How we treat endocrine complications of immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) are antibodies that target certain immune checkpoints (ICs), such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed death 1 (PD-1) or its ligand (PD-L1), and have emerged as a powerful new tool for oncologists. As these immune checkpoints are crucial for immunological self-tolerance, such therapies can trigger autoimmune adverse effects. Endocrine complications are among the most common, including hypophysitis, thyroid dysfunction, diabetes mellitus and primary adrenal insufficiency, while autoimmune polyendocrine syndrome type 2 (APS-2) may also present. The aim of this article is to critically appraise the literature and present (i) the biological role and function of the main ICs, (ii) the use of ICIs in the treatment of various cancer types, (iii) the endocrine complications of cancer immunotherapy with ICIs and (iv) practical recommendations for screening and management of patients with such endocrinopathies in everyday clinical practice.

Malignant progression of a pleomorphic xanthoastrocytoma in a child

Pleomorphic xanthoastrocytoma (PXA) is a recently recognized rare cerebral neoplasm that predominantly affects young patients. We report on the case of a 3-year-old boy who presented with a 2-week history of headaches and seizures. Radiological investigation revealed a lesion in the right parietal-occipital lobe. The lesion was excised and histology disclosed the presence of a PXA with anaplastic features. 1 year later follow-up magnetic resonance imaging (MRI) revealed tumor relapse. An MRI of the spine was also performed and demonstrated leptomeningeal dissemination. The patient underwent a second operation. Histology revealed that the presence of a malignant PXA with anaplastic features. The patient received radiotherapy and 9 months later on follow-up MRI a new tumor recurrence was noted. A third craniotomy was performed and the tumor removed. Histological examination revealed dedifferentiation to glioblastoma multiforme. The patient was referred to the oncology department and received chemotherapy with temozolamide. 8 months later the patient was stable without tumor recurrence. PXAs require close follow-up because of their unpredictable biological behaviour.

p53 protein expression in non-Hodgkin's lymphoma. Comparative study with the wild type p53 induced proteins mdm2 and p21/waf1

Aims-To investigate the pattern of expression of p53 protein and two wild type p53 induced proteins (mdm2 and p21/waf1) as an indirect way of assessing p53 gene status in non-Hodgkin's lymphoma.Methods-Formalin fixed, paraffin wax embedded tissue from 87 cases of nodal non-Hodgkin's lymphoma, comprising 52 high grade and 35 low grade tumours, was stained by immunohistochemistry for p53, mdm2 and p21/waf1 proteins.Results-p53, mdm2 and waf1/p21 proteins were expressed in 36/52, 21/52 and 31/52 high grade and 3/35, 21/35 and 3/35 low grade non-Hodgkin's lymphomas, respectively. Parallel p53/mdm2 protein expression was found in 23 cases (21 high grade and two low grade). These 23 cases were also positive for p21/waf1 protein expression. Discordant p53 positive/mdm2 negative protein expression was found in 16 cases (15 high grade and one low grade). Eleven (10 high grade and one low grade) of these 16 cases were p21/waf1 positive and the remaining five high grade non-Hodgkin's lymphomas were p21/waf1 negative. Mdm2 and p21/waf1 proteins were not expressed in the absence of p53 protein expression.Conclusions-p53, mdm2 and waf1/p21 protein expression is more frequently associated with aggressive histotypes of non-Hodgkin's lymphoma. Parallel expression of p53, mdm2 and p21 proteins may represent non-Hodgkin's lymphomas with a wild type p53 gene as mdm2 and p21 proteins can be induced by the wild type gene. In these cases p53 protein expression may result from stabilisation via complex formation with the mdm2 protein. This could be important in the pathogenesis of these cases as mdm2 may deregulate the p53 dependent growth suppressive pathway. Discordant p53 positive/mdm2 negative/p21 negative protein expression may represent non-Hodgkin's lymphoma with p53 gene mutations unable to activate expression of mdm2 and p21 proteins. Non-Hodgkin's lymphoma with p53 positive/mdm2 negative/p21 positive protein expression may have either wild type p53 with deregulated mdm2 gene expression or mutated p53 gene with p53 independent p21 expression.

Gastric fibrolipoma causing bleeding in a child

Gastrointestinal lipomas are uncommon benign tumors usually occurring in the colon and rarely in the stomach. We report a case of a 10-year-old boy who presented with a two-week history of epigastric abdominal pain and several episodes of melena. Gastroscopy revealed a soft, elevated, broad based, polypoid lesion on the posterior wall, without superficial erosion or ulceration. One week later the patient was readmitted with melena and hematemesis, followed by a significant drop of hematocrit levels. A laparotomy was carried out and the mass was excised. Histological findings were consistent with a submucosal gastric fibrolipoma resected IN TOTO. The clinical presentation, diagnosis and management of this condition are discussed.

Spontaneous ovulation in a true hermaphrodite with normal male phenotype and a rare 46,XX/47,XXY Klinefelter's mosaic karyotype

BACKGROUND

Most true hermaphrodite patients--characterized by the presence of both ovarian and testicular tissue--demonstrate ambiguous genitalia and are diagnosed at birth, most commonly bearing a 46,XX karyotype.

PATIENT AND METHODS

We report on a 13-year-old boy presenting with left scrotal hemorrhage. He had a left inguinal hernia, a palpable testis in the right, normal male external genitalia and significant gynecomastia. During operation, the left gonad and adjacent tissue were removed for histological examination, which revealed the presence of a normal ovary, rich in follicles and a ruptured corpus luteum, suggestive of spontaneous ovulation, with a normal ipsilateral adnexa and semi-uterus. Biopsy of the right gonad revealed a dysgenetic testicle. Endocrinological assessment postoperatively depicted high FSH, pubertal testosterone and low estradiol levels. Cytogenetic analysis in peripheral blood lymphocytes and FISH of the right gonad revealed a 46,XX (70-60%)/47,XXY (30-40%) karyotype, respectively, while molecular analysis verified the presence of SRY and azoospermia factor genes.

CONCLUSION

The importance of full histological, cytogenetic and molecular investigation and of interdisciplinary approach in every single patient with sex differentiation disorders is highlighted by this rare case of spontaneous ovulation in a true hermaphrodite with normal male external genitalia and Klinefelter mosaicism.

Diffuse intraabdominal desmoplastic small round cell tumor: a ten-year experience

BACKGROUND

Intraabdominal desmoplastic small round cell tumors (IDSRCT) are rare in children and predominantly affect male adolescents and young adults. We present our experience in the management of five children with diffuse IDSRCT, managed with aggressive chemotherapy, surgery, radiotherapy and peripheral blood stem cell transplantation.

MATERIAL AND METHODS

During the last decade five patients, four males and one female (mean age 9.6 years), with diffuse IDSRCT were managed in our department. The main symptoms were abdominal distention, vague abdominal pain, and vomiting. Three patients with inoperable tumor on admission were submitted initially to open biopsy followed by aggressive chemotherapy. Regression of the tumor was followed by a second laparotomy and radical excision of any macroscopically distinguishable masses, followed by chemotherapy. In the remaining two patients a debulking procedure was done initially, followed by chemotherapy. The accurate diagnosis of the disease was established by immunohistochemistry, additionally confirmed in the last two patients by molecular analysis.

