Objective: To investigate the clinicopathologic and molecular genetic characteristics, diagnosis, differential diagnosis, treatment and prognosis of histiocyte-rich rhabdomyoblastic tumor (HRRMT). Methods: The clinical data of two cases of HRRMT diagnosed in Fujian Provincial Hospital and Fujian University of Traditional Chinese Medicine Affiliated People's Hospital from 2020 to 2021 were collected. Histopathology and immunohistochemical (IHC) staining were used to assess morphological changes; the genetic changes were analyzed with next-generation sequencing. The relevant literature was reviewed. Results: Both cases showed well-defined solid nodules and soft masses. Microscopically, the tumors had a fibrous pseudocapsule with lymphocytic aggregation, and locally invaded the surrounding skeletal muscle tissue, and the tumor cells were fusiform to epithelioid with an intensive foamy histiocytic infiltrate. No necrosis or mitosis was observed. Immunophenotyping showed the tumor cells were positive for desmin, either one or both skeletal muscle markers (myogenin or MyoD1), and negative for h-caldesmon, ALK and SMA. The Ki-67 index was<5%. Using next-generation sequencing, one case was found to harbour KRAS (G12D) and MSH3 (Q470^*) mutations. Conclusions: HRRMT is a newly described skeletal muscle tumor with uncertain malignant potential. Its diagnosis and differential diagnosis depend on morphologic and IHC staining. No specific molecular genetics changes have been identified so far.
Biomarkers, Tumor/analysis* ; Diagnosis, Differential ; Histiocytes/pathology* ; Humans ; Molecular Biology ; Muscle Neoplasms/pathology* ; Prognosis

Histiocytes/pathology* ; Humans ; Lymphoma, Extranodal NK-T-Cell/pathology* ; Nose Neoplasms/surgery*

histiocytes on histology, leading to the diagnosis of gastric xanthoma.]]>
Abdominal Pain ; Adult ; Appetite ; Child ; Deglutition Disorders ; Diagnosis ; Endoscopy ; Gastritis ; Helicobacter pylori ; Histiocytes ; Humans ; Incidental Findings ; Male ; Nausea ; Pediatrics ; Stomach Neoplasms ; Vomiting ; Xanthomatosis

Pigmented villonodular synovitis is a benign tumor arising from synovial fibroblasts or histiocytes. There are diffuse and localized forms: the former involves the entire synovium and the latter consists of nodules, small tumefactions, or pedunculated masses. The knee is the joint most commonly affected and the clinical diagnosis is difficult, so initial misdiagnosis is common. We report a case of pigmented villonodular synovitis developing in the knee of rheumatoid arthritis (RA) patient, mistaken for an RA flare-up.
Arthritis, Rheumatoid ; Diagnosis ; Diagnostic Errors ; Fibroblasts ; Histiocytes ; Humans ; Joints ; Knee ; Synovial Membrane ; Synovitis, Pigmented Villonodular

BACKGROUND: Juvenile xanthogranuloma is a benign, self-limited disorder that usually occurs in infants and young children. Xanthogranuloma is rare in adults, and therefore studies reporting adult xanthogranuloma are limited. OBJECTIVE: We investigated the clinical, histopathological, and immunohistochemical characteristics of adult xanthogranuloma. METHODS: In this study, we evaluated 20 lesions in 19 patients with adult xanthogranuloma. RESULTS: A male predominance was observed (male : female ratio 1.4 : 1), and the mean age of patients was 35.1±16.3 years (range 15∼66 years), with the peak incidence observed in patients in their 20s. Notably, 65.0% of the lesions developed on the head and neck. The nodular form was more common than the papular form of this condition. Histopathological examination revealed dense monomorphic histiocytic infiltration without lipidization and scattered eosinophils without multinuclear giant cells in 5 lesions (25.0%), foamy histiocytic infiltration with variations of completely developed Touton giant cells in 10 lesions (50.0%), and fibrohistiocytic proliferation in 3 lesions (15.0%). On immunohistochemical examination, histiocytes including giant cells showed positive test results with Factor XIIIa (90.9%), vimentin (100%), and CD68 (100%) and negative test results with CD1a, smooth muscle actin, and S-100 protein stains. Tumor excision was the treatment for choice. CONCLUSION: Adult xanthogranuloma most commonly manifested as the nodular form of the disease on the head and neck of men in their late 20s. Histopathologically, the classic Touton cell-rich stage was most commonly observed, followed by the stage of early predominantly mononuclear infiltration. This was a single-center, small-sized retrospective study; however, we expect the results of this study to contribute to a better understanding of adult xanthogranuloma.
Actins ; Adult ; Child ; Coloring Agents ; Eosinophils ; Factor XIIIa ; Female ; Giant Cells ; Head ; Histiocytes ; Humans ; Incidence ; Infant ; Male ; Muscle, Smooth ; Neck ; Retrospective Studies ; S100 Proteins ; Vimentin ; Xanthogranuloma, Juvenile

Rosai-Dorfman disease, also known as the sinus histiocytosis with massive lymphadenopathy, is a rare and benign histioproliferative disease in which lymphadenopathy results from infiltration and dilatation of lymph node sinuses by large histiocytes. We experienced a case of a 59-year-old man, presenting bilateral cervical masses with pain since one month ago. Radiologically, there were multiple enlarged lymph nodes with homogenous contrast enhancement at both cervical areas. Excisional biopsy revealed that the tumor was consistent with the Rosai-Dorfman disease. The patient was treated successfully with corticosteroid. Herein, we report our experiences with literature reviews.
Biopsy ; Dilatation ; Histiocytes ; Histiocytosis ; Histiocytosis, Sinus ; Humans ; Lymph Nodes ; Lymphatic Diseases ; Middle Aged ; Neck

