Extrapancreatic solid pseudopapillary tumors: A clinicopathological analysis of two cases

Abstract

Solid pseudopapillary tumors (SPTs) are unusual neoplasms that mostly occur in the pancreas, and predominantly affect young women. As a low-grade malignant neoplasm of the exocrine pancreas, they occasionally metastasize, usually to the liver or peritoneum. It has been reported that <1% of SPTs are primary extrapancreatic SPTs. In the present study, we present two rare, but conspicuous extrapancreatic SPTs. Both occurred in young women, and showed good prognoses following surgery. One was a recurrent SPT of the pancreas that metastasized to the ovary, and the other was a distinct primary neoplasm that arose in the retroperitoneal area. The pathological features of the two tumors, including solid and pseudopapillary growth patterns with pale or eosinophilic cytoplasm, were characteristic of SPTs of the pancreas. However, in the case of the metastatic ovarian tumor, focal necrosis and an increased nuclear-to-cytoplasmic ratio were observed. The presence of positive nuclear-cytoplasmic β-catenin, the loss of membranous E-cadherin expression, and a perinuclear punctate CD99 staining pattern on immunohistochemistical analysis, were essential features for diagnosis. The aim of the present study was to compare the morphological and immunohistochemical features of these tumors with those typical of pancreatic SPTs, and to raise awareness that SPTs are able to metastasize to unusual sites, and may also arise as primary tumors outside the pancreas, which may lead to diagnostic dilemmas. Case reports Clinical features Case 1. A 22-year-old woman presented at the Emergency Department of our hospital with sudden abdominal pain; two years previously, the patient had been diagnosed with a pancreatic SPT that had extensively metastasized into the abdominal cavity. A review of her medical history revealed that the patient

Ovarian Solid Pseudopapillary Tumor Resembling Benign Hemorrhagic Cyst on Rapid Frozen Section

“…Solid pseudopapillary tumors usually arise in the pancreas as a low-grade, indolent neoplasm. In rare cases, pancreatic SPTs may be aggressive and metastasize to the liver or peritoneum, or even more rarely to the ovary [9]. Less than 1% of SPTs are primary extrapancreatic tumors [9], with only 10 cases of primary ovarian SPTs reported to date in the English literature [1][2][3][4][5][6][7][8].…”

“…In terms of tumor site, there does not appear to be a predominance of the left ovary versus the right ovary. As with primary pancreatic SPTs, the majority of primary ovarian SPTs have an indolent course, and prognosis is usually very favorable after surgical resection [9]. However, in one exceptional case, metastases of the primary ovarian SPT were noted to the omentum, parametrium, and pelvic lymph nodes; after surgical management (i.e., right salpingo-oophorectomy, total omentectomy, pelvic lymph node dissection, and tumor debulking), the patient remained disease-free on a CT scan 18 months after surgery.…”

Extrapancreatic primary solid pseudopapillary tumor in the gastric antrum: Case report

“…Extrapancreatic locations of SPT (EPSPT) are extremely rare, with about 30 cases in the literature (Table S1) 3,8‐34 . Their preoperative diagnosis is extremely difficult because of nonspecific symptoms.…”

Solid pseudopapillary neoplasm: Report of a case of primary ovarian origin and review of the literature

“…Additionally, SPNs were identified at extrapancreatic localizations in approximately 1.1% of cases with SPN-Ps [ 3 ]. To our knowledge, there have been 27 cases of primary extrapancreatic SPNs reported in the literature [ [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] ]. The predominant extrapancreatic locations for SPNs included the ovary, mesentery and mesocolon, omentum, stomach, and retroperitoneum [ [3] , [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] ].…”