The beta form of the estrogen receptor is predominantly expressed in the papillary cystic neoplasm of the pancreas

Yield of surgery in solid pseudopapillary neoplasms of the pancreas: A case series and literature review

BACKGROUND

Solid pseudopapillary neoplasms (SPN) of the pancreas represents approximately 2% of non-endocrine tumors of the pancreas. It is described in the literature as a rare and predominant tumor in young women.

AIM

To report a case series with SPN and analyzing clinical, surgical, anatomopathological characteristics, as well as the prognosis and review of literature.

METHODS

Retrospective analysis of patients undergoing surgery, with histological diagnosis of SPN between 1998 and 2018, using standardized and prospectively completed forms, performed at the Surgery Service of the Upper Digestive System at Hospital São Rafael/Rede D’Or in Salvador - BA. Review of literature through a database search in MEDLINE/PubMed of retrospective articles.

RESULTS

Fourteen female patients with the average age of 31.6 years (range min-max) were selected. Twelve patients (85.7%) were asymptomatic, being an incidental diagnosis or due to screening for other reasons. One patient had abdominal pain due to gastric compression and another patient had jaundice. The 14 patients were staged with computerized tomography or magnetic resonance imaging. None had evidence of metastasis. In 8 patients (57.1%), the tumor was in the tail and body. The average size was 6.7 cm (range min-18). The type of surgery was according to the anatomical location of the tumor. There was no lymph node involvement. In two cases, vascular resection with the use of a prosthesis was required for reconstruction. The surgical margins were free. In all cases, postoperative immunohistochemistry confirmed that it was a solid pseudo-papillary neoplasia of the pancreas. There has been no disease recurrence in any case so far.

CONCLUSION

The tumors had a benign, indolent and histopathological behavior compatible with the literature. Curative surgery is recommended in all cases.

Is the beta estradiol receptor receiving enough attention for its metabolic importance in postmenopause?

The relationship between menopause and the development of metabolic diseases is well established. In postmenopause women, there is an expansion of visceral white adipose tissue (WATv), which highly contributes to the rise of circulating lipids. Meanwhile, muscle glucose uptake decreases and hepatic glucose production increases. Consequently, in the pancreas, lipotoxicity and glycotoxicity lead to deficient insulin production. These factors initiate an energy imbalance and enhance the probability of developing cardiovascular and metabolic diseases. Although the activation of estradiol receptors (ER) has been shown to be beneficial for the WAT stock pattern, leading to the insulin-sensitive phenotype, authors have described the risk of these receptors' activation, contributing to neoplasia development. The selective activation of beta-type ER (ERβ) seems to be a promising strategy in the treatment of energy imbalance, acting on several tissues of metabolic importance and allowing an intervention with less risk for the development of estrogen-dependent neoplasia. However, the literature on the risks and benefits of selective ERβ activation still needs to increase. In this review, several aspects related to ERβ were considered, such as its physiological role in tissues of energy importance, beneficial effects, and risks of its stimulation during menopause. PubMed, SciELO, Cochrane, and Medline/Bireme databases were used in this study.

Gender difference in the transabdominal ultrasound findings of solid-pseudopapillary neoplasm

BACKGROUND

Solid-pseudopapillary neoplasm (SPN) is a rare tumour that is mostly observed in young females. However, onset in males is also observed, and they do not necessarily present with typical findings. A comparison between male and female SPN patients focusing on the ultrasound findings was performed.

METHODS

Sixteen patients including 5 males who received transabdominal ultrasounds and were diagnosed with SPN based on their resected specimens were compared by sex in terms of the following: 1) age, 2) symptoms, 3) ultrasound findings, 4) preoperative ultrasound diagnoses, and 5) histology.

RESULTS

1) The age was significantly higher in males (43 vs. 31, P = 0.004). 2) Symptoms were not observed in any of the males while 4/11 females were symptomatic (P = 0.245). 3) Tumour size was significantly smaller in males (20 mm vs. 33 mm, P = 0.014), and there was a higher percentage of cystic components in females (0% vs. 73%, P = 0.026). 4) SPN was listed as the first differential diagnosis in 9/11 females as opposed to 2/5 males (P = 0.139). 5) Cystic areas on the ultrasound corresponded to necrosis and hemorrhage. All cases showed expression of progesterone and androgen receptors regardless of sex.

