Histiocyte-rich rhabdomyoblastic tumor: a clinicopathological and molecular genetic analysis / 中华病理学杂志

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.

Gastric Xanthoma in the Pediatric Population: A Possible Herald for Malignancy? / 대한소아소화기영양학회지

Adult Xanthogranuloma: A Clinical, Histopathological, and Immunohistochemical Study of 19 Korean Cases / 대한피부과학회지

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.

Primary Histiocytic Sarcoma Presenting as a Breast Mass: A Case Report / 한국유방암학회지

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.

Pigmented Villonodular Synovitis Developing in the Knee of a Rheumatoid Arthritis Patient Mistaken as a Rheumatoid Arthritis Flare-Up / 대한내과학회지

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.

A Case of Rosai-Dorfman Disease Presented with Neck Mass / 대한이비인후과학회지

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.

Scanning electron microscopy of granuloma annulare

Abstract: Light microscopy of granuloma annulare shows mucin deposition with lympho-histiocytic infiltrate. We describe the ultrastructural three-dimensional aspects of a typical case of granuloma with characteristic histopathological findings. At the ultrastructural level, affected collagen bundles and granular mucin deposition were observed. Round cells corresponding to lymphocytes were identified. Bigger oval cells, corresponding to isolated or palisading histiocytes were also found. The ultrastructural aspects overlap with light microscopy and contribute to its iconographic documentation.

Occurrence of mesothelial/monocytic incidental cardiac excrescences in material from open-heart procedures: case reports and literature review

Mesothelial/monocytic incidental cardiac excrescences (MICE) are unusual findings during the histological analysis of material from the pericardium, mediastinum, or other tissues collected in open-heart surgery. Despite their somewhat worrisome histological appearance, they show a benign clinical course, and further treatment is virtually never necessary. Hence, the importance of recognizing the entity relays in its differential diagnosis, as an unaware medical pathologist may misinterpret it for a malignant neoplasm. Other mesothelial and histiocytic proliferative lesions, sharing very close histological morphology and immunohistochemistry features with MICE, have been described in sites other than the heart or the mediastinum. This similarity has led to the proposal of the common denomination "histiocytosis with raisinoid nuclei." We report three cases from the pathology archives of the Heart Institute of São Paulo University (Incor/HC-FMUSP), diagnosed as "mesothelial/monocytic incidental cardiac excrescence," with immunohistochemical documentation, and provide a literature review of this entity.

A case of cutaneous tuberculosis presenting with generalized xanthogranulomas

@#<p>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.</p>

Preoperative Cytologic Diagnosis of Warthin-like Variant of Papillary Thyroid Carcinoma

BACKGROUND: Warthin-like variant of papillary thyroid carcinoma (WLV-PTC) is a relatively rare variant of papillary thyroid carcinoma with favorable prognosis. However, preoperative diagnosis using fine-needle aspiration (FNA) specimens is challenging especially with lymphocytic thyroiditis characterized by Hürthle cells and lymphocytic background. To determine a helpful cytological differential point, we compared WLV-PTC FNA findings with conventional papillary thyroid carcinoma with lymphocytic thyroiditis (PTC-LT) and conventional papillary thyroid carcinoma without lymphocytic thyroiditis (PTC) regarding infiltrating inflammatory cells and their distribution. Preoperative diagnosis or potential for WLV-PTC will be helpful for surgeons to decide the scope of operation. METHODS: Of the 8,179 patients treated for papillary thyroid carcinoma between January 2007 and December 2012, 16 patients (0.2%) were pathologically confirmed as WLV-PTC and four cases were available for cytologic review. For comparison, we randomly selected six PTC-LT cases and five PTC cases during the same period. The number of intratumoral and background lymphocytes, histiocytes, neutrophils, and the presence of giant cells were evaluated and compared using conventional smear and ThinPrep preparations. RESULTS: WLV-PTC showed extensive lymphocytic smear with incorporation of thyroid follicular tumor cell clusters and frequent histiocytes. WLV-PTC was associated with higher intratumoral and background lymphocytes and histiocytes compared with PTC-LT or PTC. The difference was more distinct in liquid-based cytology. CONCLUSIONS: The lymphocytic smear pattern and the number of inflammatory cells of WLV-PTC are different from those of PTC-LT or PTC and will be helpful for the differential diagnosis of WLV-PTC in preoperative FNA.

