Comparison of the clinicopathological features of pancreatic solid pseudopapillary neoplasms between males and females: gender does matter

Yi Zou¹, Yan Huang¹, Bo Hong¹, Xueping Xiang¹, Bin Zhou² and Shumei Wei<sup>1,3,4

1</sup>Department of Pathology, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, ²Department of Pathology, Yuyao People's Hospital of Zhejiang Province, Yuyao, ³Zhejiang Provincial Key Laboratory of Pancreatic Disease, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou and ⁴Zhejiang Provincial Innovation Center for the Study of Pancreatic Disease, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China

Offprint requests to: Shumei Wei, Department of Pathology, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, 310000, Zhejiang Province, China. e-mail: 2307001@zju.edu.cn

Summary. Background. Solid pseudopapillary neoplasms (SPN) of the pancreas are a rare and low-grade malignant entity with a female predominance. However, it also occurs in males, but the rarity and lack of concern makes its clinicopathological features unclarified. Methods. The morphological, immunohisto-chemical, prognostic features and CTNNB1 exon 3 mutation status of SPN were compared semi-quantitively between 9 male and 21 female patients. Results. SPN in males grew in a distinctive solid pattern, with abundant fibrotic stroma and clear cells. Collagen tended to be the main component of tumor stroma in males, while hyaluronan composed a considerable proportion in females. A much stronger expression of androgen receptor (AR) was found in males, and CD56 and/or synaptophysin (Syn) was expressed frequently in both genders. All patients survived. One male patient had post-operational liver nodules and accepted interventional therapy without biopsy. Mutations of CTNNB1 exon 3 were observed in all cases, distributed at codon 32, 33 and 37 in both genders, as well as 34, 41 and 62 in females. Conclusion. SPN in males presented with significantly different morphological features from that in females, which might be helpful in differential diagnosis, especially when with extensive positivity for CD56 and/or Syn. The stronger expression of AR in males might be a clue to explore the underlying mechanism of the gender difference. Histol Histopathol 35, 257-268 (2020)

Key words: Solid pseudopapillary neoplasms, Clinicopathology, Androgen receptor, CTNNB1

DOI: 10.14670/HH-18-156