CONCLUSIONS

There were significant differences between male and female SPN patients in terms of age, tumour size, and presence of cystic components. Attention should be paid to the finding that onset in males was more common from middle age onwards in comparison to females and that a cystic component was not observed.

[The histological and immunohistochemical diagnosis of solid pseudopapillary neoplasm of the pancreas and its differential diagnosis]

Solid pseudopapillary neoplasm of the pancreas is a rare tumor of uncertain histogenesis, described separately by Gruber and Frantz, that accounts for between approximately 1% and 3% of pancreatic neoplasms. It is characterized by a cystic and solid pattern of growth patterns with formation of pseudopapillae. It occurs primarily in young women, although cases in children and older patients and men have been reported. The tumor is of low-grade malignant potential, as the majority of the cases are cured by simple but complete surgical resection. Knowledge of the unique morphologic characteristics of this neoplasm is essential for the correct diagnosis. We review herein the pathologic and immunohistochemical features of this neoplasm and its differential diagnosis with other pancreatic tumors.

Generation of an estrogen receptor beta-iCre knock-in mouse

A novel knock-in mouse that expresses codon-improved Cre recombinase (iCre) under regulation of the estrogen receptor beta (Esr2) promoter was developed for conditional deletion of genes and for the spatial and/or temporal localization of Esr2 expression. ESR2 is one of two classical nuclear estrogen receptors and displays a spatiotemporal expression pattern and functions that are different from the other estrogen receptor, ESR1. A cassette was constructed that contained iCre, a polyadenylation sequence, and a neomycin selection marker. This construct was used to insert iCre in front of the endogenous start codon of the Esr2 gene of a C57BL/6J embryonic stem cell line via homologous recombination. Resulting Esr2-iCre mice were bred with ROSA26-lacZ and Ai9-RFP reporter mice to visualize cells of functional iCre expression. Strong expression was observed in the ovary, the pituitary, the interstitium of the testes, the head and tail but not body of the epididymis, skeletal muscle, the coagulation gland (anterior prostate), the lung, and the preputial gland. Additional diffuse or patchy expression was observed in the cerebrum, the hypothalamus, the heart, the adrenal gland, the colon, the bladder, and the pads of the paws. Overall, Esr2-iCre mice will serve as a novel line for conditionally ablating genes in Esr2-expressing tissues, identifying novel Esr2-expressing cells, and differentiating the functions of ESR2 and ESR1.

Natural history and malignant risk factors of solid pseudopapillary tumors of the pancreas

BACKGROUND AND AIM

Solid pseudopapillary tumors (SPTs) of the pancreas are unusual neoplasms of uncertain prognosis. Most patients with SPTs have a good prognosis after undergoing surgical resection, but there are rare cases in which a locally infiltrative growth pattern and metastatic variety are exhibited, or recurrence of the disease after surgery occurs; these cases have been reported with very poor clinical outcomes. Our study investigated the natural history of SPTs and delineated the clinicopathologic features that may predict the malignancy potential of the disease.

METHODS

A total of 100 patients with suspected SPTs were enrolled in our study and 77 patients underwent surgical resection. A resulting 60 tumors were pathologically proven to be SPTs and the affected patients were followed-up regularly after surgery. Clinical and pathologic data for all 100 patients were analyzed.

RESULTS

Of the 60 total patients with histologically positive SPTs, 55 (92%) were women and 5 (8%) were men. The median patient age was 34 years (range, 13-77 years). Among the 60 patients, 9 had malignant SPTs and 51 had benign SPTs. Deep parenchymal invasion into the surrounding tissue was the most frequent pathologic feature suggesting malignancy (75%) among the 60 patients who underwent surgical resection. Patient clinicopathologic characteristics and demographic factors were compared between those who had benign SPTs and those who had malignant SPTs. There were no significant differences in the various patient features between the 2 groups, including age, sex, symptoms, tumor size, tumor location, internal tumor composition, pattern of tumor calcification, tumor necrosis, hemorrhage, and immunohistochemical tumor tissue patterns. There were 2 patients who had distant metastasis; 1 presented with distal metastasis in the liver and the other patient had recurrence of cancer with a peritoneal mass after surgery. Metastasectomy was performed on the 2 patients and there was no mortality or disease progression during the follow-up period (median, 143 months; range, 53-319 months).

