Spontaneous shrinkage of a solid pseudopapillary tumor of the pancreas: CT findings

Solid pseudopapillary neoplasm of the pancreas with hepatic metastases: problems and strategies

Background

Solid pseudopapillary neoplasms of the pancreas with hepatic metastases are infrequent and difficult to diagnose, and treatment is uncertain.

Methods

A retrospective analysis of clinical data from patients with pancreatic solid pseudopapillary neoplasm (SPN) hepatic metastases who underwent surgery at the First Hospital of Jilin University from January 2005 to December 2021 was conducted. A total of 287 patients with SPN were included in the study, of which 8 (3%) developed liver metastases, all of whom were treated surgically and recovered well after surgery. The clinical presentation, imaging features, surgical treatment, histopathological examination, and postoperative follow-up data (mean 70 months; range 28-138 months) of the patients were recorded and analyzed. Clinical response strategies can be derived by reviewing previous studies on hepatic metastases of SPNs.

Results

For resectable hepatic metastases from pancreatic solid pseudopapillary neoplasms, early surgery with total resection of the primary tumor and metastasis has shown great efficiency and is associated with patient good prognosis. In patients presenting unresectable hepatic metastases, aggressive tumor reduction surgery resulted in the alleviation of clinical symptoms and reduction of tumor burden while potentially achieving long-term survival.

Conclusion

For hepatic metastases of SPNs, a preoperative liver tissue biopsy is beneficial for a definitive diagnosis. Surgery demonstrates excellent therapeutic efficacy and is considered the preferred curative treatment approach. This paper presents clinical experiences with SPN-related hepatic metastases at the Affiliated Hospital of Jilin University, which can be used to guide patient counseling in clinical practice.

Potential Role for Observation in Small Solid Pseudopapillary Neoplasm (SPN)

BACKGROUND

Solid pseudopapillary neoplasms (SPN) are rare tumors of the pancreas, typically affecting young women. Resection is the mainstay of treatment but is associated with significant morbidity and potential mortality. We explore the idea that small, localized SPN could be safely observed.

METHODS

This retrospective review of the Pancreas National Cancer Database from 2004 to 2018 identified SPN via histology code 8452.

RESULTS

A total of 994 SPNs were identified. Mean age was 36.8 ± 0.5 years, 84.9% (n = 844) were female, and most had a Charlson-Deyo Comorbidity Coefficient (CDCC) of 0-1 (96.6%, n = 960). Patients were most often staged clinically as cT2 (69.5%, n = 457) followed by cT3 (17.6%, n = 116), cT1 (11.2%, n = 74), and cT4 (1.7%, n = 11). Clinical lymph node and distant metastasis rates were 3.0 and 4.0%, respectively. Surgical resection was performed in 96.6% of patients (n = 960), most commonly partial pancreatectomy (44.3%) followed by pancreatoduodenectomy (31.3%) and total pancreatectomy (8.1%). In patients clinically staged as node (N0) and distant metastasis (M0) negative, occult pathologic lymph node involvement was found in 0% (n = 28) of patients with stage cT1 and 0.5% (n = 185) of patients with cT2 disease. The risk of occult nodal metastasis significantly increased to 8.9% (n = 61) for patients with cT3 disease. The risk further increased to 50% (n = 2) in patients with cT4 disease.

CONCLUSIONS

Herein, the specificity of excluding nodal involvement clinically is 99.5% in tumors ≤ 4 cm and 100% in tumors ≤ 2 cm. Therefore, there may be a role for close observation in patients with cT1N0 lesions to mitigate morbidity from major pancreatic resection.

