Diagnosis and surgical management of a rare neoplastic entity: Solid Pseudopapillary Neoplasm of the Pancreas

Abstract

Introduction and importance

Solid Pseudopapillary Tumors of the Pancreas is an extremely rare pancreatic neoplastic entity that makes up barely 3 % of all types of exocrine pancreatic neoplasia. Symptoms vary and none of them are specific or pathognomonic for the disease. Therefore, delayed treatment or misdiagnoses could be the result. In turn, patients' morbidity and mortality significantly rise. Diagnosing or suspecting this type of critical type of neoplasia in the preoperative phase is a key component to performing appropriate and curative surgical interventions that result in increased patient survivability.

Case presentation

We hereby present the rare case of a previously healthy 20-year-old female whose chief complaints were chronic epigastric and left hypochondriac region pain and discomfort along with loss of appetite. During our preoperative radiological investigation, we found a cystic mass with well-defined borders located between the head of the pancreas and the second part of the duodenum. It measured (63 × 45 mm). No metastasis or lymph node involvement was elicited.

Clinical discussion

The tumor was utterly resected via a successful Whipple procedure. A definitive diagnosis of a Solid Pseudopapillary Tumor was reached following meticulous histopathological and immunohistochemical analysis of the resected specimens.

Conclusion

Based on our review of the published literature, no previously published cases from our country of pancreatic Solid Pseudopapillary Tumors exist. Documentation of this rare neoplasia is warranted to raise awareness and to establish the necessary clinical protocols to optimally diagnose, timely treat, and adequately follow up on patients who present with this malignancy.

Highlights

• •Pancreatic Solid Pseudopapillary Tumor is a rare tumor that makes up 0.9–2.7 % of all exocrine pancreatic neoplasia.
• •The young female population is the most vulnerable group where the female-to-male occurrence ratio is 10:1.
• •Chiefly, the patients are asymptomatic. Otherwise, they present with a gradually growing abdominal mass and jaundice.
• •The treatment of choice for Solid Pseudopapillary Tumors is complete and meticulous surgical resection.
• •To the best of our knowledge, no previous cases from our country of pancreatic SPTs were documented in the literature.

Abbreviations

SPT

Solid Pseudopapillary Tumor

CT

Computed Tomography

H&E

Hematoxylin and Eosin

IHC

Immunohistochemistry

1. Introduction

Solid Pseudopapillary Tumor (SPT) of the Pancreas is an extremely rare pancreatic neoplastic entity that comprises merely 3 % of all types of exocrine pancreatic neoplasia [1], [2]. It is estimated that >90 % of cases occur in young females with an average age range of 20-to-30 years [2], [3], [4]. SPTs are classified as low-grade malignancies that consist of epithelial cells that combine to form solid pseudopapillary structural components [5]. Their pathophysiological origin remains vaguely understood. On one hand, several hypotheses proposed that SPTs arise from primordial multipotent cells. On the other hand, other hypotheses suggest an origin that is extra-pancreatic in location [6].

Regarding the ethnic epidemiology of SPTs, African American and Asian females are often predisposed. Furthermore, the female-to-male predominance ratio is 10:1 with an average age of clinical presentation of 22 years.

Chiefly, the clinical course is unremarkable as patients are asymptomatic. Otherwise, they present with the chief complaint of a gradually growing abdominal mass and rarely, jaundice [7].

The work has been reported in line with the SCARE criteria and the revised 2020 SCARE guidelines [8].

2. Presentation of case

We present the case of a previously healthy 20-year-old female who presented to our General Surgery department complaining of chronic abdominal pain. Symptoms began 2 years prior with sudden and colicky abdominal pain. It was felt in the epigastric and left hypochondriac regions and had no radiation to other body regions. The patient estimated its severity at 05/10 on the pain scale and denied any triggers behind it. The pain was not associated with any accompanying symptoms and was partially relieved by over-the-counter analgesia.

Six months prior to the presentation, she began feeling a vague epigastric discomfort and reported a significant loss of appetite.

Relevant associated symptoms, such as skin discoloration, pallor, jaundice, nausea, emesis, alterations in bowel and genitourinary habits, fever, night and cold sweats, unintentional weight loss, history of trauma, history of previous similar incidences, history of exposure to arsenic compounds or radio−/chemotherapy were all denied.

Her surgical and gynecological histories were unremarkable.

The patient's medical, family, allergic, psychosocial, history of previous similar incidence, and history of recent infections were all negative.

The patient's Body Mass Index was 18 Kg/m².

The patient's examination was initiated via physical assessment as the vital signs were measured and yielded normal results.

Beginning with inspection, the patient's abdomen was symmetrical, moved harmoniously with respiration, no bulging -especially in the epigastric and left hypochondriac regions-, and no skin discolorations, pallor, jaundice, or hypo-/hyperpigmentation were seen.

