UNASSIGNED: Hepatic Inflammatory Pseudotumor (IPT) is an infrequent condition often masquerading as a malignant tumor, resulting in misdiagnosis and unnecessary surgical resection. The emerging concept of IgG4-related diseases (IgG4-RD) has gained widespread recognition, encompassing entities like IgG4-related hepatic IPT. Clinically and radiologically, corticosteroids and immunosuppressive therapies have proven effective in managing this condition.
UNASSIGNED: A 3-year-old Chinese boy presented to the clinic with an 11-month history of anemia, fever of unknown origin, and a tender hepatic mass. Blood examinations revealed chronic anemia (Hb: 6.4 g/L, MCV: 68.6 fl, MCH: 19.5 pg, reticulocytes: 1.7%) accompanied by an inflammatory reaction and an elevated serum IgG4 level (1542.2 mg/L). Abdominal contrast-enhanced computed tomography unveiled a 7.6 cm low-density mass in the right lateral lobe, while magnetic resonance imaging demonstrated slight hypointensity on T1-weighted images and slight hyperintensity on T2-weighted images, prompting suspicion of hepatic malignancy. A subsequent liver biopsy revealed a mass characterized by fibrous stroma and dense lymphoplasmacytic infiltration. Immunohistochemical analysis confirmed the presence of IgG4-positive plasma cells, leading to the diagnosis of IgG4-related hepatic IPT. Swift resolution occurred upon initiation of corticosteroid and mycophenolate mofetil therapies.
UNASSIGNED: This study underscores the diagnostic approach to hepatic IPT, utilizing histopathology, immunostaining, imaging, serology, organ involvement, and therapeutic response. Early histological examination plays a pivotal role in clinical guidance, averting misdiagnosis as a liver tumor and unnecessary surgical interventions.

BACKGROUND: Inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) of the liver is rare. It was previously believed that Epstein-Barr virus (EBV) positivity was a necessary criterion for pathological diagnosis. However, we found that there were also cases of EBV negativity. Therefore, clinicians and pathologists are reminded that EBV positivity is not a necessary condition for diagnosis.
METHODS: A 70-year-old female underwent computed tomography (CT) examination for upper abdominal discomfort, which revealed the presence of a liver tumor. Follow-up revealed that the tumor had progressively increased in size.
METHODS: The final diagnosis was an IPT-like follicular cell sarcoma, based on CT, MRI, HE staining, and immunohistochemical staining.
METHODS: The patient underwent a laparoscopic left hemihepatectomy.
RESULTS: The patient has not undergone any special treatment, such as radiotherapy and chemotherapy, and has been followed up for over 3 years without experiencing any recurrence.
CONCLUSIONS: IPT-like FDCS is a rare tumor that lacks definitive criteria, and its diagnosis mainly relies on pathological findings. Previously, it was believed that being EBV-positive was an important condition for diagnosis. Primary IPT-like FDCS in the liver is even rarer, and the patient in this case tested negative for EBV. It may be necessary for pathologists to consider the role of EBV in the diagnosis of IPT-like FDCS.

BACKGROUND: Epstein-Barr virus-positive inflammatory follicular dendritic cell sarcoma (EBV+IFDCS) is a rare disease characterized by mild clinical symptoms and non-specific imaging findings. The diagnosis of the disease depends on pathological diagnosis. However, EBV+IFDCS has a very broad spectrum of histological morphology and immune phenotypes, and its histopathological features have not been fully described by pathologists.
METHODS: A 59-year-old female, with no significant discomfort, was found to have a splenic mass during a routine physical examination. Microscopic examination at low magnification revealed numerous epithelioid granulomas, amidst which a substantial inflammatory response was observed. Interspersed among the dense inflammatory cells were spindle or oval-shaped cells, distributed sporadically with indistinct boundaries. Under high magnification, these spindle cells had subtle features: smooth and clear nuclear membranes, inconspicuous small nucleoli, and infrequent mitotic figures. Immunophenotypically, the spindle cells expressed CD21 and CD23, and Epstein-Barr encoding region (EBER) in situ hybridization yielded positive results. The inflammatory milieu predominantly consisted of T cells, with a minority of plasma cells expressing IgG4. The confluence of morphological and immunohistochemical findings led to the final pathological diagnosis of EBV+IFDCS in this case.
CONCLUSIONS: The presentation of EBV+IFDCS with pronounced granulomatous changes is rare. This morphological variant poses a high risk of misdiagnosis, frequently leading to confusion with other granulomatous diseases. Accurate diagnosis necessitates a comprehensive analysis, integrating immunohistochemistry and in situ hybridization. The case presented here is instrumental in raising awareness and understanding of EBV+IFDCS, with the goal of reducing misdiagnoses and unrecognized cases.