RESULTS

Three patients who had radical excision of the tumor and adjuvant chemotherapy had recurrence after two to six months. In the remaining two patients, recurrence was evident after two and eighteen months, respectively, following debulking. In addition, one patient with recurrence received radiotherapy and two others underwent peripheral blood stem cell transplantation. All but one patient died within three years from diagnosis. The last patient, who was submitted to a debulking procedure, is still alive eight months after the operation.

CONCLUSIONS

Intrabdominal desmoplastic small round cell tumor is a highly aggressive malignancy with a very poor prognosis. Multiagent chemotherapy usually leads initially to a temporary regression of the tumor, but recurrence is the rule. Radical surgical excision, radiotherapy and peripheral blood stem cell transplantation does not seem to improve prognosis significantly. Despite all therapeutic modalities the outcome is dismal and surgical efforts can be considered only as palliative.

Bcl-2 and Bax in congenital naevi

BACKGROUND

Melanocytes represent a static component of the epidermis, and the role of apoptosis in basal melanocyte function and melanocytic tumour formation has not been fully elucidated.

OBJECTIVES

The aim of this study was to investigate the expression of Bcl-2 anti-apoptotic and Bax apoptotic proteins in congenital naevi in correlation with p-27 protein and Ki-67 proliferative index.

METHODS

Our material comprised 30 congenital naevi (eight giant) excised from children aged from 15 days to 14 years old. The immunohistochemical streptavidin-biotin method was performed on paraffin sections for the detection of Bcl-2 (cl100/D5), Bax (cl2D2) , Ki-67 (MIB-1) and p-27 (1B4) proteins with monoclonal antibodies.

RESULTS

Bcl-2 protein was detected in all cases showing a strong diffuse cytoplasmic expression in >70% of the naevocytes and was preserved in the deeper parts of the naevi. On the other hand, Bax was detected in 13 of the cases, showing a fainter cytoplasmic expression in 40-50% of the naevocytes without any particular topographic distribution. Ki-67 was detected in all cases showing a limited expression in 1-2% of the nuclei mainly in the junctional and upper dermal components. p-27 protein showed a broad diffuse nuclear expression (>70% of the nuclei) in all cases with a particular increase in the deeper parts of the naevi. Bcl-2 expression showed a parallel correlation with p-27 protein.

CONCLUSIONS

Broad Bcl-2 expression in congenital naevi suggests that suppression of apoptosis may play an important role in the maintenance of naevocytes despite the low proliferative activity.

Subcutaneous fat necrosis associated with severe hypocalcaemia in a neonate

Subcutaneous fat necrosis (SFN) of the newborn is an uncommon disorder of the adipose tissue, mostly affecting full-term or post-term newborns who experience perinatal distress. The lesions of SFN typically occur during the first six weeks of life; they are usually self-limited and no specific therapy is required. The disorder may be rarely complicated with hypercalcaemia. We present the case of a neonate with perinatal asphyxia who manifested SFN followed by hypocalcaemia instead of hypercalcaemia and a biochemical profile of pseudohypoparathyroidism four weeks after the eruption of skin lesions. The infant was treated with alfacalcidiol. Blood biochemistry was normalized within one week and serum parathyroid hormone levels declined to normal over the next two months. It is suggested that perinatal asphyxia was the common etiopathogenetic factor for the development of both SFN and pseudohypoparathyroidism.

Actinic granuloma successfully treated with acitretin

Actinic granuloma is a rare skin disorder that develops in an area of actinic elastosis. The pathogenesis of the disease is obscure but the most accepted hypothesis implicates the solar radiation as the triggering factor. Typically the disease presents in middle-aged individuals with significant past sun-exposure and involves mainly the sun-exposed skin. It manifests as asymptomatic annular patches with elevated borders and central atrophy and shows little tendency to regression. Several treatments have been tried with variable success. We present a 74-year-old male who consulted our department for annular atrophic plaques involving his forehead and nose, present for 8 months and insidiously spreading but otherwise asymptomatic. A biopsy confirmed the clinical suspicion of actinic granuloma and excluded other possibilities. Our patient was commenced on acitretin 25 mg/day and showed a remarkable improvement within a year; the lesions stopped spreading and almost disappeared.

Low serum insulin values in children with multiple lesions of granuloma annulare: a prospective study

BACKGROUND

The relationship between granuloma annularae (GA) and diabetes mellitus (DM) is controversial.

OBJECTIVE

To investigate the relationship between multiple lesions of GA and carbohydrate metabolism in children.

SUBJECTS AND METHODS

Fifteen children (seven boys, eight girls, mean age 4.8 years) with five or more lesions of GA were evaluated. A personal and family history of DM or other autoimmune diseases was obtained and the glycaemic and insulin response during an oral glucose tolerance test (OGTT) was determined. Thirteen children with a negative personal and family history of DM served as controls for the OGTT and 100 other children as 'clinical controls'.

RESULTS

At the 30-min sampling of the OGTT the mean insulin values were comparable in GA children and controls (P=0.1), while the mean glucose values were significantly higher in GA children than in controls (P=0.005). All other insulin values during the OGTT were significantly lower in GA children than in controls, while all other glucose values were comparable in GA children and controls with all indices applied. Eleven out of 15 GA children had a positive family history of DM (73.3% vs. 16% of the clinical controls; P<0.0001).

CONCLUSION

Multiple lesions of GA in children are associated with significantly lower serum insulin values than in controls and mildly impaired glucose tolerance.

Desmoplastic infantile ganglioglioma: MRI and histological findings case report

Desmoplastic infantile gangliogliomas (DIG) are rare intracranial tumors occurring during the 1st year of life. They arise invariably in the supratentorial region and have a great size at presentation, commonly involving more than one lobe. They are composed of a solid peripheral component of variable size, which involves the superficial cerebral cortex and the leptomeninges, and a large cystic part. Despite the great size at presentation and occasional mitotic activity in the variable undifferentiated component, this entity constitutes a distinct clinicopathological entity with benign prognosis. We hereby present the MRI and histological findings of two cases of DIG in infants aged 9 and 10 months, respectively.

Kinetics of quiescent cord blood stem/progenitor cells with high proliferative potential in stem-cell expansion culture

BACKGROUND

The most primitive engrafting hematopoietic stem cell (HSC) resides mainly in a tumor growth factor-beta (TGF-beta)-dependent quiescent phase of the cell cycle. In this study, ex vivo expansion of UC blood (UCB) HSCs has been investigated, with the aim of showing whether quiescent HSCs can be recovered from expansion culture.

METHODS

AC133(+) stem/progenitor cells from six full term-pregnancies UCB-samples were immunomagnetically selected, followed by ex vivo expansion culture in the presence of thrombopoietin (TPO), c-kit ligand (KL), flt-3 ligand (FL) and IL-6. Quiescent HSCs were detected by a clonogenic assay that allows the detection of multipotent and committed single- lineage quiescent stem/progenitor cells, named mHPP-Q and cHPP-Q, respectively, by means of a TGF-beta blocking Ab.

