Pancreatic analogue solid pseudopapillary neoplasm arising in the paratesticular location. The first case report

Primary Solid Pseudopapillary Tumor of the Ovary: A Case Report and Review of the Literature

INTRODUCTION

Solid pseudopapillary neoplasms (SPNs) are rare and mainly originate from the pancreas. SPNs originating from the ovary (SPN-O) are extremely rare, and only 13 cases have been reported in the English literature since 2010.

CASE

We report a 31-year-old woman with SPN-O accompanied by multiple metastases in the abdominal cavity. The patient underwent staging surgery and cytoreduction. Furthermore, the multidisciplinary board decided on adjuvant chemotherapy with an FP regimen (fluorouracil plus cisplatin) because a microscopic metastasis was discovered in the peritoneum near the appendix. Next-generation sequencing showed some pathologic mutations of oncogenes/cancer-associated genes, including CTNNB1 and TP53. This is the fourteenth case of SPN-O and the first one to demonstrate the TP53 pathogenic mutant variant in SPN-O. The patient showed 8 months of disease-free survival until February 2024.

CONCLUSION

The combination of R0 cytoreduction with FOLFIRI chemotherapy appears to be an effective and feasible treatment option.

Contemporary Updates on Sex Cord-stromal Tumors of the Testis

Testicular sex cord-stromal tumors (TSCSTs) are relatively rare, representing ~5% of testicular neoplasms overall. Historically, TSCSTs have been classified into 3 major entities: Leydig cell tumor, Sertoli cell tumor, and granulosa cell tumor. In recent years, immunophenotypic and molecular analyses have led to a more detailed understanding of the biological and genomic features of these neoplasms, resulting in the description of new entities, some of which have been included in the latest WHO classification. This review summarizes novel histopathologic, clinical, and molecular findings that may lead to a reappraisal of established concepts and help improve the diagnosis and clinical management of TSCSTs in the coming years.

Case report: A case report and literature review of extrapancreatic solid pseudopapillary neoplasm

Background

Solid pseudopapillary neoplasm (SPN) is a rare tumor with low malignant potential, which typically occurs in the pancreas. Extrapancreatic SPN is also extremely rare worldwide.

Case presentation

We report a case of a 70-year-old woman hospitalized with abdominal pain and bloating. The patient did not have any underlying diseases, such as diabetes, coronary heart disease, or hypertension. More than 30 years ago, the patient underwent surgery for “ectopic pregnancy”. The patient had no family history of hereditary disease, nor did any immediate family members have a history of cancer. Laboratory tests showed that her hemoglobin and albumin levels were low and she had a high level of cancer antigen 125 (CA125). Enhanced computed tomography (CT) showed a large tumor in the abdomen and pelvis. The patient subsequently underwent surgery, and it was found that the tumor was attached to the terminal ileum. Pathological findings suggested that the tumor was an extrapancreatic SPN, with an ectopic pancreas found in the tumor tissue. The patient did not receive chemotherapy or radiotherapy after surgery. After 13 months of follow-up, the patient was admitted again with abdominal pain. CT showed tumor recurrence with extensive systemic metastases. The patient and her family refused reoperation and biopsy, and the patient was discharged after the abdominal pain and anemia resolved.

Conclusion

We report a rare case of extrapancreatic SPN of ileal origin, which could be the first report worldwide. It had aggressive biological features, with recurrence and metastasis 13 months after surgery. For extrapancreatic SPN, the risk of recurrence should be assessed, and for tumors suspected of malignant behavior, a longer follow-up after discharge may be needed. Although SPN generally has a good prognosis after surgery, there is no consensus on whether postoperative chemotherapy and other treatments are needed for patients with high recurrence risk.

Pancreatic Solid Pseudopapillary Neoplasm: Key Pathologic and Genetic Features

CONTEXT.—

Solid pseudopapillary neoplasm of the pancreas is a low-grade malignant tumor generally associated with a good prognosis. Solid pseudopapillary neoplasms show peculiar morphologic features, but sometimes the differential diagnosis with other pancreatic neoplasms (ie, pancreatic neuroendocrine tumors) can be a challenging task, especially in cytologic or biopsy specimens. In these cases immunohistochemistry is a useful tool, but the diagnostic utility of several proposed immunohistochemical markers is questionable. In recent years, despite several attempts to characterize the pathogenetic, molecular, and prognostic features of solid pseudopapillary neoplasms, they still remain unclear.

OBJECTIVE.—

To give the reader a comprehensive update on this entity.

DATA SOURCES.—

The PubMed database (US National Library of Medicine) was searched using the following string: pseudopapillary tumor [AND/OR] neoplasm [AND/OR] pancreas. All articles written in English were included. In addition, because a heterogeneous terminology has been used in the past to define solid pseudopapillary neoplasms, the reference lists of each paper selected in the PubMed database were also reviewed.

CONCLUSIONS.—

This review gives a comprehensive update on the pathologic, clinical, and molecular features of solid pseudopapillary neoplasms, particularly addressing issues and challenges related to diagnosis. In addition, we have tried to correlate the molecular alterations with the morphologic and clinical features.

