Inflammatory pseudotumor-like follicular dendritic cell tumor of the liver with expression of estrogen receptor suggests a pathogenic mechanism: a case report and review of the literature

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.

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

BACKGROUND

Follicular dendritic cell sarcoma is a rare stromal tumor with no standard treatment. However, some reports have revealed that follicular dendritic cell sarcoma has an inflammatory pseudotumor variant associated with Epstein-Barr virus infection that has a relatively good prognosis. In this report, we present a case of a resected inflammatory pseudotumor variant of follicular dendritic cell sarcoma of the liver, and have reviewed the literature on the clinicopathological, molecular, and genomic features of this tumor.

CASE PRESENTATION

The inflammatory pseudotumor variant of follicular dendritic cell sarcoma originates only in the liver or spleen, causes no symptoms, and is more common in middle-aged Asian women. It has no characteristic imaging features, which partially explains why the inflammatory pseudotumor variant of follicular dendritic cell sarcoma is difficult to diagnose. Pathologically, the inflammatory pseudotumor variant of follicular dendritic cell sarcoma has spindle cells mixed with inflammatory cells and is variably positive for follicular dendritic cell markers (CD21, CD23, and CD35) and Epstein-Barr virus-encoded RNA. On genetic analysis, patients with this tumor high levels of latent membrane protein 1 gene expression and extremely low levels of host C-X-C Chemokine Receptor type 7 gene expression, indicating that the inflammatory pseudotumor variant of follicular dendritic cell sarcoma has a latent Epstein-Barr virus type 2 infection.

CONCLUSIONS

The inflammatory pseudotumor variant of follicular dendritic cell sarcoma is an Epstein-Barr virus-associated tumor and a favorable prognosis by surgical resection, similar to Epstein-Barr virus-associated gastric cancer.

Hepatic inflammatory pseudotumor-like follicular dendritic cell tumor with hepatic lymphoma history: A case report and literature review

RATIONALE

Hepatic inflammatory pseudotumor (IPT)-like follicular dendritic cell (FDC) sarcoma is a very rare disease. Till now, only 19 cases were reported in the English literature. However, the coexistence of IPT-like sarcoma and non-Hodgkin lymphoma (NHL) in the same patient has never been reported. In this report, we presented a case of hepatic IPT-like FDC with hepatic NHL history of which both were successfully resected.

PATIENT CONCERNS

We reported a case of a 47-year-old male patient who presented with right upper abdominal discomfort. Nineteen years ago, he underwent liver resection of segment VII for hepatic NHL (B-cell lymphoma). He had a history of chronic hepatitis B virus infection. Serum alpha fetoprotein level was normal. However, imaging studies revealed a well-circumscribed, solid mass in the right hepatic lobe, he came back to the clinic because he was worried about a recurrence of the B-cell lymphoma.

DIAGNOSES

Based on the patient's past medical history and magnetic resonance imaging results, and he was diagnosed as hepatocellular carcinoma or hepatic NHL preoperatively.

INTERVENTIONS

Right hemi-hepatectomy was performed on this patient.

OUTCOMES

Histological report showed features of a mixture of chronic inflammatory cells and variable amounts of spindle cells. Also, immuno-histo-chemical studies demonstrated that all the tumor cells showed strong nuclear in situ labeling for EBV-encoded small RNAs and strongly positive stainings with CD21 and CD35. The patient tolerated the surgery well, recovered smoothly and he was discharged on postoperative day 7 (day 7). The patient is still disease free after a follow-up of over 50 months.

CONCLUSIONS

To our knowledge, this is the first report demonstrating hepatic IPT-like FDC sarcoma in a patient with primary hepatic NHL history. In regards to treatment, complete surgical resection should be performed and would acquire excellent long-term outcomes.

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.