RESULTS

Expansion culture of fresh selected AC133(+) cells for 1 week caused maintenance rather than expansion of mHPP-Q cells and a 1-fold increase in cHPP-Q cells. A further week culture initiated with 7-day expanded AC133(+) cells resulted in an additional 1.5-fold expansion of cHPP-Q while no mHPP-Q cells could be detected. Amplification of cHPP-Q cells in long-term expansion cultures initiated with 14-day expanded AC133(+) cells was observed for at least a further 4 weeks.

DISCUSSION

A small proportion of HPP-Q cells recovered from 7-day expansion cultures retain their multilineage potential: longer culturing of these cells results in the loss of multilineage potential while they maintain quiescent behavior and high proliferative potential.

Increased cell apoptosis in bone marrow trephine biopsies and immunomagnetically isolated myeloid progenitor cells in patients with chronic idiopathic neutropenia

The frequency of apoptotic cells in bone marrow trephine biopsies and cytospins of immunomagnetically isolated myeloid progenitor cells was determined in 39 patients with chronic idiopathic neutropenia (CIN) and 12 hematologically normal individuals using the in situ end-labeling (ISEL) apoptosis detection method. We found that 66.7% of the patients but none of the normal controls displayed apoptotic cells equal to or higher than 5% of the total mononuclear cells in bone marrow biopsies (p<0.01). In the double stain, we also found that the proportion of apoptotic CD15(+) myeloid precursor cells did not differ significantly between patients and control subjects, while the proportion of apoptotic CD34(+) hemopoietic cells could not be estimated with accuracy because of the presence of CD34(+) endothelial cells. Significantly increased apoptosis was noted in cytospins of immunomagnetically isolated patient CD34(+) and CD34(+)/CD33(+) cells but not CD34(-)/CD33(+) cells, compared to the controls ( p<0.001, p<0.02 and p>0.05, respectively). These findings confirm and extend our previous observations in flow-cytometric studies of apoptosis in CIN, indicating that increased apoptosis in CIN bone marrow concerns mainly the CD34(+) and CD34(+)/CD33(+) progenitor cell compartments. We conclude that the accelerated apoptosis in these compartments may account for the impaired neutrophil production in CIN patients.

Immunohistochemical expression of caspase-3 as an adverse indicator of the clinical outcome in human breast cancer

OBJECTIVE

Tumor growth is the net result of cell proliferation and cell loss by apoptosis. Caspase-3 (CPP32) has been considered as most directly correlated with apoptosis because of its location in the protease cascade pathway. The aim of this study was to examine the relation of the immunohistochemical expression of caspase-3 in 137 infiltrating breast carcinomas to patients' clinicopathological parameters and survival.

METHOD

A polyclonal antibody against caspase-3 was applied using a standard immunohistochemical procedure to paraffin sections.

RESULTS

By comparison with nonneoplastic breast tissue, caspase-3 appeared to be upregulated in malignant breast tissue, and its overexpression status was detected in 75.2% of the specimens. Significant statistical correlations were observed between overexpression of caspase-3 and low nuclear grade (p = 0.048), lack of p53 protein accumulation (p = 0.039), bcl-2-positive immunostaining (p = 0.027), as well as tissue inhibitor of metalloproteinase-2 immunoreactivity of neoplastic (p = 0.012) and stromal cells (p = 0.0001). Despite the above correlations, multivariate analysis revealed a significant negative influence of caspase-3 expression on patients' overall survival (p = 0.029).

CONCLUSIONS

Caspase-3 protein overexpression appears to be involved in the apoptotic pathways influenced by wild-type p53 and bcl-2 proteins. Moreover, the results show that caspase-3 overexpression in breast cancer cells seems to exert an independent adverse effect on patients' overall survival.

Peripheral primitive neuroectodermal tumour during pregnancy

The case of a 25-year-old primipara in the second trimester of pregnancy, suffering from a peripheral primitive neuroectodermal tumour (pPNET) diagnosed by bone biopsy, is described. External irradiation was initially performed because of Jacksonian seizures due to a lesion in the right cerebral hemisphere. Appropriate shielding was used to reduce fetal exposure during brain radiotherapy. Caesarian delivery at the 27th week of gestation was performed because of tumour progression. The neonate had no evidence of disease and survived for 1 month. However, the placenta and ovaries showed metastases from the maternal pPNET. The patient died 14 months after initial diagnosis owing to the aggressiveness of the tumour, the rapid and extensive semination (bone marrow, lung, liver, craniospinal axis involvement) and the inability to adequately treat the patient with appropriate doses of chemotherapy.

Cerebellar granulocytic sarcoma in an infant with CD56+ acute monoblastic leukemia

Granulocytic sarcoma (GS) is a form of extramedullary leukaemia (EML). The presence of the neural cell adhesion molecule (NCAM) on the surface of the blasts, which is recognized by the CD56 monoclonal antibody, enhances their propensity for tissue penetration. GS within the central nervous system (CNS), in particular within the cerebellum, is extremely uncommon. We review the literature and describe an infant with isolated cerebellar GS relapse, which antedated a CD56+ acute monoblastic leukaemia bone marrow (BM) relapse.

Immunohistochemical expression of p53, p21/waf1, rb, p16, cyclin D1, p27, Ki67, cyclin A, cyclin B1, bcl2, bax and bak proteins and apoptotic index in normal thymus

The immunohistochemical expression of p53, p21, Rb, p16, cyclin D1, Ki67, cyclin A, cyclin B1, p27, bcl2, bax, and bak proteins and the apoptotic index (Al) were investigated in 20 normal thymuses (8 adults, 3 adolescents, 5 infants and 4 newborns). The expressions of Rb, Ki67, cyclin A and cyclin B1 were overlapping, being high in the cortex with a tendency for decreased expression toward the medulla. Apoptotic cells were mainly detected in the cortex and the corticomedullary junction, rarely being present in Hassall's corpuscles. The mean values of Ki67, cyclin A, and cyclin B1 expression in thymuses were 77.2%, 32.2% and 21.4% (newborns), 62.4%, 33.7% and 18.5% (infants), 56.9%, 23.4% and 18.9% (adolescents) and 38.7%, 21.7% and 14.6% (adults), respectively. The mean values of AI in thymuses from newborns, infants, adolescents and adults were 1.4%, 2.9%, 2.7% and 3.8%, respectively. This decrease in proliferation and increase in apoptosis may account for the process of thymic involution. P16 expression was widespread with most of Hassall's corpuscles being p16-positive. P16-positive cells and Hassall's corpuscles increased with the increase in age, in keeping with the suggested role of p16 in cellular senescence. P27 expression was undetectable in subcapsular thymocytes with a tendency for increased expression toward the medulla. The expressions of Ki67, cyclin A and cyclin B1 were inversly related with that of p27, consistent with previous evidence that p27 concentration is reduced when the cell-cycle progresses. P21 and much less frequently p53 proteins were mainly detected in a part of the subcapsular cortical epithelial cells. These findings suggest that a) in thymocytes, the apoptotic pathway is mostly p53-independent and the function of p21 as a negative regulator of the cell cycle must be redundant to other negative regulators, such as p16 and p27 which were abundantly detected in thymocytes and b) in some thymic epithelial cells, the p21 expression may be induced by p53, but in most of them seems to be p53-independent. Most of Hassall's corpuscles were p21-positive, consistent with previous evidence that these structures represent end stages of maturation of thymic medullary epithelium and that p21 protein is involved in the process of terminal differentiation. Cyclin D1 positivity was found in some macrophages. Bcl2 expression was mainly seen in medullary thymocytes, reflecting the surviving thymocytes in this region. The expressions of Bax and bak were more widespread in both the medulla and cortex, suggesting that these proteins play a broader role than bcl2 in the regulation of thymic apoptosis.