CONCLUSION

Solid pseudopapillary tumors are low-grade tumors that have a generally good prognosis. However, the clinical development and malignancy potential of SPTs are neither fully understood nor predictable, even with histologically benign tumors. Further investigations in tumor biology, along with long-term patient follow-up, may provide insight into the disease process and clinical development of SPTs.

Primary pancreatic cystic neoplasms of the pancreas revisited. Part IV: rare cystic neoplasms

Primary pancreatic cystic neoplasms are being recognized with increasing frequency due to modern imaging techniques. In addition to the more common cystic neoplasms-serous cystadenoma, primary mucinous cystic neoplasm, and intraductal papillary mucinous neoplasm-there are many other less common neoplasms that appear as cystic lesions. These cystic neoplasms include solid pseudopapillary neoplasm of the pancreas (the most common rare cystic neoplasm), cystic neuroendocrine neoplasm, cystic degeneration of otherwise solid neoplasms, and then the exceedingly rare cystic acinar cell neoplasm, intraductal tubular neoplasm, angiomatous neoplasm, lymphoepithelial cysts (not true neoplasms), and few others of mesenchymal origin. While quite rare, the pancreatic surgeon should at the least consider these unusual neoplasms in the differential diagnosis of potentially benign or malignant cystic lesions of the pancreas. Moreover, each of these unusual neoplasms has their own natural history/tumor biology and may require a different level of operative aggressiveness to obtain the optimal outcome.

Pancreatic cysts: pathologic classification, differential diagnosis, and clinical implications

CONTEXT

Cystic lesions of the pancreas are being recognized with increasing frequency and have become a more common finding in clinical practice because of the widespread use of advanced imaging modalities and the sharp drop in the mortality rate of pancreatic surgery. Consequently, in the past 2 decades, the nature of many cystic tumors in this organ has been better characterized, and significant developments have taken place in the classification and in our understanding of pancreatic cystic lesions.

OBJECTIVE

To provide an overview of the current concepts in classification, differential diagnosis, and clinical/biologic behavior of pancreatic cystic tumors.

DATA SOURCES

The authors' personal experience, based on institutional and consultation materials, combined with an analysis of the literature.

CONCLUSIONS

In contrast to solid tumors, most of which are invasive ductal adenocarcinomas with dismal prognosis, cystic lesions of the pancreas are often either benign or low-grade indolent neoplasia. However, those that are mucinous, namely, intraductal papillary mucinous neoplasms and mucinous cystic neoplasms, constitute an important category because they have well-established malignant potential, representing an adenoma-carcinoma sequence. Those that are nonmucinous such as serous tumors, congenital cysts, lymphoepithelial cysts, and squamoid cyst of pancreatic ducts have no malignant potential. Only rare nonmucinous cystic tumors that occur as a result of degenerative/necrotic changes in otherwise solid neoplasia, such as cystic ductal adenocarcinomas, cystic pancreatic endocrine neoplasia, and solid-pseudopapillary neoplasm, are also malignant and have variable degrees of aggressiveness.

Current management of cystic neoplasms of the pancreas

Over the last decade there has been a dramatic increase in the number of patients identified with pancreatic cysts. This increase has been largely attributed to advances in imaging. The majority of these cysts represent benign neoplasms; however, a significant fraction of these are pre-malignant or malignant. Because the majority of these neoplasms are benign, many reports have advocated a selective approach to surgical resection. Here we review the literature that has contributed to the development of our approach to the management of these cystic neoplasms. We provide an overview of the key features in diagnosis and in predicting malignancy. Particular attention is given to the natural history and management of intraductal papillary mucinous neoplasms (IPMN).

