# Splenic inflammatory pseudotumor-like follicular dendritic cell sarcoma: a case report with imaging features and literature review

## TL;DR

This case report describes a rare splenic tumor that resembles an inflammatory pseudotumor and highlights its imaging features to aid in diagnosis.

## Contribution

The study presents a new case of splenic IPT-like FDCS and identifies specific MRI features for early detection.

## Key findings

- The tumor showed progressive inhomogeneous enhancement on MRI.
- A peripheral hypointense ring on T2-weighted imaging was a notable feature.
- Histopathology confirmed the diagnosis of IPT-like FDCS after splenectomy.

## Abstract

Follicular dendritic cell sarcoma (FDCS) is an extremely rare malignant neoplasm originating from immune follicular dendritic cells. Its inflammatory pseudotumor-like subtype (IPT-like FDCS) is even more uncommon due to morphological overlap with inflammatory pseudotumors. We report a case of splenic IPT-like FDCS and perform a systematic literature review to clarify the multimodal imaging characteristics of this rare entity.

A 50-year-old asymptomatic man had an incidentally detected splenic mass during routine health screening. Ultrasound showed a well-defined hypoechoic splenic lesion. Magnetic resonance imaging revealed slightly hyperintense signals on both T1- and T2-weighted images, with progressive inhomogeneous enhancement and a peripheral hypointense ring on T2-weighted sequences. The patient underwent splenectomy, and IPT-like FDCS was confirmed via histopathology and immunohistochemistry.

Splenic IPT-like FDCS typically presents with nonspecific or subclinical manifestations, making noninvasive imaging modalities crucial for diagnostic hint. Progressive heterogeneous enhancement and a peripheral hypointense ring on T2-weighted imaging may be valuable imaging features for identifying this rare malignancy.