[Bilateral paraganglioma of the vagus nerve]

Paragangliomas are rare, usually benign tumours of the head and neck region, located along the cranial nerves and the big vessels. Vagus paraganglioma represents less than 3% of all cases of paragangliomas of the head and neck. Approximately 10% of vagus paragangliomas are presented as bilateral masses. We present the case of 75 year old female with bilateral paraganglioma, and papillary cancer of the thyroid gland at the time of diagnosis. Diagnostic and therapeutic procedures are discussed with special regard to possible complications.

Extranodal cytotoxic T-cell lymphoma in a patient with X-linked agammaglobulinaemia

This report documents the occurrence of an extranodal cytotoxic peripheral T-cell lymphoma (PTCL) in a patient with X-linked agammaglobulinaemia (XLA). The diagnosis was based on the immunohistochemical detection of T-cell antigens and of the cytotoxic proteins TIA1 and Granzyme B in the tumour cells. This report provides further evidence that cytotoxic lymphomas are part of the differential diagnosis of neoplasia in patients with immunodeficiencies.

Immunohistochemical expression of the p53, mdm2, p21/Waf-1, Rb, p16, Ki67, cyclin D1, cyclin A and cyclin B1 proteins and apoptotic index in T-cell lymphomas

Fifty-seven cases of T-cell lymphomas (TCL) including 5 lymphoblastic (T-LBL) and 52 peripheral TCL (PTCL) were analyzed by immunohistochemistry for the expression of p53, mdm2, p21, Rb, cyclin D1, cyclin A, cyclin B1, and Ki67/MIB1 proteins and 39/52 PTCL were also analyzed for the expression of p16 protein and for the presence of apoptotic cells by the TUNEL method. The aim was to search for abnormal immunoprofiles of p53 and Rb growth control pathways and to determine the proliferative activity and the apoptotic index of TCL. Abnormal overexpression of p53, p21 and mdm2, in comparison to normal lymph nodes, was found in 12/57, 10/57 and 2/57 cases of TCL, respectively. Abnormal loss of Rb and p16 expression was found in 1/57 and 2/39 cases, respectively, whereas abnormal overexpression of cyclin D1 was not detected in any of the 57 cases. Our data revealed entity-related p53/p21/mdm2 phenotypes. Indeed, most nodal and cutaneous CD30+ anaplastic large cell lymphomas (ALCL) showed concomitant overexpression of p53 and p21 proteins (7/8 cases), and mdm2 was overexpressed in 2 p53-positive nodal ALCL. In contrast, overexpression of p53 was found in 3/17 cases of nodal peripheral TCL unspecified (PTCL-UC) and 2/7 non-ALCL cutaneous pleomorphic TCL. Overexpression of p21 protein was detected in 2/3 p53-positive PTCL-UC and in 1/2 p53-positive non-ALCL cutaneous pleomorphic TCL. Finally, all the remaining 25 cases of TCL did not show p53 and p21 overexpression. Overall, the p53+/p21+ phenotype in 10/57 TCL suggests wild-type p53 capable of inducing p21 expression. The highest apoptotic index (AI) was found in ALCL and a positive correlation between apoptotic index and Ki67 index (p<0.001) was detected. Ki67, cyclin A and cyclin B1 expression was found in all 57 TCL and on the basis of the combined use of these 3 variables, 3 groups of proliferative activity could be determined: a) high in ALCL and T-LBL, b) low in mycosis fungoides (MF) and gammadelta hepatosplenic TCL, and c) intermediate in the remaining TCL entities. The proliferative activity in the 12 p53 overexpressing cases was higher in comparison to the 45 p53-negative cases. Ki67 expresion in more than 25% of tumour cells showed significant correlation with p53 overexpression (p<0.001). Rb expression tended to be parallel to Ki67, cyclin A and cyclin B1 expression in all but one case of nodal PTCL-UC which displayed loss of RB expression. Interestingly, this case was p53-negative, whereas the p53-positive cases were Rb-positive. These findings suggest that different pathogenetic routes may function in some TCL, involving either the p53 or, less frequently, the Rb pathways.

Co-existence of cutaneous true histiocytic lymphoma with refractory anaemia: report of a case

The case of a 70-year-old man with refractory anaemia who developed cutaneous true histiocytic lymphoma two years after diagnosis, is described. Whether this association is a simple coincidence or indicates some etiopathogenetic relationship between these two unrelated disorders is unknown and needs the analysis of more cases.

Immunohistochemical expression of the p53, p21/Waf-1, Rb, p16 and Ki67 proteins in multiple myeloma

The aim of this study was to investigate the immunohistochemical expression of the proteins p53, Waf-l/p21, Rb, p16 and Ki67 in 38 cases of multiple myelomas (MM) and 4 cases of solitary extramedullary plasmacytomas in relation to the tumor histological grade and stage. In bone marrow (BM) biopsies from MM, overexpression of p53 and p21 proteins, in comparison to plasma cell infiltrates in non-pathological bone marrow, was detected in 13 out of 38 and 21 out of 38 cases, respectively. The combined immunoexpression of p53 and p21 proteins in the 38 cases of MM showed the following patterns: a) p53+/p21+ (13 cases) b) p53-/p21+ (8 cases) and c) p53-/p21- (17 cases). Rb, p16 and Ki67 proteins were detected in tumor cells in all 38 cases and their expression increased proportionally to tumor grade. The 4 cases of solitary extramedullary plasmacytomas showed the p53+/p21+ pattern in 2 cases and the p53-/p21+ pattern in 2 cases, all of them displaying Rb, p16 and Ki67 expression in tumor cells. The pattern p53+/p21+ might represent cases with wild-type p53 able to induce p21 expression. However, in previous studies p53 mutations were reported in about 3-10% of MM, and they were strongly associated with advanced disease. Thus, in some p53+/p21+ cases associated with high p53 expression and advanced disease, p53 gene cannot be excluded and up-regulation of p21 expression may be p53- independent. P53 overexpression correlated with increased tumor grade (p < 0.005), advanced histological stage (p < 0.001) and Ki67 expression in more than 10% of tumor cells (p < 0.001). Since increase in Ki67 expression also correlated with increased tumor grade (p < 0.001) and advanced histological stage (p < 0.001), these findings suggest that impairment of the p53 growth control pathway is associated with tumor progression in MM. Thus, p53 and Ki67 immunostaining in routine BM biopsies may be helpful for the detection of MM with potentially aggressive behavior. Overexpression of p21 in MM correlated with higher Ki67 expression (p < 0.005), suggesting that the p21 function of arresting cell-cycle is impaired. Ki-67 expression in MM increased in parallel with p16 (p < 0.001) and Rb expression (p < 0.001). Rb expression could represent a growth control response which, however, might not be able to induce growth arrest in view of the parallel increase in Ki67 expression and of previous findings showing that Rb protein in MM cells is expressed mostly in its phosphorylated form.