BACKGROUND: We present a case of an inflammatory myofibroblastic tumor cured with a short period of steroid administration, a treatment previously unreported for such cases.
METHODS: A 49-year-old man had a chief complaint of chest pain for more than 3 days. Computed tomography (CT) revealed a tumoral lesion suspected to have infiltrated into the right first rib and intercostal muscles, with changes in lung parenchymal density around the lesion. The maximal standardized uptake value on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography was high (16.73), consistent with tumor presence. CT-guided biopsy revealed an inflammatory myofibroblastic tumor with no distant metastases. Surgery was indicated based on the disease course. However, he had received an oral steroid before the preoperative contrast-enhanced CT scan due to a history of bronchial asthma, and subsequent CT showed that the tumor shrank in size after administration; he has been recurrence-free for more than a year.
CONCLUSIONS: Surgery is still the first choice for inflammatory myofibroblastic tumors, as the disease can metastasize and relapse; however, this condition can also be cured with a short period of steroid therapy.

A woman in her 70s was admitted to our institution with complaints of right hypochondrium pain. Abdominal computed tomography revealed a 13-mm retroperitoneal tumor between the liver and right kidney. The tumor rapidly increased to 82mm within 2 months, a necrotic change was inside the tumor, and the inflammation spread to the surrounding diaphragm and the peritoneum. The patient underwent surgical resection including the affected diaphragm and the peritoneum. Histopathological examination revealed a myofibroblastic spindle-cell proliferation with prominent infiltration of inflammatory cells, such as the plasma cells, lymphocytes, neutrophils, and eosinophils, diagnosed as an inflammatory myofibroblastic tumor (IMT) based on positive smooth muscle actin staining. IMT arising from the retroperitoneum is a rare case in Japan;we report this case with literature review.

Metastatic inflammatory myofibroblastic tumor (IMT) is very rare and detailed reports on diagnosis and treatment are limited. Here, we report a case of metastatic IMT with ALK rearrangement. A 73-year-old woman was diagnosed with IMT involving a brain metastasis. Next generation sequencing (NGS) panel testing with Oncomine dx target test revealed that her tumor was positive for EML4-ALK. Treatment with alectinib was initiated, resulting in remarkable shrinkage of both the primary tumor and the brain metastasis. This report is the first to identify ALK rearrangement in IMT using a commercially available NGS panel testing, followed by treatment with alectinib. This case suggests that NGS panel testing may be useful in the diagnosis and treatment of patients with metastatic IMT.

Inflammatory pseudotumour (IP) is a rare proliferative disease characterized by a dense infiltrate of plasma cells, lymphocytes, eosinophils and neutrophils in the fibrous stroma. It primarily affects the lungs of pediatric patients or young adults. Cutaneous IP is an extremely rare condition, with limited documentation in the English literature. In this case report, we presented an unusual instance of a 62-year-old male endured recalcitrant cutaneous IP for 8 years and exhibited poor response to topical glucocorticoid therapy, as well as intralesional injections of pingyangmycin and/or corticosteroid. Notably, after undergoing four sessions of 5-aminolevulinic acid photodynamic therapy (ALA-PDT), the patient experienced a significant reduction in erythema and nodules. This observation suggests that ALA-PDT may represent a promising and safe treatment option for cutaneous IP.