Upon superficial and deep palpation, the abdomen was soft and lax, no tenderness or guarding were elicited, and no masses were palpated. Additionally, no remarkable findings were revealed during percussion and auscultation.

We carried out a comprehensive laboratory panel as part of our preoperative assessment. The results of which were all within normal values.

Endoscopic ultrasound was done. It revealed a nonhomogeneous hypoechoic ovoid mass measuring (50 × 60 mm) with well-demarcated borders. It is comprised of multi-cystic segments and pushed the duodenum to the right. Suggested differential diagnoses include gastrointestinal, pancreatic, and retroperitoneal tumors.

Our patient underwent a high-resolution Computed Tomography (CT) scan of the abdomen and pelvis. It demonstrated a cystic mass with well-demarcated borders situated between the pancreatic head and the second part of the duodenum. It measured (63 × 45 mm). Its contents were heterogenous without calcifications (Fig. 1A–B).

Fig. 1.

(A–B): Cross-sectional view of the preoperative CT scan of the abdomen and pelvis demonstrating a cystic mass (Orange Arrow) with well-defined borders situated between the head of the pancreas and the second part of the duodenum. It measures (63 × 45 mm). Its contents were heterogenous without calcifications. No signs of lymphadenopathy or tumor metastasis are seen.

No lymphadenopathy was seen, and no signs of metastasis were identified.

During the preoperative patient optimization stage, we prepared her by initiating and maintaining a nil-per-mouth status, setting up two large-bore intravenous access cannulas, and intravenous administration of preoperative antibiotics.

We encountered no remarkable challenges during any of the perioperative phases.

Therapeutic surgical intervention was warranted to completely remove this lesion. It was accomplished in the form of a classic Whipple procedure.

We successfully carried out the operation under general anesthesia in our tertiary university hospital under the direct guidance and mentorship of our General Surgery professor who has 36 years of experience. In addition to two primary surgical assistants with 5 years of experience, each. No perioperative complications were encountered.

Through a vertical midline incision to the abdomen, optimal exposure of the field was achieved.

The cystic mass was clearly visualized as it was located at the head of the pancreas and locally compressed the nearby duodenal segment to the right side (Fig. 2A–B).

Fig. 2.

(A–B): Intraoperative image during surgical exploration and isolation of the mass prior to resection. It depicts the pancreas with its tumor (Blue Arrow). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Treatment was in the form of a Whipple procedure where we resected the distal segment of the stomach, duodenum, pancreatic head and neck, common bile duct, gallbladder, achieved a gastrojejunostomy, cholangiojejunostomy, and pancreatojejunostomy.

The surgically resected specimens (Fig. 3) were immediately sent to our specialized histopathology lab to undergo the proper analysis to reach a definitive diagnosis.

Fig. 3.

Intraoperative image after surgical resection showing the excised mass.

Histopathological analysis through Hematoxylin and Eosin (H&E) staining demonstrated that the tumor was in the head of the Pancreas. It measured (55 mm) in diameter. No angioinvasion was marked and the ampulla, bile duct, duodenum, stomach, pancreatic line of resection, other lines of resection, and lymph nodes were all free of tumor involvement (Fig. 4A–D). All lines of resection were free of neoplastic involvement and no malignant seeding was detected in the accompanying lymph nodes.

Fig. 4.

A: Histopathological analysis of the resected mass via H&E (×40 magnification) revealing a well-defined solid and cystic pancreatic neoplasm surrounded by a fibrous pseudo-capsule.

B: Histopathological analysis of the resected mass via H&E (×200 magnification) revealing pseudo-papillae that consist of delicate vascular core surrounded by uniform tumor cells showing eosinophilic cytoplasm, uniform nuclei with fine chromatin, and inconspicuous nucleoli. Small aggregates of foamy macrophages noted in-between the pseudo-papillae.

(C—D): Histopathological analysis of the resected mass via H&E (×100 magnification) revealing a heterogenous neoplasm that consists of variable admixture of solid and pseudopapillary/cystic areas. The intervening stroma is distinctly hyalinized.

It was necessary to further perform microscopic analysis via Immunohistochemistry (IHC). The excised specimens stained negative for (CD99, CK7, and Synaptophysin) and the Ki-67 proliferative index was <1 % (Fig. 5A–B).

Fig. 5.

A: Histopathological analysis via IHC (×400 magnification) showing negative staining for CK7.

B: Histopathological analysis via IHC (×400 magnification) showing Ki-67 very low proliferative index <1 %.

Postoperatively, consistent sterile wound dressings were applied, adequate hydration by intravenous fluids was provided, proper prophylactic antibiotics were administered, and suitable analgesics were prescribed.

Our patient was discharged within 5 days of her surgical intervention and has been followed up for 9 months thus far. It is worth noting that the entirety of the patient's symptoms subsided after surgery.