Morphologically defined myeloid cell compartments, lymphocyte subpopulations, and histological findings of bone marrow in patients with nonimmune chronic idiopathic neutropenia of adults

This report describes the morphologically defined myeloid cell compartments, lymphocyte subpopulations, and histological findings of bone marrow in 38 patients with nonimmune chronic idiopathic neutropenia of adults (NI-CINA) and in 14 controls. We found that patients had a striking shift to the left of the granulocytic series due to both an increased proportion of proliferating cells and a reduced proportion of maturating cells compared with controls (P<0.001 and P<0.001, respectively). Individual proportions of these cells strongly correlated with the number of circulating neutrophils (r = -0.462, P < 0.01 and r = 0.495, P<0.01, respectively). However, in the great majority of patients (78.9%), no significant changes in marrow cellularity or the myeloid to erythroid cell ratio could be demonstrated. Patients also had increased proportions of CD19+B cells, CD20+B cells, and plasma cells with polytypic expression relative to controls (P < 0.02, P< 0.01, and P< 0.001, respectively). Individual values of plasma cells were inversely correlated with the number of blood neutrophils (r=-0.414, P<0.01). Dispersed bcl-2+lymphocytic aggregates without germinal centers were seen in about one-third of the patients. T cells and natural killer (NK) cells did not show any significant change. Patients had increased proportions of CD57+, CD16+, and HLA-DR+ cells and, in a few cases, increased proportions of histiocytes and eosinophils. CD45RO+ cells were reduced only in patients with pronounced neutropenia. Expression of p53 protein has not been detected in any cell population. With the exception of some megaloblastoid features of erythroid lineage seen in two patients and the presence of some micromegacaryocytes seen in two others, no significant morphological abnormalities were noted. All of these findings are consistent with our previously reported suggestion for the possible existence of an underlying low-grade chronic inflammatory process in NI-CINA patients, which may be involved in the pathogenesis of neutropenia in the affected subjects.

Retractile mesenteritis presenting as fever of unknown origin and autoimmune haemolytic anaemia

Retractile mesenteritis is an extremely rare disease characterised by a non-specific inflammatory and fibrotic process of the mesenteric adipose tissue, which is usually accompanied by pain and a variety of other abdominal symptoms. We describe here the case of a patient with retractile mesenteritis presenting with prolonged high-grade fever and autoimmune haemolytic anaemia without abdominal symptoms. The patient's illness was complicated by chylous ascites. Diagnosis was suspected by computed tomography and confirmed histologically following exploratory laparotomy. The patient was treated with prednisone and azathioprine, and he had a rapid improvement in anaemia and fever relief, but no substantial change in the mesenteric lesions. Our case adds autoimmune haemolytic anaemia to the wide spectrum of manifestations of retractile mesenteritis and implies the possible involvement of immune mechanisms in the pathogenesis of the disease.

Expression of p53, p21/waf1, bcl-2, bax, Rb and Ki67 proteins in Hodgkin's lymphomas

The aim was to investigate the combined immunoexpression of p53, p21, bcl-2, bax, Rb and Ki67 proteins in Hodgkin's lymphomas (HL) and correlate expression patterns with the histotype and the Epstein-Barr Virus (EBV) status. Paraffin-sections from 56 cases of HL (18 nodular sclerosis and 38 mixed cellularity) and from ten "reactive" lymph nodes were investigated. P53, p21, bcl-2, bax, Rb and Ki67 proteins were detected in Hodgkin and Reed-Sternberg (HRS) cells in 35/56, 56/56, 24/56, 23/56, 56/56 and 56/56 cases of HL, respectively. No correlation was found between the expression of each protein and the EBV status or the histotype of HL. Comparison between p53 and p21 staining revealed two patterns: a) p53+/p21+ (35 cases); and b) p53-/p21+ (21 cases). The pattern p53+/p21+ suggests wild type p53 protein able to induce the expression of p21 while the p53-/p21+ pattern suggests p53-independent p21 expression. These results are consistent with the interpretation that inactivating p53 gene mutations may be rare in HL. Comparison between bcl-2 and bax staining showed a statistically significant relationship (p<0.001) for coexpression (19 cases) or absence of expression of both proteins (28 cases) in HRS cells. In contrast, bax expression was observed in most lymphoid cells in all "reactive" lymph nodes. Since the proapoptotic bax protein may act as tumour suppressor it is possible that the absence of this protein in HRS cells in a substantial proportion of HL may confer growth advantage and play a role in their pathogenesis. This could suggest bax gene alterations in some HL since in other studies acute lymphoblastic leukaemia cell lines demonstrate bax gene mutations with loss of bax immunoexpression. Another possibility is that reduced bax expression may be due to post transcriptional regulation, as was described in lymphoma cell lines. Comparison between Rb and Ki67 staining disclosed two main deviations from the normal parallel relationship in reactive lymph nodes: a) 2 cases with low Rb and high Ki67 expression possibly reflecting loss of Rb expression due to chromosome loss or to other abnormalities in the structure or the expression of Rb gene; and b) 9 cases with high RB and low Ki67 possible reflecting an attempt of Rb protein in excess to induce cell cycle arrest. Taken together, our findings provide combined immunohistological evidence for deregulated expression of cell-cycle and apoptosis-related proteins, that may play a role in the pathogenesis of HL.

CT evaluation of mesenteric panniculitis: prevalence and associated diseases

OBJECTIVE

This study was undertaken to assess the prevalence of mesenteric panniculitis on CT and to describe its appearance and associated diseases.

SUBJECTS AND METHODS

A total of 7620 consecutive abdominal CT examinations were prospectively evaluated for features common to mesenteric panniculitis such as a well-delineated inhomogeneous hyperattenuated fatty mass at the mesenteric root, envelopment of mesenteric vessels, and no evidence of invasion of the adjacent small-bowel loops that may be displaced.

RESULTS

CT findings of mesenteric panniculitis were seen in 49 patients (0.6%). We found a female predominance. Mesenteric panniculitis coexisted with malignancy in 34 patients and with benign disorders in 11 patients. In the remaining four patients, mesenteric panniculitis, verified on histology, was considered to be responsible for the patients' clinical manifestations; no other abnormality was identified. Soft-tissue nodules (n = 39) and a fatty halo surrounding vessels and nodules (n = 42) were observed in most patients. Follow-up abdominal CT examinations in 29 of the 49 patients showed changes in only one patient.

CONCLUSION

CT findings of mesenteric panniculitis may be seen in patients undergoing abdominal CT for various symptoms.

Epstein-Barr virus-associated high-grade anaplastic plasmacytoma in a renal transplant patient

Allograft transplant patients have an increased risk of developing polyclonal or monoclonal lymphoproliferative disorders, but high-grade anaplastic plasmacytomas are extremely rare in these patients. We present a renal transplant patient who developed multiple extramedullary high-grade anaplastic plasmacytomas in the oral cavity, the left maxillary antrum, the scalp, the thigh and the upper abdominal wall with no evidence of diffuse bone marrow infiltration. Epstein-Barr virus (EBV) mRNA transcripts were detected within the myeloma cells by in situ hybridization using EBER1-2 probes. Following discontinuation of immunosuppression applied, the patient was treated with a cyclophosphamide-prednisone regimen followed by local irradiation, and a complete remission was achieved within four weeks. We concluded that EBV-associated high-grade anaplastic plasmacytomas constitute one more type of post-transplant lymphoproliferative disorder, and that despite their characterization as highly malignant neoplasms, their clinical behavior is not always aggressive.

