Imaging findings of inflammatory pseudotumor-like follicular dendritic cell tumors of the liver: Two case reports and literature review

Case report: Hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma: a rare case and review of the literature

Inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) is a rare subtype of follicular dendritic cell sarcoma (FDCS) that primarily occurs in the liver and spleen. The etiology of IPT-like FDCS is unknown, and it has nonspecific clinical manifestations, imaging performance and laboratory test results. Recently, a patient with IPT-like FDCS was admitted to our hospital because of abdominal distension and anemia. Over the past 3 years, the patient has been followed up after a liver mass was found in a physical examination. The lesion gradually enlarged and caused compression symptoms. In November 2022, a tumor with a diameter of approximately 20 cm was found in the right posterior lobe of the liver after abdominal enhanced Magnetic resonance imaging (MRI) in our hospital. Liver tumor biopsy before the operation revealed a large number of hyperplastic plasma cells and a small number of spindle cells, and the spindle cells were atypical. After a complete examination, the patient underwent liver resection. Pathology after surgery confirmed liver IPT-like FDCS.

Case report: Hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma: A rare case and minireview of the literature

Inflammatory pseudotumor (IPT)-like follicular dendritic cell sarcoma (FDCS) is a rare neoplasm referred to as the FDCS variant. Here we report a 66-year-old female patient suffering from hepatic IPT-like FDCS and summarize IPT-like FDCS reported in the literature. The patient presented with obvious abdominal pain without significant laboratory abnormalities and subsequently underwent surgical resection of a hepatic lesion. Postoperative pathological results demonstrated a vascular tissue-rich neoplasm (7.0-cm maximum diameter). The tumor cells expressed CD21 and CD35, and in situ hybridization detected Epstein–Barr virus-encoded RNA (EBER). Metastasis or recurrence was not detected during the 7-year follow-up.

Hepatic Follicular Dendritic Cell Sarcoma with Epithelioid Morphology: Histopathologist's Perspective

Follicular dendritic cell (FDC) sarcoma is an uncommon tumor of the liver with only 30 previous cases reported in the English literature. Histopathological examination is the gold standard for the diagnosis of FDC sarcoma although the diagnosis is often missed because of its rarity. It usually presents with spindle-cell morphology although epithelioid/biphasic morphology is also well-known. This morphological variation can also pose a diagnostic challenge. We discuss a case of unresectable hepatic FDC sarcoma in an adult male who was diagnosed in core biopsy. We highlight the relevant histomorphological differentials and diagnostic approaches to FDC sarcoma in this anecdote.

Hepatic inflammatory pseudotumor-like follicular dendritic cell tumor: a case report

Background

Inflammatory pseudotumor-like follicular dendritic cell sarcoma is a rare histological variant of follicular dendritic cell sarcoma involving typically the spleen and the liver, often linked to the presence of Epstein–Barr virus infection. Definite diagnosis of this type of sarcoma is difficult to make owing to nonspecific clinical and imaging findings and is based on histopathological features. Inflammatory pseudotumor-like follicular dendritic cell sarcoma is described as a low-aggressivity tumor with a favorable prognosis.

Case presentation

We report the case of a 34-year-old Caucasian woman, Epstein–Barr virus positive, diagnosed with hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma and surgically treated in November 2014, who developed 6 years later a recurrence for which she underwent once again surgical treatment. As far as we know, fewer than 30 reports of inflammatory pseudotumor-like follicular dendritic cell liver tumors have been reported in the English literature.

Conclusions

Although it is an uncommon tumor, inflammatory pseudotumor-like sarcoma is a diagnostic worth being taken in consideration, and surveillance is recommended owing to the possibility of recurrence.

Epstein-Barr virus-negative inflammatory pseudotumor-like variant of follicular dendritic cell sarcoma of the liver: A case report and literature review

Follicular dendritic cell sarcoma (FDCS) can be divided into the conventional type, and the inflammatory pseudotumor (IPT)-like variant type. Epstein-Barr virus (EBV) infection is considered to be closely associated with the pathogenesis of IPT-like variant of FDCS. Hepatic FDCS has an exceedingly low incidence of only 29 cases reported, with most of these tumors being classified as the IPT-like type. We report a case of an IPT-like variant of FDCS of the liver in a 61-year old man who presented with no marked symptoms. The patient underwent laparoscopic surgery for the mass and was well during a 13-month follow-up periods. The postoperative pathological examination found a proliferation of spindle cells and a diffuse infiltration of inflammatory cells within the tumor. Immunohistochemistry revealed that neoplastic cells were positive for CD23, clusterin, fascin, and PD-L1, and weakly positive for CD35, SMA, and D2-40. The infiltrating lymphocytes were strongly positive for PD1, and IgG4-positive plasma cells were less than 10 cells/high-power field. In situ hybridization for Epstein-Barr virus encoded RNA (EBER) was negative. To our knowledge, the present case is the second case of hepatic IPT-like variant of FDCS without EBV involvement, indicating that EBV infection is not an absolute prerequisite for a diagnosis of the IPT-like variant of FDCS.