Erdheim-Chester Disease Presenting as an Anterior Mediastinal Tumor without Skeletal Involvement

Erdheim-Chester disease (ECD) is a form of non–Langerhans cell histiocytosis that most commonly involves the skeletal system. We report an unusual case of ECD presenting as an anterior mediastinal tumor without skeletal involvement. A 60-year-old man with no remarkable medical history was referred for evaluation of a mediastinal mass. The patient underwent surgical excision of the tumor via video-assisted thoracoscopic surgery. Histologic examination revealed marked proliferation of atypical histiocytes with sclerosis, and the results of immunohistochemical staining were suggestive of ECD.

A Case of Erdheim-Chester Disease Developed during Treatment of Leukemia in a Child / 임상소아혈액종양

Erdheim-Chester disease (ECD) is a rare non-Langerhan's cell histiocytosis disorder characterized by replacement of normal tissue by lipid-laden histiocytes affecting various organs. A few pediatric cases have been reported worldwide. Here we present a child with leukemia who was diagnosed as ECD. A 2-year and 11-month old boy diagnosed with high risk acute lymphoblastic leukemia (ALL) at the age of 17 months, received allogeneic hematopoietic stem cell transplantation (HSCT) at the age of 2 years old. Six months after the transplantation, the patient was admitted to the hospital with palpable left calf nodules. Bone marrow study suggested ECD without leukemia with complete chimerism status. Excisional biopsy of the left calf nodule showed ‘aggregation of non-Langerhan's cell type epitheloid histiocytes’; clinically suggestive of ECD. The patient was started on vinblastine and corticosteroid treatment.

The Relation between Tympanostomy Tube Otorrhea and Types of Immune Cells in Middle Ear Effusion in Children with Otitis Media with Effusion / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Tympanostomy tube insertion is one of the most common surgical procedures in children. Despite aseptic procedures with prophylactic antibiotic treatment, postoperative otorrhea may be encountered in some patients. The purpose of this study is to identify the relation between the types of immune cells in otitis media with effusion (OME) and tympanostomy tube otorrhea (TTO) in children. SUBJECTS AND METHOD: Fifty-six patients underwent tympanostomy tube insertion with OME were analyzed retrospectively. Fluid from OME was harvested by suction via syringe connector after myringotomy. Light microscopic examination of middle ear effusion was performed by a pathologist after hematoxylin and eosin staining. We analyzed the relation between the types of immune cells from middle ear effusion and TTO. RESULTS: Of 56 children, 36 were male and 22 were female. The mean age for tympanostomy tube insertion was 3.56 (±2.63) years, with the average follow-up period of 12.56 (±9.96) months. Neutrophils were detected in 19, eosinophils in 14, lymphocytes in 22, mast cells in 2, plasma cells in 7, and histiocytes in 9. TTO occurred in 15 patients. In patients with early TTO, eosinophils were detected more frequently than in patients without TTO (p=0.006). Plasma cells were detected more frequently in patient with late TTO than without TTO (p=0.011). CONCLUSION: According to the analysis of different types of immune cells, eosinophils in the middle ear effusion related with the occurrence of TTO.

IgG4-related Ophthalmic Disease Associated with Adult Xanthogranulomatous Disease

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.

Bilateral Frosted Branch Angiitis in Kikuchi-Fujimoto Disease

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.

Sarcomatous transformation of a hemosiderotic fibrohistiocytic lipomatous tumor: a case report / Transformação sarcomatosa de tumor lipomatoso fibro-histiocítico hemossiderótico: relato de caso

ABSTRACT Hemosiderotic fibrohistiocytic lipomatous tumors are rare neoplasms that were first described in 2000. Initially considered a benign lipotamous lesion of the soft tissues, nowadays they are considered to be a locally aggressive tumor. They occur mainly in the foot and ankle of women in their fifth and sixth decades, although they may be found in any place in the lower limbs and, more rarely, in other parts of the body. Histologically, hemosiderotic fibrohistiocytic lipomatous tumors consist of a mixture of mature adipose tissue, fusiform cell fascicles, macrophages that often contain cytoplasmic hemosiderin, mononuclear inflammatory infiltrate, and stroma that may be focally myxoid. Local recurrence is observed in nearly one-third of all cases. There is no consensus in the literature whether this tumor is a part of a spectrum that comprises pleomorphic hyalinizing angiectatic tumors and myxoinflammatory fibroblastic malignant tumors, or if it is an independent entity. The authors report a case of a neoplasia after a diagnosis of a hemosiderotic fibrohistiocytic lipomatous tumor in a 38-year-old woman, with two recurrences and later sarcomatous transformation. An immunohistochemical study indicated myofibroblastic differentiation of a malignant neoplasm. To the best of the authors' knowledge, there are only few reported cases of malignant transformation in hemosiderotic fibrohistiocytic lipomatous tumors.

