Inflammatory pseudotumors of the liver: Importance of a multimodal approach with the insistance of needle biopsy

Inflammatory Pseudotumor of the Liver or Intrahepatic Cholangiocarcinoma, That's the Question: A Review of the Literature

An inflammatory pseudotumor of the liver is a rare tumor-like lesion composed of polymorphous inflammatory cell infiltrates and variable amounts of fibrosis that can often mimic a malignant liver neoplasm. The etiology of inflammatory pseudotumors of the liver is unknown; symptoms are faint and imaging non-specific. Thus, it is often hard to make a diagnosis preoperatively and it is not so rare to over-treat patients with this disease or vice versa. Thus, more profound knowledge is necessary to plan appropriate disease management. We reported our two cases and systematically searched the literature regarding IPTL. We selected articles published in English from four databases, PubMed, Scopus, Web of Science and Google Scholar, and we included only articles with consistent data. Twenty nine papers fulfilling criteria for the review were selected. The analysis of 69 cases published from 1953 confirmed that the risk factors are unclear, the imaging data is not specific, and biopsy is crucial but not so widely used in clinical practice due to the procedure's related risks, and relatively low effectiveness and improvement in imaging analysis. Regarding treatment, surgeons have moved towards a more conservative attitude over the years due to better imaging quality and patient surveillance. However, surgery remains the modality of choice for most cases with an indeterminate diagnosis. Even if an inflammatory pseudotumor of the liver is a benign tumor with a good prognosis, not requiring any treatment in most cases, sometimes it remains challenging to differentiate it from ICC; therefore, there is a solid recommendation to manage this condition with a multidisciplinary team.

Fibrohistiocytic Variant of Hepatic Pseudotumor: An Antibiotic Responsive Tumefactive Lesion

Inflammatory pseudotumor is a term used to designate inflammation-rich tumefactive lesions. Following the exclusion of specific entities such as IgG4-related disease and other neoplastic entities previously included in this entity, the majority of hepatic pseudotumors show a prominent fibrohistiocytic inflammatory reaction and have been previously categorized as fibrohistiocytic variant of hepatic pseudotumor (FHVHPT). The goal of this study was to examine the clinical, radiologic, histologic, and etiologic aspects of this entity. After excluding neoplastic diseases, we identified 30 patients with FHVHPT from 3 institutions between 2009 and 2019. We extracted demographic and clinical data, liver function tests as well as culture results and radiologic information. Hematoxylin and eosin-stained slides were reviewed for pattern of inflammation as well as its cellular composition. Immunohistochemistry for IgG4 and IgG was performed in all cases. The mean age of the 30 lesions characterized as FHVHPT was 56 years (range: 23 to 79 y). Nineteen patients showed solitary lesions; 11 were multiple. The mean size of the lesion was 3.8 cm (range: 1 to 7.5 cm). On imaging, a neoplastic process or metastasis was the leading diagnostic consideration (n=15, 50%). The most common symptom was abdominal pain (n=14/30); 8 patients presented with symptoms compatible with an infectious process, including fever. The inflammatory infiltrate was dominated by lymphocytes and plasma cells, and in most cases, a prominent histiocytic infiltrate (22/30). Neutrophils were identified in 12 cases, with microabscess noted in 8. Storiform pattern of fibrosis was seen in 14/30 cases; obliterative phlebitis was not identified. Culture identified a microorganism in 4 of 9 cases evaluated. The mean IgG4 count was 9.3 per HPF (range: 0 to 51) with 9 of the 26 (35%) biopsies showing >10 IgG4 positive plasma cells per HPF. The mean IgG4 to IgG ratio was 8% (range: 8% to 46%). A hepatectomy was performed in 4 cases. On broad spectrum antibiotics (n=14) the lesions either resolved or decreased in size. Eight patients did not receive specific therapy, nevertheless, the lesion(s) resolved spontaneously in 6 cases, remained stable or decreased in size in 2 cases. Notably, none of these patients showed evidence of a hepatic recurrence. FHVHPT, a tumefactive lesion that mimics hepatic neoplasia, is histologically characterized by a fibrohistiocytic infiltrate. In the majority of patients FHVHPT represents the organizing phase of hepatic abscess and can be successfully managed with antibiotic therapy.