Spontaneous regression in solid pseudopapillary neoplasm of pancreas

A solid pseudopapillary neoplasm (SPN) of the pancreas is a rare neoplasm that mainly occurs in young women. We herein report the case of spontaneous regression in SPN of the pancreas. A 48-years-old female was found to have a mass in the head of the pancreas on examination for her back pain and referred to our hospital in 20XX. Laboratory data showed no abnormalities in serum levels of pancreatic enzymes and tumor markers. A contrast CT scan of upper abdomen showed a slightly enhanced lesion (23 × 19 mm in diameter) without cystic component or fibrous capsule in the head of the pancreas. An MRI scan showed the mass as low-intensity in T1-WI and high-intensity in T2-WI. She admitted to our hospital for further examination of a pancreatic mass by EUS-FNA in 20XX + 4. EUS showed a slightly hypoechoic mass (30 × 19 mm in diameter) compared with the neighboring normal pancreas. Tumor margin was relatively clear and the internal echo image was homogenous. Histological findings revealed a solid and pseudopapillary proliferation of eosinophilic polygonal cells with oval nuclei. The tumor cells were positive for vimentin and CD10 in the cytoplasm and β-catenin in the nuclei, which led to the diagnosis of SPN. We recommended this patient to undergo surgical resection, however, the patient chose follow-up examinations. Follow-up study after 1 year using MRI scan showed spontaneous regression, which was coincided with her menopause. These findings suggest that the natural regression of SPN may occur and female sex hormone changes may regulate the growth of SPN.

[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.

Acute pancreatitis in children and adolescents

In this Topic Highlight, the causes, diagnosis, and treatment of acute pancreatitis in children are discussed. Acute pancreatitis should be considered during the differential diagnosis of abdominal pain in children and requires prompt treatment because it may become life-threatening. The etiology, clinical manifestations, and course of acute pancreatitis in children are often different than in adults. Therefore, the specific features of acute pancreatitis in children must be considered. The etiology of acute pancreatitis in children is often drugs, infections, trauma, or anatomic abnormalities. Diagnosis is based on clinical symptoms (such as abdominal pain and vomiting), serum pancreatic enzyme levels, and imaging studies. Several scoring systems have been proposed for the assessment of severity, which is useful for selecting treatments and predicting prognosis. The basic pathogenesis of acute pancreatitis does not greatly differ between adults and children, and the treatments for adults and children are similar. In large part, our understanding of the pathology, optimal treatment, assessment of severity, and outcome of acute pancreatitis in children is taken from the adult literature. However, we often find that the common management of adult pancreatitis is difficult to apply to children. With advances in diagnostic techniques and treatment methods, severe acute pancreatitis in children is becoming better understood and more controllable.

Solid pseudopapillary tumor of the pancreas with hepatic metastasis: spontaneous regression over 10-year follow-up period

A solid-pseudopapillary tumor (SPT) of the pancreas is known as a low grade malignant tumor with a good prognosis; therefore, surgical intervention is necessary. A 14-year-old boy presented with a large pancreatic SPT and three hepatic metastases. The patient and his family refused surgery. Two serial follow-up CT scans over a period of 13 years demonstrated almost complete disappearance of the pancreatic tumor and three hepatic metastases without relevant treatment. Although there have been a few reports of spontaneous healing of SPT, there has been no report regarding spontaneous disappearance of SPT and distant metastasis. Herein, we report on the spontaneous regression of a large SPT and the disappearance of three hepatic metastases.

Spontaneous regression of pancreatic cancer: Real or a misdiagnosis?

Spontaneous tumor regression has been subject of numerous studies and speculations for many years. This phenomenon is exceptional, but well reported, in some types of tumors, but not in pancreatic cancer. Pancreatic cancer has the worst five-year survival rate of any cancer. Despite numerous molecular studies and clinical approaches, using several mouse models, this cancer responds poorly to the existing chemotherapeutic agents and progress on treatment remains elusive. Although pancreatic cancer tumors seldom undergo spontaneous regression, and some authors take that with skepticism, there are some cases reported in the literature. However, the variability in the description of the reports and technical details could make this process susceptible to misdiagnosis. Distinguishing between different types of pancreatic carcinoma should be taken with caution as they have wide differences in malignant potential. Diseases such as pancreatic benign tumors, insulinomas, or autoimmune pancreatitis could be responsible for this misdiagnosis as a pancreatic cancer. Here we review different cases reported, their clinical characteristics, and possible mechanisms leading to spontaneous regression of pancreatic cancer. We also discuss the possibilities of misdiagnosis.