Immunohistochemical detection of p53, mdm2, waf1/p21, and Ki67 proteins in bone marrow biopsies in myelodysplastic syndroms, acute myelogenous leukaemias and chronic myeloproliferative disorders

The aim oof this study was to investigate the immunohistochemical expression of p53, mdm2, and waf1/p21 proteins in myelodysplastic syndromes (MDS), acute myelogenous leukaemias (AML), and chronic myeloproliferative disorders (CMPD). Paraffin-sections of bone marrow biopsies from 30 cases of MDS (6 cases of RAEB and RAEB-T) 22 AML (4 cases occurring in the setting of MDS), 16 chronic myeloproliferative disorders (CMPD), and 10 cases without alterations were investigated by immunohistochemistry for p53, waf1/p21, mdm2 and Ki67 proteins. P53 was detected in immature myeloid cells in 6/30 MDS (20%) and in 6/22 AML (27%) while it was not expressed in CMPD. Of the 6 p53 positive AML, 3 occurred as evolution of MDS and 3 were de novo acute leukaemias. Waf1/p21 was detected in 5/22 (23%) AML in immature myeloid cells. Waf1/p21 was also expressed in 18/30 (60%) MDS and 10/16 (63%) CMPD in variable proportion (5-25%) of the mature myeloid cells and megakaryocytes. Waf1/p21 was not detected in immature myeloid cells in MDS and CMPD. Mdm2 protein was expressed in 3/30 (10%) MDS in the immature myeloid cells and in 1/22 AML in blastic cells. The combined immunophenotypes of immature myeloid cells of MDS were: p53+/mdm2+/waf1-: 3, p53+/mdm2-/waf1-: 3, while the immunohistochemical patterns of AML were: p53+/mdm2-/waf1-: 4, p53+/mdm2+/waf1+: 1, p53+/mdm2-/waf1+: 1, p53-/mdm2-/waf1+: 3. Ki67/MIB1 staining was found in at least 30% of immature myeloid cells in MDS and AML and in at least 20% of these cells in CMPD. In conclusion, our results indicate that p53 protein is overexpressed in the myeloid lineage in a proportion of AML and MDS, while is not detected in CMPD and normal bone marrow, p53 expression was much more frequent in AML occurring as an evolution of MDS than in de novo AML. The combined immunophenotypes of p53 positive AML and MDS suggest that p53 overexpression may be due to mutation, in some AML and MDS cases with the p53+/mdm2-/waf1- phenotype. However, it would be also possible that p53 protein accumulation is not related to p53 mutation but to inhibition of p53/mdm2 binding due to mdm2 defects and/or other events related to cell stress signals. On the other hand, waf1/p21 protein overexpression without p53 expression in some AML could be p53-independent and may represent an attempt to control the high proliferation rate which was evidenced by Ki67/MIB1 immunostaining. However, the possibility of p21 to arrest cell-cycle, in these cases of AML, seems to be overridden, suggesting that cell-cycle deregulation may be involved in a proportion of AML.

Expression of p53, p21/waf, bcl-2, bax, Rb and Ki67 proteins in colorectal adenocarcinomas

This study investigated the combined immunoexpression of p53, p21, bcl-2, bax, Rb and Ki67 proteins in colorectal adenocarcinomas and correlated expression patterns with tumour stage and grade. Paraffin sections from 98 cases of colorectal adenocarcinomas were stained by immunohistochemistry for p53, p21, bcl-2, bax, Rb and MIB-1 (Ki67) proteins. In addition, 12 cases of colorectal adenomas and normal colorectal mucosa were studied in parallel. P53, p21, bcl-2, bax, Rb and Ki67 proteins were detected in at least 5% of tumour cells in 63/98, 72/98, 52/98, 96/98 and 98/98 adenocarcinomas, respectively. Comparative study of the normal-adenoma-carcinoma tissues revealed abrogation of the normal immunotopography in adenomas and adenocarcinomas, and considerable modifications, increase or reduction, of the expression of p53, p21, bcl-2, bax, Rb and Ki67 proteins in adenocarcinomas when compared with normal mucosa and adenomas. Statistically significant correlations were found between low bax expression and Dukes C stage of carcinomas, Ki67 expression and carcinoma grade, and Ki67 and Rb expression. P53, p21, bcl-2 and Rb immunoexpression did not correlate with tumour stage or grade. Our findings show that low bax immunoexpression is frequently related to colorectal adenocarcinomas with lymph node metastases suggesting that low levels of bax expression play a role in late stage colorectal cancer. The correlation between Ki67 and Rb expression, in view of previous data that the hyperphosphorylated inactive Rb protein is frequently increased in colorectal adenocarcinomas, suggests that Rb protein is somewhat ineffective in inhibiting the cell-cycle progression in these malignancies. Furthermore, our findings provide immunohistochemical evidence that the abrogation of the normal immunotopography and the modifications of the expression of p53, p21, bcl-2, bax, Rb and Ki67 proteins reflect important events in colorectal oncogenesis.

Cytotoxic protein expression in non-Hodgkin's lymphomas and Hodgkin's disease

Recent studies have shown that some peripheral T-cell lymphomas (PTCL) could be derived from lymphocytes with cytotoxic potential. Therefore, we have investigated by immunohistochemistry 34 cases of PTCL including 2 cases of hepatosplenic gamma delta PTCL and 5 cases of sinonasal NK-cell lymphomas as well as 7 cases of T-lymphoblastic lymphomas (T-LBL) for the expression of the cytotoxic proteins TIA-1 and granzyme B. In addition, 50 cases of Hodgkin's disease (HD) were investigated in order to see if these cytotoxic proteins are expressed by Hodgkin and Reed-Sternberg (HRS) cells. Expression of the TIA-1 is characteristic of cytotoxic cells regardless of their activation status whereas expression of granzymes is highly increased in activated cytotoxic cells. All the five cases of sinonasal NK-cell lymphomas expressed TIA-1 and granzyme B in most tumour cells. The two gamma delta PTCL cases expressed TIA-1 protein in most tumour cells but not granzyme B. Of the 32 other PTCL, 9 cases showed cytotoxic protein expression in tumour cells. These cases comprised 2 pleomorphic medium large cell (PML) (1 nodal and 1 intestinal) and 7 CD30 positive anaplastic large cell lymphomas (ALCL) (5 nodal and 2 cutaneous). Cytotoxic protein expression in our series appeared to be related to the location since 10/18 (55%) extranodal PTCL and NK-NHL and only 6/21 (28%) nodal PTCL expressed TIA-1, and related to histology since, in nodal PTCL, this pattern was observed in most anaplastic (5/6 cases) and in a few pleomorphic (1/9 cases) lymphomas, but not in AILD-type NHL (0/6 cases). The 7 cases of T-LBL did not express cytotoxic proteins in tumour cells. EBV was detected by EBER RNA in situ hybridization (RISH) in tumour cells in all 5 sinonasal NK-NHL and in scattered atypical cells in all 6 cases of AILD. Two of the 50 cases of HD weakly expressed TIA-1 and granzyme B in a proportion of HRS cells. EBV was detected by RISH in 19/50 cases of HD but no correlation was found between EBV status and expression of cytotoxic proteins in HRS cells. However, the finding that granzyme B positive cells were found very rarely in close vicinity of HRS cells suggests that the function of activated cytotoxic cells is locally inhibited by the HRS cells and/or the reactive cells in the vicinity of HRS cells. Taken together our data suggest that: a) sinonasal NK-cell NHL represent tumours of activated cytotoxic NK-cells, b) the hepatosplenic gamma delta PTCL represent tumours of nonactivated cytotoxic gamma delta T-cells, c) a small proportion of other PTCL, mostly anaplastic large cell lymphomas represent tumours of cytotoxic T-cells and d) only very few cases of HD expressing cytotoxic proteins in a proportion of tumour cells, could be derived from activated cytotoxic cells.

