Objective To investigate the MRI features of hepatic IgG4?related inflammatory pseudotumor (IPT). Methods Nine patients with 11 histopathologically proven IgG4?related hepatic IPTs were retrospectively analyzed. The clinical, morphological and MRI signal features on T1WI, T2WI, dynamic?enhanced, and diffusion?weighted imaging were assessed in detail and correlated with pathological findings. The paired t test was used to compare the ADC values of the tumors and the hepatic tissue. Results Hepatic IgG4?related IPT displayed certain MRI features. The dominant lesions were subcapsularly distributed (n=7) with a clear boundary (n=8), which typically showed hypointensity on T1WI (n=11), mild hyperintensity on T2WI (n=8), progressive (n=5) or persistent (n=4) enhancement pattern. Accompanied signs included delayed capsule?like enhancement (n=6) and central nonenhanced areas (n=7). Two lesions showed atypical wash?out pattern with iso or hypointensity on portal and delayed phases. In diffusion weighted imaging, all lesions were hyperintense, and the mean ADC value of the lesions [(1.42 ± 0.36) × 10?3mm2/s] was mildly lower than that of surrounding liver [(1.55±0.31)×10?3mm2/s], although no statistical differences were found(t=0.78, P=0.46). Conclusions Hepatic IgG4?related IPTs display various MRI manifestations. The lesions normally show progressive enhancement pattern with diffuse homogeneous or heterogeneous hyperintensity, accompanied by delayed capsule?like enhancement and central nonenhanced areas.

Objective: To study the clinicopathological features, diagnostic features and differential diagnoses of SMARCB1 (INI1)-deficient sinonasal carcinoma (SDSC). Methods: Six cases of SDSC diagnosed at Eye, Ear, Nose and Throat Hospital, Fudan University from 2016 to 2018 were retrieved; the clinical features, histomorphology, immunophenotype, radiology and outcome were analyzed with review of literature. Results: There were five men and one woman with age range of 37 years to 75 years (mean 56 years). One case was in stage T2, and 5 cases were in stage T4. Computer tomography and magnetic resonance imaging showed a mass occupying the sinonasal cavity with bone destruction in all six patients. Microscopically, the tumors had infiltrative margins. Four tumors were composed mostly of basaloid cells, which possessed high nuclear/cytoplasmic ratio,scant cytoplasm,and minimalnuclear pleomorphism; and the cells were arranged in sheets or nests in a desmoplastic stroma. Two tumors were composed of rhabdoid cells, which possessed abundant, eosinophilic cytoplasm and eccentric nuclei, often growing in a nests or sheets pattern. Immunohistochemical staining showed that 6/6 cases had complete loss of INI1, diffusely and strongly positive for CKpan, and were negative for S-100 and EBER ISH; 4/6 cases were focally positive for p63; 1/5 was focally positive for Syn and p16. The Ki-67 index was 30% to 70%. The follow-up period ranged 1-26 months, with one patient died of extensive metastases, one had local recurrence, and two had lymph node metastases; one was alive without disease, and one was lost to follow-up. Conclusions SMARCB1 (INI1)-deficient sinonasal carcinoma is mostly aggressive, with rapid progression and poor prognosis. Histomorphological spectrum predominantly consists of basaloid type and rhabdoid type. The complete loss of nuclear expression of INI1 can help to distinguish this tumor from its many mimickers.