 7 in follicular and anaplastic thyroid cancer, but not in papillary thyroid cancer

Papillary thyroid cancer (PTC), but neither the follicular nor the anaplastic histotype [follicular thyroid cancer (FTC), anaplastic thyroid cancer (ATC)], overexpresses simultaneously the protooncogene HGF (hepatocyte growth factor) and its receptor HGF-R (or c-met). Because 1) HGF and c-met map to chromosome 7q21 and 7q31, respectively, 2) FTC loses genetic material at multiple loci with a frequency much higher than PTC, and 3) loss of heterozygosity (LOH) on 7q has been previously found in various tumors, we tested the hypothesis that both FTC and ATC, but not PTC, could harbor LOH in segments of 7q encompassing the loci for HGF and c-met. We screened 6 normal thyroids, 10 colloid nodules, 10 follicular hyperplasias, 10 oncocytic adenomas, 10 follicular adenomas (FA), 10 FTC, 6 ATC, 12 PTC using two microsatellite markers for HGF, and two for c-met. LOH for all 4 markers was found in 100% of FTC, 100% of ATC, and (for only 1 or 2 markers) in 10-29% of FA. This is the first demonstration of an LOH that separates both FTC and ATC from PTC, in the best possible manner: 100% vs. 0%. Clearly, each of the two segments we have probed contains at least one tumor suppressor gene, whose inactivation is crucial for the establishment of the FTC (and ATC) phenotype. This loss of genetic material explains why FTC and ATC, but not PTC, fail to express both HGF and c-met. Our findings may also have immediate diagnostic application, in the context of assisting pathologists in the often difficult task of distinguishing FA from FTC.

Epithelial inclusion in axillary lymph node associated with a breast carcinoma: report of a case with a review of the literature

Since epithelial inclusions in axillary lymph nodes are rare, some diagnostic problems concerning their nature have arisen. We report a case of a cystic squamous epithelial inclusion in an axillary lymph node of a patient affected by a high grade breast carcinoma with focal squamous differentiation. Although the lesion was histologically benign, the possibility that it represents a well-differentiated squamous metastasis cannot be completely ruled out. To our knowledge, this is the first case of an epithelial lymph node inclusion associated with a breast carcinoma showing morphological evidence of squamous differentiation. Here, we discuss the diagnostic problems and give a review of the literature.

Myofibroblastoma of the breast with hemangiopericytoma-like pattern and pleomorphic lipoma-like areas. Report of a case with diagnostic and histogenetic considerations

Myofibroblastoma (MFB) of the breast is an uncommon benign spindle cell tumor which may exhibit a wide spectrum of histological features. We report an unusual case of MFB of the male breast, showing cellular areas with a hemangiopericytoma-like pattern similar to that observed in solitary fibrous tumor (SFT) and extensive fibromyxoid areas containing numerous atypical stromal cells. The association of these atypical cells with mature adipocytes and microcystic and/or myxoid degenerative changes resembled pleomorphic lipoma-like and myxoid liposarcoma-like features, respectively. To our knowledge, these peculiar morphological findings have not been previously reported in MFB of the breast. They should be recognized to avoid confusion with other mesenchymal tumors, especially with hemangiopericytoma, pleomorphic lipoma (PL), spindle-cell lipoma (SCL) and myxoid liposarcoma. A case of MFB of the breast showing morphological features also commonly seen in SFT and PL/SCL is further morphological evidence in support of the speculation that the mesenchymal tumors of the breast, also known under the terms benign spindle cell tumors, fibromas, SFTs, SCLs and MFBs, are histogenetically related lesions.

Gastric carcinoma with ovarian metastases in an adolescent

Gastric carcinoma represents only 0.05% of malignant paediatric gastrointestinal tumours. This condition is associated with a poor prognosis because its rarity and non-specificity of the symptoms usually delay its diagnosis. The authors present a 16-year-old girl with a poorly differentiated gastric carcinoma (signet-ring-cell type) with bilateral ovarian metastases who died of peritoneal carcinomatosis despite extensive surgery and chemotherapy. The epidemiological, clinical, and pathological features of gastric carcinoma in childhood are discussed.