Bcl-2 protein expression in acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma

Bcl-2 protein blocks apoptosis and is involved in human intrahepatic bile-duct development. Formalin-fixed, paraffin-embedded archival tissue from 42 HBV and HCV hepatitis [20 acute AH, 22 chronic hepatitis (CH)], 12 active cirrhosis (CR) and 20 hepatocellular carcinoma (HCC) was immunostained for bcl-2 protein. In all cases, bcl-2 protein was detected in portal and intralobular lymphocytes but not in hepatocytes or Kupffer cells. Bcl-2 was positive in the cytoplasm of small portal bile ducts of chronic hepatitis, while it was strongly expressed in newly formed bile-ductules of the limiting plate, mainly in CH with marked activity and CR. Bcl-2 was detected in small bile ducts in only one case of acute hepatitis and was not detected in any case of HCC. Bcl-2 seems to be involved in the regulation of growth and apoptosis of cholangiolar cells. Its expression in small bile ducts and in newly-formed ductules especially in CH with marked activity and CR, implies that the embryonic model of intrahepatic bile duct development may be recapitulated in chronic hepatic disease. Moreover, it supports evidence for the existence of the controversial long-lived stem population in the liver. Bcl-2 does not seem to be involved in hepatocarcinogenesis.

Congenital capillary hemangioma and its therapeutic approach in infants: a case report

Hemangiomas, common congenital lesions in infants and children, are thought to arise when islands of angioblastic tissue fail to connect with the developing vascular system. They are not usually life-threatening. A case of congenital capillary hemangioma in an infant, which was surgically excised, is reported, and therapeutic approaches are discussed.

Expression of p53, p21, mdm2, Rb, bax and Ki67 proteins in lymphomas of the mucosa-associated lymphoid (MALT) tissue

We have investigated by immunohistochemistry 38 cases of B-cell MALT-NHL comprising 23 high grade (HG) and 15 low grade-(LG) tumours for the expression of p53, mdm2, p21, Rb, Ki67, bcl2 and Bax proteins. P53, mdm2 and p21 proteins were found in at least 5% of the tumour cells in 13/23, 2/23 and 11/23 HG tumours, respectively. These proteins were detected in very rare tumour cells in LG tumours. The following patterns were recorded in HG tumours: p53+/p21+/mdm2+ (2 cases), p53+/p21+/mdm2- (7 cases), p53+/p21-/mdm2- (4 cases), p53-/p21-/mdm2- (18 cases) and p53-/p21+/mdm2-(2 cases). Proliferative Ki67 index and Rb protein expression were higher in HG than in LG MALT-NHL. Bcl2 protein was expressed in all LG MALT-NHL, whereas only 2/23 HG MALT-NHL were bcl2 positive in most tumour cells. Bax protein was expressed in all MALT-NHL with HG tumours being positive in higher proportion of tumour cells than LG tumours. These findings show that significant expression of p53, mdm2, p21,Ki67 and Rb proteins occurs more frequently in aggressive histotypes of MALT-NHL. The parallel Rb/Ki67 expression suggests that Rb protein expression in MALT-NHL is normally regulated in relation to the proliferative growth fraction of the tumours. The pattern p53+/p21+/mdm2 +/- may represent MALT-NHL with wild type (wt) p53 gene since mdm2 and p21 proteins are inducible by wt p53 gene. The pattern p53+/mdm2-/p21-may represent MALT-NHL with p53 gene mutations unable to activate expression of mdm2 and p21 proteins. MALT-NHL with the p53-/mdm2-/p21 + pattern may be consistent with p53-independent p21 expression. Bax protein expression in all MALT-NHL suggests a role for this protein in the pathogenesis of these tumours.

Low-malignant potential epithelial tumors of the ovary: a clinicopathological study

Low-malignant potential (LMP) epithelial tumors of the ovary are a group which occupy an intermediate position between the benign and those of the frankly malignant ovarian neoplasms. The actual incidence, present age and treatment are still being discussed. During the period 1991-1996, from the 650 ovarian tumors which were diagnosed and treated in our institution, 401 were epithelial tumors. The LMP serous epithelial tumors consisted of 4.36% of all serous tumors while LMP mucinous tumors were 9.70% of all mucinous tumors. The LMP serous tumors had an 8 cm diameter on average, 83% were unilocular and 76.5% unilateral. The LMP mucinous tumors had a 17 cm diameter on average, 95% were multilocular and 95% unilateral. The mean age at diagnosis was 39 years for LMP serous tumors and 48 years for LMP mucinous tumors.

Immunohistochemical detection of bcl2, p53, mdm2 and p21/waf1 proteins in small-cell lung carcinomas

Thirty-one cases of small cell lung carcinomas (SCLC) were investigated by immunohistochemistry for the expression of bcl-2. P53 and the wild-type (wt) p53-induced proteins mdm2 and p21/waf1. Bcl-2 protein was detected in 24/31 cases of SCLC(77%) and p53 protein in 13/31 cases (42%). No correlation was found between histological subtype of SCLC and bcl-2 or p53 expression. Comparison between bcl-2 and p53 expression showed that 14/31 cases (45%) were only bcl-2 positive, 3/31 (11%) were only p53 positive, 10/31 (32%) were positive for both proteins and 4/31 (13%) were negative for both proteins. Mdm2 protein was detected in 2/32 SCLC which were also p53 positive. P21 protein was detected in 6/32 SCLC. Four of the p21 positive SCLC were negative for both p53 and mdm2, and two were positive for both p53 and mdm2 proteins. The significant expression of bcl-2 protein in SCLC suggests that bcl-2 may be involved in the pathogenesis of most SCLC by inhibiting apoptosis during neoplastic transformation. The expression of p53 protein in SCLC is likely to be related to underlying p53 gene mutations since these genetic alterations are very frequent in SCLC. This can be supported by our findings that 11/13 p53 positive SCLC were mdm2 and p21 negative. The two cases with p53+/mdm2+/p21+ phenotype may represent tumours with wt p53 gene and p53 protein immunoexpression due to binding to mdm2 protein. The four cases with p53-/mdm2-/p21+ phenotype may represent tumours with p53-independent p21 protein expression. Coexpression of p53 and bcl-2 proteins in a proportion of SCLC suggests that in these tumours p53 does not maintain its suppressive effect on bcl-2 expression as has been reported in vitro. Further studies at the DNA and RNA level are required to clarify the involvement of bcl-2, p53, mdm2 and wafl genes in SCLC pathogenesis.