Expression and localization of endocrine gland-derived vascular endothelial growth factor (EG-VEGF) in human pancreas and pancreatic adenocarcinoma

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) was recently identified as the first tissue-specific angiogenic molecule. EG-VEGF (the gene product of PROK-1) appears to be expressed exclusively in steroid-producing organs such as the ovary, testis, adrenals and placenta. Since the human pancreatic cells retain steroidogenic activity, in the present study we ascertained whether this angiogenic factor is expressed in normal pancreas and pancreatic adenocarcinoma. Tissue samples from normal males (n=5), normal females (n=5) and from surgically resected adenocarcinomas (n=2) were processed for RT-PCR and immunohistochemical studies. Results from semi-quantitative analysis by RT-PCR suggest a distinct expression level for EG-VEGF in the different tissue samples. The relative amount of EG-VEGF mRNA in pancreas was more abundant in female adenocarcinoma (0.89) followed by male adenocarcinoma (0.71), than normal female (0.64) and normal male (0.38). The expression of mRNA for EG-VEGF in normal tissue was significantly higher in females than in males. All samples examined showed specific immunostaining for EG-VEGF. In male preparations, the positive labeling was localized predominantly within the pancreatic islets while in female preparations the main staining was detected towards the exocrine portion. Specific immunolabeling was also observed in endothelial cells of pancreatic blood vessels. Our data provide evidence that the human pancreas expresses the EG-VEGF, a highly specific mitogen which regulates proliferation and differentiation of the vascular endothelium. The significance of this finding could be interpreted as either, EG-VEGF is not exclusive of endocrine organs, or the pancreas should be considered as a functional steroidogenic tissue. The extent of the expression of EG-VEGF appears to have a dimorphic pattern in normal and tumoral pancreatic tissue.

Cystic lesions of the pancreas

Although cystic tumors of the pancreas are relatively rare, they constitute an increasingly important category. Advances in imaging and interventional techniques and the sharp drop in the mortality rate of pancreatic surgery have rendered pancreatic biopsies and resections commonplace specimens. Consequently, in the past two decades, the nature of many cystic tumors in this organ has been better characterized. The names of some existing entities were revised; for example, what was known as papillary-cystic tumor is now regarded as solid-pseudopapillary tumor. New entities, in particular, intraductal papillary mucinous neoplasm and its variants, such as oncocytic and intestinal subtypes were recognized. The importance of clinical and pathologic correlation in the evaluation of these lesions was appreciated, in particular, with regards to the multifocality of these lesions, their association with invasive carcinomas, and thus their 'preinvasive' nature. Consensus criteria for the distinction of these from the ordinary precursors of adenocarcinoma, the pancreatic intraepithelial neoplasia, were established. The definition of mucinous cystic neoplasms was refined; ovarian-like stroma has now become almost a requirement for the diagnosis of mucinous cystic neoplasia, and defined as such, the propensity of these tumors to occur in perimenopausal women became even more striking. The validity and clinical value of classifying the pancreatic cysts of mucinous type as adenoma, borderline, CIS and invasive have been established. Related to this, the importance of thorough sampling in accurate classification of these mucinous lesions was recognized. Greater accessibility of the pancreas afforded by improved invasive as well as noninvasive modalities has also increased the detection of otherwise clinically silent cystic tumors, which has led to the recognition of more innocuous entities such as acinar cell cystadenoma and squamoid cyst of pancreatic ducts. As the significance of the cystic lesions emerged, cystic forms of otherwise typically solid tumors were also better characterized. Thus, significant developments have taken place in the classification and our understanding of pancreatic cystic tumors in the past few years, and experience with these lesions is likely to grow exponentially in the coming years.

Solid-pseudopapillary neoplasm of the pancreas: Three cases with a literature review