Histiocytic sarcoma is a rare hematologic malignancy, with very few cases of primary histiocytic sarcoma of the breast described in English scientific literature. Herein, we describe a case of primary histiocytic sarcoma of the breast in a 75-year-old woman, with no clinical history of malignant tumors, who presented with a palpable solitary breast mass. Microscopically, the resected breast mass showed large pleomorphic cells, some multinucleated giant cells, and admixed inflammatory components. The pleomorphic tumor cells further showed a diffuse, noncohesive growth pattern, an abundant eosinophilic cytoplasm, and strong and diffuse immunoreactivity for cluster of differentiation (CD) 68 and CD163. Furthermore, a whole-body positron-emission tomography/computed tomography using deoxy-2-[¹⁸F]fluoro-D-glucose performed after surgery showed no other masses or lesions. After surgical excision, the patient was followed up, and no evidence of tumor recurrence or metastasis was noted.
Aged ; Breast ; Cytoplasm ; Eosinophils ; Female ; Giant Cells ; Hematologic Neoplasms ; Histiocytes ; Histiocytic Sarcoma ; Humans ; Neoplasm Metastasis ; Recurrence

A 33-year-old male had a 22-year history of generalized xanthogranulomas but had a normal lipid profile. He also developed ulcerating plaques on his arm and back that were consistent with cutaneous tuberculosis on histopathologic and polymerase chain reaction PCR studies. In a normolipemic patient with generalized xanthogranulomas, a reactive granulomatous response of histiocytes to infection is explored since these share a common CD 14+ precursor with the macrophages that are vital in tuberculosis.

PURPOSE: To report a case of immunoglobulin G4 (IgG4)-related ophthalmic disease associated with adult xanthogranulomatous disease. CASE SUMMARY: A 38-year-old male with a history of cholecystectomy visited our clinic for bilateral periorbital swelling. Histopathology of the orbital biopsy showed diffuse infiltration of foamy histiocytes with Touton giant cells and lymphoid follicles, with a diagnosis of adult-onset xanthogranuloma. After excisional biopsy, he was treated with azathioprine and prednisolone. Four years after treatment, he again visited the clinic due to bilateral, yellowish eyelid masses. Serological examinations were all nonspecific findings, except for elevation of IgG and IgG4 levels. Magnetic resonance imaging showed bilateral symmetric soft tissue enlargement with slightly heterogeneous T1/T2 isosignal intensity, with contrast enhancement at the superolateral aspect of extraconal spaces. Excisional biopsy and blepharoplasty were performed. Immunohistochemical sections showed that the IgG4+/IgG plasma cell ratio was 10–20% and the IgG4 plasma cell count was 22/high power field (HPF). His past sections of 2013 from the pathology department were again stained and showed that the IgG4+/IgG plasma cell ratio was 40–50% and the IgG4 plasma cell count was 59/HPF. Thus, he was definitely diagnosed with IgG4-related ophthalmic disease. CONCLUSIONS: If there is recurrent eyelid swelling, IgG4-related ophthalmic disease should be considered as a differential diagnosis. And the patient with adult xanthogranulomatous disease can be diagnosed with IgG4-related ophthalmic disease.
Adult ; Azathioprine ; Biopsy ; Blepharoplasty ; Cholecystectomy ; Diagnosis ; Diagnosis, Differential ; Eyelids ; Giant Cells ; Histiocytes ; Humans ; Immunoglobulin G ; Immunoglobulins ; Magnetic Resonance Imaging ; Male ; Orbit ; Pathology ; Plasma Cells ; Prednisolone

PURPOSE: A case of frosted branch angiitis in Kikuchi-Fujimoto disease is reported. CASE SUMMARY: A 33-year-old male complained of a sudden decrease in visual acuity that developed in both eyes 5 days prior. He suffered from a headache, chills, myalgia, and flank pain 1 week before. The initial best-corrected visual acuity (BCVA) was 0.1 in the right eye and 0.2 in the left eye. On slit lamp examination, no inflammatory finding was observed in the anterior chamber and vitreous body of both eyes. On fundus examination, a diffuse vascular sheathing-like frosted branch was found in the retinal vessels, and retinal hemorrhage was observed. Fluorescein angiography showed staining and leakage of dye along the vascular sheathing. Serological findings were negative, showing no evidence of an autoimmune disease or viral infection. Neck ultrasonography revealed non-tender left cervical lymph node enlargement >1 cm in diameter. Ultrasound-guided fine needle aspiration cytology showed findings compatible with Kikuchi-Fujimoto disease, including necrotic changes and pronounced karyorrhexis, plus histiocyte and lymphocyte infiltration without neutrophils. We started systemic steroid therapy. One month after treatment, the BCVA of both eyes improved to 1.0. CONCLUSIONS: In patients with frosted branch angiitis, systemic disease such as Kikuchi-Fujimoto disease should be considered.
Adult ; Anterior Chamber ; Autoimmune Diseases ; Biopsy, Fine-Needle ; Chills ; Flank Pain ; Fluorescein Angiography ; Headache ; Histiocytes ; Histiocytic Necrotizing Lymphadenitis ; Humans ; Lymph Nodes ; Lymphocytes ; Male ; Myalgia ; Neck ; Neutrophils ; Retinal Hemorrhage ; Retinal Vessels ; Slit Lamp ; Ultrasonography ; Vasculitis ; Visual Acuity ; Vitreous Body