She was registered for a regular clinical surveillance schedule that consisted of physical and radiological examination to ensure her successful recovery and to check the possible recurrence or relapse. All the previous examinations yielded normal results. Furthermore, we referred the patient to our specialized oncology clinic for the necessary follow-up from an oncological standpoint.

3. Discussion

Solid Pseudopapillary Neoplasm is a profoundly rare tumor class. They are estimated to constitute 0.9 %–2.7 % of all types of pancreatic exocrine tumors and only 5 % of cystic pancreatic tumors [2], [5].

Principally, the age of patients affected by SPTs ranges from 2-to-85 years of age [2]. The young female population is the most affected group where the female-to-male occurrence ratio is 10:1 [2].

Clinically, the course of this malignancy is in 38.1 % of cases asymptomatic in nature [9]. Nevertheless, most patients have an eventful clinical course. Common symptoms patients present with are abdominal pain, unintentional weight loss, anorexia, general fatigue, nausea, emesis, fever, abdominal mass, and jaundice [2], [9], [10]. Symptoms associated with disease metastasis also occur because of organ tumor involvement. Distant metastasis takes place in approximately 7.7 %, whereas lymph node metastasis is seen in merely 1.6 % of cases, respectively [9].

To diagnose SPTs, a CT scan could provide support in this endeavor. SPTs typically appear on CT imaging as well-defined heterogeneous lesions that are characterized by variable cystic and solid features. Solid portions of the tumor are predominantly located in the periphery, while cystic components are typically located in the center. Furthermore, calcifications can be marked in both the periphery and the center [11], [12].

The treatment of choice for SPTs is complete and meticulous surgical resection [2], [9].

A Cochrane systematic review was done to compare two surgical intervention directions: Pylorus-preserving pancreaticoduodenectomy vs. classic Whipple procedure. The results revealed no major variations exist between the two procedures in terms of postsurgical mortality rate, overall patient survival, and morbidity [13].

Via histopathological analysis, SPTs are neoplasia that microscopically appear to be formed in multilayered cellular arrangements around fibrovascular stalks. This gives the pseudopapillary appearance. There are key characteristic elements of SPTs, such as the presence of cholesterol clefts, pseudopapillary formation, foamy macrophages, globules of hyaline components, and the lack of the presence of neuroendocrine chromatin material [14], [15].

The prognosis of SPTs is usually greatly favorable for patients with a patient cure rate of >95 % after undergoing complete and utter surgical resection of the tumor [2], [5], [9]. On the other hand, vascular invasion caused by the tumor, invasiveness into adjacent anatomical structures, and vital organs cannot definitively predict the course of SPTs malignant behavior [5].

SPTs typically behave as benign tumors. Nonetheless, tumor recurrence may take place and < 15 % of cases may undergo metastasis. The most common metastatic sites are the liver and the peritoneum [2], [4], [16].

Regarding survival rates, the 10-year survival rate of patients affected by SPTs is >90 % [2], [17].

Even though SPTs were documented for the first time by Frantz in 1959 where it was depicted as a tumor class with both cystic and solid elements [18], to the best of our knowledge, no previous cases from our country of Solid Pseudopapillary Tumors of the Pancreas were documented in the published literature. Therefore, we believe this rare entity warrants further investigation and scientific documentation to allow further study and innovative diagnostic and therapeutic interventions to take place.

4. Conclusion

Pancreatic SPTs are extremely rare pancreatic malignancies that could result in high patient morbidity and mortality. After a careful review of the published literature, we found that no previously published cases of SPTs from our country exist. Documentation of such rare types of neoplasia is warranted to raise awareness and to establish and innovate the necessary clinical protocols to adequately diagnose, treat, and follow up on the affected patients. Further research is mandated to reach these goals.

Ethics approval and consent to participate

Institutional review board approval is not required for deidentified single case reports or histories based on institutional policies.

Consent of patient

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Availability of data and materials

The datasets generated during and/or analyzed during the current study are not publicly available because the Data were obtained from the hospital computer-based in-house system. Data are available from the corresponding author upon reasonable request.

Sources of funding

Not applicable.

Research registration

Not applicable.

Provenance and peer review

Not commissioned, externally peer-reviewed.

Guarantor

Omar Al Laham.

CRediT authorship contribution statement

OA: Conceptualization, resources, who wrote, original drafted, edited, visualized, validated, literature reviewed the manuscript, and the corresponding author who submitted the paper for publication.

RS: Manuscript writing and editing, validation, resources, literature review, and review of the manuscript.

ZI: Histopathology PhD student who analyzed the resected specimens, validated, and reviewed of the manuscript.

AM, HZ: Primary surgical assistants during the operation. Supervision, validation, resources, and review of the manuscript.

HH: General Surgery professor who performed and supervised the operation, in addition to supervision, project administration, resources, and review of the manuscript.

All authors read and approved the final manuscript.

Declaration of competing interest

Not applicable.