Solid-pseudopapillary neoplasm of the pancreas is a very rare tumor. It most commonly occurs in young women and has unique pathologic features. Previous immunohistochemical studies demonstrated that most solid-pseudopapillary neoplasms were immunoreactive with antibodies directed against vimentin and neuron-specific enolase. Recently, expression of CD10 and CD56 in this tumor has been reported. In this report, we expanded the demographic profile, highlighting 3 cases of solid-pseudopapillary neoplasm of the pancreas that presented in an elderly woman, a young man, and a young woman and further characterized them histologically and immunophenotypically. Grossly, all 3 tumors were well circumscribed and had a variable degree of cystic formation, necrosis, and hemorrhage. Microscopically, these tumors were characterized by a pseudopapillary pattern of epithelioid cells arranged around a delicate fibrovascular core with sheets of bland epithelioid cells filling cystic spaces. Hyaline globules, cholesterol granulomas, and foamy cells were all seen to be common findings. Although these 3 tumors were strongly immunoreactive for vimentin, alpha-1-antitrypsin, alpha-1-antichymotrypsin, neuron-specific enolase, CD10, CD56, and progesterone receptor, they demonstrated only variable "positivity" for epithelial membrane antigen and broad-spectrum cytokeratin, but were being consistently nonreactive for synaptophysin, insulin, glucogon, chromogranin A, and estrogen receptor. Interestingly, 2 of the 3 tumors were S-100 protein and melanin A reactive but were nonreactive for HMB45.

Estrogen receptors in pancreatic tumors

OBJECTIVES

Although a potential role for estrogen receptors (ER) in pancreatic tumors has been debated for many years, the importance of the receptors in these neoplasms remains unknown. Even the expression of the 2 ER isoforms, ER-alpha and ER-beta, in histological subtypes of pancreatic neoplasms is controversial. The aim of the present study was to systematically review the available literature about ER expression in pancreatic tumors and to discuss the potential importance of estrogen signaling in them.

METHODS

We performed a comprehensive literature search and analyzed the results regarding ER expression in pancreatic tumors, with special emphasis on the specificity of the antibodies used for immunohistochemistry.

RESULTS

Many articles have been published investigating the expression of ERs in pancreatic tumors, but the results are inconsistent. Moreover, most studies used antibodies that detected only ER-alpha, not ER-beta. Thus, the expression pattern of ER-beta in pancreatic neoplasm remains especially unclear.

CONCLUSIONS

The lack of detailed studies evaluating the expression of both ER-alpha and ER-beta receptors using isoform-specific antibodies likely contributes to the inconsistency of published results concerning ER expression in pancreatic tumors. Available published evidence suggests that a thorough reexamination of the potential role of ERs in pancreatic neoplasms is warranted.

Expression of steroidogenic factors 1 and 2 in normal human pancreas

Orphan nuclear receptor steroidogenic factor-1 (SF-1) is crucial for development and function of steroidogenic organs. The steroidogenic factor-2 (SF-2) is an essential factor involved in cholesterol transfer and activation of promoters of steroidogenic enzymes CYP11A1, CYP17 and Steroidogenic Acute Regulatory Protein (StAR). We have previously demonstrated steroidogenic activity in pancreatic tissue. The aim of this study was to investigate the presence of SF-1 and SF-2 in human pancreas. Total RNA was extracted from normal male (five) and female (five) samples, obtained from the organs donor program. RT-PCR approach was used to analyze the expression of SF-1 and SF-2. Immunohistochemical analysis was performed for SF-1. The bands of expression were present in both male and female samples, although differential expression was observed. For both factors, the signal detected was more evident in males than in females. A similar pattern was present in the immunohistochemical study. Normal human pancreas expresses SF-1 and SF-2 factors similarly to ovary and adrenals. A distinctive characteristic is the sexually dimorphic expression of these factors. Our data provide evidence suggesting that the pancreas achieves steroidogenic activity supporting the presence of gender- and location-related differences in the expression of these steroidogenic factors.

What pharmacologists can learn from recent advances in estrogen signalling

The discovery of the second estrogen receptor (ER) in 1995 surprised many endocrinologists and resulted in some scepticism regarding its physiological importance. However, 8 years later, it is clear that the multiple actions of estrogen in the body are mediated by two receptors that, although similar, are distinct gene products with non-overlapping functions. This clear delineation of the functions of the two receptors in such a short time was made possible by the development of ER alpha and ER beta knockout mice. The distinct patterns of tissue distribution of these two receptors has heightened interest in novel estrogen targets in the body and has led to awareness of new sites for pharmacological intervention in diseases such as depression, prostate dysfunction, leukaemia, inflammatory bowel disease and colon cancer.