Immunohistochemical detection of bcl2, p53, mdm2 and p21/waf1 proteins in small-cell lung carcinomas

Thirty-one cases of small cell lung carcinomas (SCLC) were investigated by immunohistochemistry for the expression of bcl-2, p53 and the wild-type (wt) p53- induced proteins mdm2 and p21/waf1. Bcl-2 protein was detected in 24/31 cases of SCLC(77%) and p53 protein in 13/31 cases (42%). No correlation was found between histological subtype of SCLC and bcl-2 or p53 expression. Comparison between bcl-2 and p53 expression showed that 14/31 cases (45%) were only bcl-2 positive, 3/31 (11%) were only p53 positive, 10/31 (32%) were positive for both proteins and 4/31 (13%) were negative for both proteins. Mdm2 protein was detected in 2/32 SCLC which were also p53 positive. P21 protein was detected in 6/32 SCLC. Four of the p21 positive SCLC were negative for both p53 and mdm2, and two were positive for both p53 and mdm2 proteins. The significant expression of bcl-2 protein in SCLC suggests that bcl-2 may be involved in the pathogenesis of most SCLC by inhibiting apoptosis during neoplastic transformation. The expression of p53 protein in SCLC is likely to be related to underlying p53 gene mutations since these genetic alterations are very frequent in SCLC. This can be supported by our findings that 11/13 p53 positive SCLC were mdm2 and p21 negative. The two cases with p53+/mdm2+/p21+ phenotype may represent tumours with wt p53 gene and p53 protein immunoexpression due to binding to mdm2 protein. The four cases with p53-/mdm2-/p21+ phenotype may represent tumours with p53-independent p21 protein expression. Coexpression of p53 and bcl-2 proteins in a proportion of SCLC suggests that in these tumours p53 doses not maintain its suppressive effect on bcl-2 expression as it has been reported in vitro. Further studies at DNA and RNA level are required to clarify the involvement of bcl-2, p53, mdm2 and waf1 genes in SCLC pathogenesis.

The value of proliferating cell nuclear antigen (PCNA)/cyclin in the assessment of cell proliferation in glomerulonephritis

Proliferating cell nuclear antigen (PCNA)/cyclin is an acidic nuclear protein increasing from the late G1 to S phases of the cell cycle and whose detection parallels other standard methods for assessing cell proliferation. The aim of this study was to investigate PCNA expression in normal and diseased human kidneys, in order to clarify cell proliferation in renal tissue and to define a possible correlation of its expression with various types of glomerulonephritis (GN). The immunohistochemical avidin-biotin complex (ABC) method was used for the demonstration of PCNA applying the monoclonal antibody PC-10 to paraffin sections from: 10 normal kidneys, 55 renal biopsies with various types of proliferative GN (PGN), 44 renal biopsies with various types of non proliferative GN (NPGN). In PCNA-positive renal biopsies with GN the antigen showed a heterogenous nuclear expression in occasional or few mesangial and glomerular epithelial cells as well as in a greater number of tubular epithelial cells. PCNA was expressed in 20% of normal kidneys and in 38% of renal biopsies with GN. The frequency of PCNA expression was significantly increased in the cases of PGN (47%) compared to that observed in the cases of NPGN (27%) (p = 0.03). PCNA was detected in 10/24 cases of IgA nephropathy, in 3/4 cases of IgM nephropathy, in 5/14 of other types of primary PGN and in 8/13 of secondary PGN. PCNA expression was not correlated with the degree of mesangial cellularity in PGN. Moreover, there was no significant difference in PCNA expression between primary and secondary PGN. PCNA demonstrated an intense expression in the majority of epithelial cells forming cellular crescents in 8/11 cases of PGN. In conclusion, PCNA was observed more frequently in diseased than in normal kidneys. The significant increase in the frequency of PCNA intraglomerular expression in PGN suggests that PCNA has a certain value in the assessment of mesangial proliferation. Moreover, the increased PCNA expression in tubular epithelial cells especially in PGN, indicates their proliferative state and may be correlated with their proposed activation and role in the progression of renal injury.

P21/waf1 protein expression in nasopharyngeal carcinoma. Comparative study with PCNA, p53 and MDM-2 protein expression

We investigated the immunohistochemical expression of p21/waf1 protein in 59 cases of nasopharyngeal carcinomas (NPC) and compared p21 expression with PCNA, p53 and mdm2 protein expression. We found p21, PCNA, p53 and mdm2 in 59/59, 59/59, 18/59 and 12/59 nasopharyngeal carcinomas, respectively. We observed a tendency to a relationship between high expression of PCNA (> 25% positivity in tumour cells) and low expression of p21 protein. Parallel p53/p21 protein expression was found in 18 cases. Twelve were also mdm2 positive. This pattern may represent NPC with wild type (wt) p53 since mdm2 and p21 proteins are inducible by wt p53 gene. In these cases p53 protein expression may be due to stabilisation to mdm2 protein. This could be important in the pathogenesis of these cases since mdm2 may deregulate the p53-dependent growth suppressive pathway. Discordant p53-/p21+ protein expression was found in 41 cases. All were also mdm2 negative. This pattern suggests immunohistochemically undetectable wt p53 gene which is able to induce p21 protein expression.

Immunohistochemical expression of p53, bcl-2, mdm2 and waf1/p21 proteins in colorectal adenocarcinomas

The present study was undertaken to examine the distribution of p53, p21, mdm-2 and bcl-2 protein expression in human colorectal adenocarcinomas in order to obtain combined information about the immunophenotypes characterising these tumours. Formalin-fixed, paraffin-embedded tissue sections from 52 cases of colorectal adenocarcinomas were stained using immunohistochemical methods for the detection of p53, p21/waf1, mdm2 and bcl-2 proteins. P53, p21/waf1, mdm2 and bcl-2 proteins were expressed in 35/52, 45/52, 9/52 and 27/52 cases, respectively. All nine mdm2+ cases expressed p53 and p21 proteins as well. The three patterns observed in p53/p21 expression were: p53+/p21+, p53+/p21- and p53-/p21+ in 28, 7, and 17 cases, respectively. Consequently, p53+/mdm2-/p21+, p53+/mdm-/p21- and p53-/mdm2-/p21+ immunophenotypes were expressed in 19, 7, and 17 cases respectively. Four patterns of p53/bcl2 expression were identified: p53+/bcl2+, 20 cases; p53+/bcl2-, 15 cases; p53-/bcl2+, 7 cases; p53-/bcl2-, 10 cases. It was noteworthy that 9 of the 10 p53-/bcl2-tumours had negative lymph node status. The present results suggest that both p53 dependent and p53-independent induction of p21 expression may be involved in the molecular mechanisms controlling these tumours. High expression of the p53 protein in colorectal carcinomas could be due not only to p53 gene mutations but also to binding to mdm2 protein which leads to p53 protein stabilisation. In addition, tumours with p53-/bcl2- immunophenotype are frequently associated to negative lymph node status and seem to be less aggressive.