BACKGROUND: Inflammatory myofibroblastic tumor (IMT) is an uncommon benign myofibroblastic tumor that usually occurs in the lung, mediastinum, abdomen and vulvovaginal region. IMT of the upper arm is exceedingly rare with unknown etiology. Pathology plays a major role in the diagnosis of IMT, and radiological characteristics of the condition are crucial for differential diagnosis.
METHODS: A 62-year-old woman was admitted to our hospital for a complaint of a mass in her left upper limb with progressive numbness in the extremity. Ultrasound examination of the brachial artery (BA) revealed a hypoechoic mass with well-defined borders and a substantial blood flow, and the mass was also shown to be greatly enhanced on computed tomography (CT) and magnetic resonance imaging (MRI).
METHODS: The subsequent histopathological and immunohistochemical studies led to the diagnosis of IMT.
METHODS: The patient was referred for surgery. The soft tissue tumor resection, left median nerve release operation, brachial artery vascular grafting, and arterial anastomosis were performed.
RESULTS: Favorable outcome was observed. The patient recovered well from the procedure and did not experience any further complications or tumor recurrence.
CONCLUSIONS: In this report, we describe a case of IMT of the upper arm with BA involvement. The case expands the differential diagnosis of limb neoplasm and broadens the understanding of its ultrasonic and radiological imaging features. It also serves as a further example of an uncommon region distinct from conventional IMT. Further studies on the etiology and therapeutic strategies are needed.

Inflammatory myofibroblastic tumor （IMT） is a rare mesenchymal soft tissue tumor characterized by borderline or low-grade malignancy. It is rare childhood tumor with an average age of onset of 10 years old. It is even rarer in infants and toddlers, and the etiology and pathogenesis of this tumor are still unclear. The clinical presentation of IMT is non-specific and are related to the location of the tumor. When the tumor compresses adjacent organs, it can cause pain and functional impairment. According to the current literature, IMT is most commonly found in the digestive and respiratory systems, but also occasionally occur in the genitourinary system, head and neck, and limbs. At present, there have been no reports of nasopharyngeal IMT involving nasal cavity of infants and toddlers at home and abroad.This article reports a case of a massive inflammatory myofibroblastic tumor involving the nasal cavity and nasopharynx in an infant. Plasma-assisted minimally invasive surgery was performed through multiple surgical approaches and achieved satisfactory therapeutic results. This case report may provide valuable reference for the treatment of similar diseases.
摘要: 炎症性肌纤维母细胞瘤（inflammatory myofibroblastic tumor，IMT）是一种间叶性软组织肿瘤，生物学特性多表现为交界性或低度恶性。该肿瘤是一种罕见的儿童期肿瘤，平均发病年龄10岁，婴幼儿更为罕见，其病因与发病机制目前尚不清楚。临床表现无特异性，其临床表现与肿瘤发生部位有关，当肿瘤占位对相邻器官产生压迫，会表现为疼痛及功能障碍。从目前文献报道来看，发病部位以消化、呼吸系统居多，也偶见泌尿生殖系统、头颈部及四肢，其发生于婴幼儿鼻咽部累及鼻腔，笔者尚未见国内外相关报道。本文报道1例累及婴幼儿鼻腔和鼻咽的巨大IMT，通过多个手术路径行等离子微创手术获得满意疗效，可为此类疾病的治疗提供参考。.

Anisakiasis is a parasitic infection caused by the ingestion of raw or undercooked seafood infected with Anisakis larvae. It generally affects the gastrointestinal tract, particularly the stomach, but very rare cases have been reported in which infection of the liver leads to the formation of inflammatory pseudotumors. We herein report an extremely rare case of an inflammatory pseudotumor induced by hepatic anisakiasis that was laparoscopically resected for the purpose of both diagnosis and treatment. A 51-year-old woman underwent a routine medical checkup by ultrasound examination, which incidentally detected a 15-mm mass on the surface of S6 of the liver. Because a malignant tumor could not be ruled out on several preoperative imaging studies, laparoscopic partial resection of the liver was performed. Histopathological examination revealed Anisakis larva in the inflammatory pseudotumor, suggesting hepatic anisakiasis. This report describes an extremely rare case of an inflammatory pseudotumor induced by hepatic anisakiasis. Because the preoperative diagnosis could not be obtained by several imaging modalities, laparoscopic liver resection with a sufficient margin might be suitable for diagnosis and treatment of this disease.