title: Hyaline globules in neuroendocrine and solid-pseudopapillary neoplasms of the pancreas: a clue to the diagnosis.
abstract: Distinguishing between solid-pseudopapillary neoplasms (SPNs) and pancreatic neuroendocrine tumors (PanNETs) may pose a diagnostic dilemma. Both can demonstrate solid growth patterns, and both can be immunoreactive with neuroendocrine markers such as synaptophysin and CD56. One well-established feature of SPNs is the presence of hyaline globules, which in contrast has only rarely been reported in PanNETs. Clinicopathologic features of 361 cases originally classified as PanNETs were examined. Of these, 24 tumors (6.6%) had hyaline globules, raising the possibility of SPN. Immunohistochemistry for β-catenin was performed on these 24 neoplasms, and showed nuclear labeling in 6 cases. These 6 cases, which also demonstrated cytoplasmic CD10 staining, were reclassified as SPNs. The remaining 18 cases maintained their original diagnosis as PanNETs, and the hyaline globules in these cases were periodic acid-Schiff (PAS) positive, diastase resistant, and immunoreactive with α-1-antitrypsin. All 24 cases were histologically re-evaluated, and the pattern of invasion, presence of clear cells, and nuclear grooves were found to be helpful in distinguishing SPNs from PanNETs. We conclude that the presence of hyaline globules should raise SPNs in the differential diagnosis of a solid cellular neoplasm of the pancreas. However, this should not be used as the sole criterion in the diagnosis of SPNs, as hyaline globules may also be seen in 5% of PanNETs. Immunohistochemical and histologic features supporting the diagnosis of SPNs over PanNETs include CD10 and nuclear β-catenin labeling, an insidious pattern of invasion, clear cells, and nuclear grooves.
authors.affiliation: Departments of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Zina
authors.initials: Z
authors.lastname: Meriden
authors.forename: Chanjuan
authors.initials: C
authors.lastname: Shi
authors.forename: Barish H
authors.initials: BH
authors.lastname: Edil
authors.forename: Trevor
authors.initials: T
authors.lastname: Ellison
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Wolfgang
authors.forename: Toby C
authors.initials: TC
authors.lastname: Cornish
authors.forename: Richard D
authors.initials: RD
authors.lastname: Schulick
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Hruban
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D018278:Carcinoma, Neuroendocrine / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D002291:Carcinoma, Papillary / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D005260:Female; D006801:Humans; D006818:Hyalin / Q000378:metabolism*; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D010503:Periodic Acid-Schiff Reaction; D051176:beta Catenin / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C495270:CTNNB1 protein, human; D051176:beta Catenin; D015260:Neprilysin