Intra-abdominal pulmonary sequestration associated with congenital cystic adenomatoid malformation of the lung: just an unusual combination of rare pathologies?

A case of intra-abdominal pulmonary sequestration associated with histological features of congenital cystic adenomatoid malformation (CCAM) of the lung is reported. The lesion consisted of a Stocker type II CCAM in which numerous striated muscle cells were present. A review of the literature of this rare combination of congenital pulmonary anomalies is presented.

Immunohistochemical expression and distribution of alpha2beta1, alpha6beta1, alpha5beta1 integrins and their extracellular ligands, type IV collagen, laminin and fibronectin in palmar fibromatosis

Palmar fibromatosis is characterized by changes in the expression of extracellular matrix (ECM) proteins and re-organization of the interactions between cellular and extracellular compartments. We compared the expression and distribution of alpha2beta1, alpha6beta1, alpha5beta1 integrins and their corresponding extracellular ligands, type IV collagen, laminin and fibronectin in palmar fibromatosis nodules from 24 patients. Depending on the degree of cellularity and fibrosis, three different histologic phases were identified: proliferative, involutional, and residual. Immunohistochemistry revealed that only stromal cells of the highly cellular areas of both proliferative and involutional phases were myofibroblasts, as demonstrated by their cytoplasmic positivity for alpha-smooth-muscle actin. The ECM, surrounding these cells, was strongly and diffusely positive to type IV collagen, laminin and fibronectin, whereas no immunoreactivity was found in the ECM of the fibrotic and hypocellular areas of both involutional and residual phases. Immunostaining for alpha2beta1, alpha6beta1 and alpha5beta1 integrins revealed that alpha5beta1 integrin was expressed and restricted to the myofibroblast-rich cellular areas, whereas no expression was detected for alpha2beta1 and alpha6beta1 integrins. By examining serial sections, a co-localization of alpha5beta1 integrin and fibronectin was observed in the myofibroblast-rich cellular areas, indicating that, in palmar fibromatosis, a co-ordinate expression between cellular and extracellular ligand is detected only for the alpha5beta1 integrin/fibronectin complex. These findings suggest that the alpha5beta1 integrin/fibronectin complex may be involved in regulating the interactions between myofibroblasts and ECM in palmar fibromatosis.

Metanephric adenoma of the kidney: histologic, immunohistochemical and DNA content analysis study. A case report

Metanephric adenoma is an uncommon and distinct clinicopathologic entity, recently described among benign epithelial kidney tumors. The authors report a case of a metanephric adenoma in a 70-year-old man. Because of its benign clinical course, it is important to distinguish metanephric adenoma from renal cell carcinomas and adult Wilms' tumor for which it is usually mistaken. Clinical, pathologic features and diagnostic problems of the case are discussed.

Myofibroblasts and extracellular matrix glycoproteins in palmar fibromatosis

We investigated immunohistochemically the presence of myofibroblasts and their surrounding extracellular matrix (ECM) in palmar fibromatosis nodules, obtained from 30 patients. Histologically, the three following phases were identified in palmar fibromatosis nodules: proliferative, involutional, and residual. A variable association of these phases was simultaneously detected within the same nodule. In most cases (20/30), we found that involutional and residual phases coexisted, while the association of proliferative/involutional/residual and proliferative/involutional phases was observed in 8 and 2 cases, respectively. Alpha-smooth muscle actin, a reliable marker for myofibroblastic cellular phenotype, revealed that most spindle-shaped cells of cellular areas of both proliferative and involutional phases were myofibroblasts. Regardless of the predominant association of histologic phases, these findings demonstrate that a myofibroblastic cellular component is constantly found in palmar fibromatosis nodules, although its degree is variable. Immunohistochemical study of ECM showed that collagen types IV, VI, laminin, and fibronectin were strongly expressed and restricted to cellular areas of involutional and residual phases. A combined study of cellular phenotype and ECM, using consecutive sections, demonstrated that the distritubion of collagen types IV, VI, laminin, and fibronectin followed the distribution of myofibroblasts, while they were not expressed in the areas devoid of these cells. These findings suggest that interactions between myofibroblasts and these surrounding ECM glycoproteins may be involved in the pathophysiology of palmar fibromatosis.