RESUMO Os tumores lipomatosos fibro-histiocíticos hemossideróticos são neoplasias raras que foram descritas pela primeira vez em 2000. Inicialmente considerada uma lesão lipomatosa benigna dos tecidos moles, atualmente é considerado um tumor localmente agressivo. Essas lesões ocorrem principalmente no pé e no tornozelo das mulheres na quinta e sexta décadas de vida, embora possam ser encontrados em qualquer lugar nos membros inferiores e, mais raramente, em outras partes do corpo. Histologicamente, tumores lipomatosos fibro-histiocíticos hemossideróticos são formados por uma combinação de tecido adiposo maduro, fascículos de células fusiformes, macrófagos que contêm frequentemente hemossiderina citoplasmática, infiltrado inflamatório mononuclear e estroma, que pode ser focalmente mixoide. Há recidiva local em quase um terço dos casos. Não existe consenso na literatura se esse tumor faz parte de um espectro que envolve os tumores angiectásicos hialinizantes pleomórficos e os tumores fibroblásticos mixoinflamatórios malignos ou se configura uma entidade independente. Relatamos um caso de uma neoplasia com diagnóstico inicial de tumor lipomatoso fibro-histiocítico hemossiderótico em uma mulher de 38 anos, com duas recorrências e posterior transformação sarcomatosa. O estudo imuno-histoquímico indicou diferenciação miofibroblástica da neoplasia maligna. Encontramos apenas poucos casos relatados de transformação maligna de tumor lipomatoso fibro-histiocítico hemossiderótico.

Erdheim-Chester Disease with Emperipolesis: A Unique Case Involving the Heart / Journal of the Korean Cancer Association, 대한암학회지

Histiocytosis is an uncommon disease characterized by excessive accumulation of histiocytes. Here, we report a rare case of non-Langerhans-cell histiocytosis in a 51-year-old woman who presented with severe symptoms of pericardial effusion. Radiologic investigation also detected multiple bone (lower limbs, vertebrae, ribs, and ilium) lesions. Resected pericardium showed abundant mono- or multi-nucleated non-foamy histiocytes (CD68⁺/CD163⁺/S-100⁺/CD1α⁻/langerin⁻) in a fibroinflammatory background. The histiocytes demonstrated emperipolesis of lymphocytes, a hallmark feature of Rosai-Dorfman disease (RDD). However, molecular analysis revealed a BRAF V600E mutation of the proliferating histiocytes, highlighting the neoplastic features frequently observed in another non-Langerhans-cell histiocytosis known as Erdheim-Chester Disease (ECD). We consider this case to be a unique presentation of ECD harboring some RDD-like cells with emperipolesis, but not a case of RDD with a BRAF mutation concerning its clinical manifestation (involvement of the heart and bones) and neoplastic features.

A Case of Inflammatory Pseudotumor Cerebri and Nasal Septum / 대한이비인후과학회지

Inflammatory pseudotumors, which clinically mimic neoplasms, are space-occupying collections of inflammatory cells, histiocytes, and fibroblasts. They are most often found in the orbits and lungs, but rarely in the head and neck region, and hardly ever in the nasal septum. Here we report on a 71-year-old woman with pseudotumor cerebri and an inflammatory pseudotumor of the nasal septum. This case demonstrates that inflammatory pseudotumor can cooccur in the brain and nasal septum.

A Case of Intralymphatic Histiocytosis Associated with Breast Cancer / 대한피부과학회지

Intralymphatic histiocytosis (IH) is a rare disease with variable and nonspecific clinical features, but with characteristic histopathological findings. Histopathologically, dilated lymphatic vessels containing aggregates of mononuclear cells are observed near the reticular dermis. IH is often associated with other diseases, such as rheumatoid arthritis, osteoarthritis, joint metal implantation, and with breast cancer where it occurs over the mastectomy scar. Although the pathogenesis of IH is not defined, some authors have suggested that lymphatic vessel engorgement by histiocytes migrating from neighboring inflammatory reactions may play a key pathogenic role. We present a case of IH associated with breast cancer. A 50-year-old female developed multiple tender erythematous plaques on both breasts and the right shoulder 3 years after bilateral mastectomy. To our knowledge, this is the first case of IH in association with breast cancer in the Korean dermatologic literature.