Solitary fibrous tumor of the pancreas clinically mimicking a pancreatic neuroendocrine tumor: Cytologic pitfalls when a transgastric approach is utilized

Abstract

Solitary fibrous tumor (SFT) involving the pancreas is a rare entity often diagnosed on surgical specimens rather than cytology samples. Pancreatic SFT frequently mimics pancreatic neuroendocrine tumor radiographically, which presents unique challenges to the cytologist during rapid on-site assessment. We describe a case of pancreatic SFT with a focus on the cytologic pitfalls that might be encountered during transgastric procedures. We also review the available cytologic findings of prior pancreatic SFT cases.

Tumor fibroso solitario de páncreas: reporte de caso

“…Realizar el diagnostico de este tipo de tumores re presenta un desafío debido a la localización anató mica, lo cual representa una limitante al momento de tomar biopsia. Las diferentes publicaciones muestran biopsia por aguja fina transgástricas, con certezas diagnósticas de 9% [7,10]. Esto debido a fragmentos celulares de otro epitelio (mucosa gás trica) y un solapamiento con otras entidades como tumor del estroma gastrointestinal (GIST), schwan noma y las neoplasias del músculo liso.…”

“…Esto debido a fragmentos celulares de otro epitelio (mucosa gás trica) y un solapamiento con otras entidades como tumor del estroma gastrointestinal (GIST), schwan noma y las neoplasias del músculo liso. Dada la su perposición citológica entre estas entidades, las tinciones de inmunohistoquímica (IHQ) son indis pensables para llegar a un diagnóstico correcto [7,8,9]. La inmunohistoquímica muestra positividad para CD34, vimentina, CD99 y STAT 6.…”

Cytomorphological spectrum of solitary fibrous tumour: revisited

“…These tumours were first reported in pleura but are also detected at extra‐pleural locations 2,3 . The underlying genetic pathology is a paracentric inversion in chromosome 12q, leading to NAB2‐STAT6 gene fusion, which further activates several growth factor pathways 1,2,4 . Morphologically, these tumours are composed of spindle‐shaped cells along with prominent, dilated and branching blood vessels, described as “staghorn vasculature” 5 .…”