[Peritoneal mesothelioma. A case report]

Peritoneal mesothelioma is a rare neoplasm (annual incidence: 1-2 cases per million in the general population) and forms about 10% of all mesotheliomas. The authors report a case of malignant mesothelioma of the peritoneum in a male, 61 years old. After laparotomy the patient was treated with intraperitoneal administration of cisplatin (40 mg/m2 day 1-2-3-29-30-31) and intravenous administration of mitomycin C (10 mg/m2 day 1). The renal toxicity was avoided with the GSH and with prehydration before and after administration of the cisplatin. The bone marrow toxicity was avoided with the subcutaneous administration of G-CSF (300 mg three times each week) and erythropoietin (10.000 U three times a week). After the first cycle, with the reduction of the ascites, the cisplatin was administered intravenously too. After six cycles of chemotherapy (18 months after laparotomy) the patient is alive and he has a performance status of 1 (ECOG/WHO). The chemotherapy with cisplatin and mitomycin C must be preferred to the anthracycline in all the patient with cardiologic involvement. The cisplatin administered by intracavitary route give a quick response with less systemic toxicity. A review of the literature confirms the rarity of this pathology, linked epidemiologically with exposure to asbestos, and the difficulty of the preoperative diagnosis: in fact cytologic assay and ultrasonographic and TC scan always don't permit to discover a mesothelioma. The laparotomy and the laparoscopy are useful in the P.M. for the possibility of the biopsies and the apposition of the catheters for intracavitary therapy. The response of peritoneal mesothelioma to treatment is poor. The median survival after the appearance of the symptom is less than 18 months.

Surgery and polychemotherapy of non-functional endocrine pancreatic tumors: a case report with a dramatic clinical response

Endocrine pancreatic tumors (EPT) are a rare clinical entity, representing 5% of all pancreatic tumors. Nonfunctional subtypes (NF-EPT) often present themselves at diagnosis in a locally advanced or metastatic stage. Therapeutic planning of these neoplasias is based on a multidisciplinary integration of surgery and medical treatments. The Authors describe a case of NF-EPT with massive metastatic spread after cytoreductive surgery, with impressive response to polychemotherapy with 5-fluorouracil, epirubicin and dacarbazine. The various options concerning chemotherapic treatment of these tumors are reviewed.

Retroperitoneal abscesses--rare causes and atypical manifestations: report of two cases

Retroperitoneal space abscesses are a life-threatening illness which is difficult to diagnose and treat because of both their rarity and insidious clinical manifestations. The insidious development of this illness is a challenge for all medical and surgical subspecialists. The discovery of the real source of the infection is very important but not always possible, and knowledge of the anatomy and borders of the retroperitoneal space is helpful in understanding all such atypical cases and for establishing a definitive treatment. Two cases are reported that are both characterized by rare causes, uncommon development, and atypical manifestation. The normally undefined inferior borders of some parts of the retroperitoneal space or previous retroperitoneal surgery could have been the cause of the abnormal and misleading development of the abscesses. Chronically infected organs can be the true origin of this abscess, and their discovery in a nonemergency situation is mandatory for complete surgical treatment. These cases show that knowledge of the anatomy of the retroperitoneal space is important to establish the suspicion of an abscess, to understand its manifestations, which are sometimes caused by a rare pathophysiology, and to initiate appropriate treatment.