A Morphologic and Immunohistochemical Comparison of Nuclear β-Catenin Expressing Testicular Sertoli Cell Tumors and Pancreatic Solid Pseudopapillary Neoplasms Supporting Their Continued Separate Classification

Some recent reports suggested that many Sertoli cell tumors, not otherwise specified (SCTs-NOS) of the testis were analogs of the solid pseudopapillary neoplasm (SPN) of the pancreas. One of the most relied on pieces of information for this assertion was the shared occurrence in both neoplasms of exon 3 mutations of the CTNNB1 gene, which was reflected by nuclear β-catenin expression. We, therefore, compared the morphologic and immunohistochemical features of 18 SCTs-NOS with strong, diffuse nuclear β-catenin expression with 16 SPNs that also showed such positivity. Although there were clear similarities in the light microscopic features of these neoplasms, there were also significant differences that included, in SCT-NOS and SPN, respectively: hollow tubules (53% vs. 0%), sheet-like growth (44% vs. 94%), circumscription (79% vs. 25%), corded or trabecular patterns (81% vs. 31%), formation of papillae or pseudopapillae (24% vs. 69%), growth in nests or clusters (94% vs. 50%), perivascular pseudorosettes (13% vs. 56%), and rhabdoid cytology (6% vs. 50%). Commonly shared morphologic features included signet-ring cells, pale or foamy cytoplasm, myxoid stroma, cyst formation, perivascular hyalinization, and globular or band-like basement membrane deposits. On immunohistochemical study, sex cord markers were frequently positive in SCTs-NOS (steroidogenic factor-1-94%; FOXL2-87%; SOX9-69%; calretinin-60%; Wilms tumor-1-38%; inhibin-29%) whereas all of these markers were negative in the SPNs. We conclude that even though SCT-NOS and SPN share some morphologic features and nuclear immunoreactivity for β-catenin, there remain differences, both morphologically and immunohistochemically, between these neoplasms to the degree that SCT-NOS should not be equated with pancreatic SPN.

Solid pseudopapillary neoplasm (SPN) of the testis: Comprehensive mutational analysis of 6 testicular and 8 pancreatic SPNs

BACKGROUND

Recently, we came with the theory of a possible relationship between a group of testicular and pancreatic tumors. We used one case of a pancreatic analogue solid pseudopapillary neoplasm of the testis composed partially of areas reminiscent of solid pseudopapillary neoplasm (SPN) of the pancreas and partially of structures identical to primary signet ring stromal tumor of the testis (PSRSTT) as a connecting link between these two entities. After demonstrating that PSRSTT and pancreatic analogue SPN of the testis share the same immunoprofile and genetic features characteristic for pancreatic SPN, we came to the conclusion that pancreatic analogue SPN of the testis and PSRSTT represent a morphological spectrum of a single entity and that both are related to the pancreatic SPN.

DESIGN

The aim of this study is to present a series of 6 cases of testicular tumors, which lacked the signet ring cell component and were thus morphologically very similar to the SPN of the pancreas. The goal of this study is to compare the genetic background of these testicular tumors that are obviously related to the PSRSTT/pancreatic analogue SPN of the testis with the series of 8 pancreatic SPN.

RESULTS

The mutational analysis revealed an oncogenic somatic mutation in the exon 3 of the CTNNB1 (β-catenin) gene in all analyzable (5/6) testicular and all pancreatic (8/8) tumors. The immunoprofile (positivity with β-catenin, CD10, vimentin, NSE, CD56, and negativity with inhibin, calretinin, chromogranin) was identical in all testicular and pancreatic tumors.

CONCLUSION

This study expanded the morphological spectrum of the PSRSTT/pancreatic analogue SPN of the testis by adding 6 cases without the signet ring cell component. Considering the obvious analogy of PSRSTT/pancreatic analogue SPN of the testis/SPN of the testis and their relationship to the pancreatic SPN we propose the collective term "solid pseudopapillary neoplasm of the testis" for these tumors. The mutational profile of the SPN of the testis and pancreas was the same in both groups of tumors which we consider as a final proof that SPN of the testis is identical to the SPN of the pancreas.

Solid Pseudopapillary Neoplasm of the Pancreas: Clinicopathologic Feature, Risk Factors of Malignancy, and Survival Analysis of 53 Cases from a Single Center

Introduction

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare tumor of low malignant potential. The aim of this study was designed to evaluate the clinicopathologic feature, predictive factors of malignancy, and survival from experience of a single center.

Methods

53 consecutive patients who underwent surgery for a pathologically definitive SPN were retrospectively reviewed.

Results

A total of 53 cases included 7 male cases and 46 female cases with the median age of 35.4 years (14-67). Abdominal pain and mass were the most common clinical presentations. The radiological presentations were consistent with solid and cystic pattern in 18 cases, solid pattern in 25 cases, and cystic pattern in 10 cases. The predominant location of tumor was pancreatic body and tail. The mean size of the tumors was 6.4 cm. Aggressive en bloc resection combined with organ-preserving should be indicated whenever feasible. Follow-up information was available for 48 patients with a median follow-up time of 48 months. The 5-year disease-specific survival was 95.7%. Incomplete capsule was not only the predictive factor of malignancy but also the significant predictor of disease-specific survival.

Conclusion

Incomplete capsule may suggest a malignant SPN and a prognostic indicator of disease-specific survival. We recommend that surgeons consider a more radical resection with an incomplete capsule of tumor.