Fibrohistiocytic Tumor Research Articles

Atypical Oral Fibrous Histiocytoma - An Uncommon Histiocytic Lesion Presenting as Inflammatory Fibrous Hyperplasia

Fibrous histiocytoma, as the name suggests, is a lesion which is prominently composed of a combination of fibroblastic & histiocytic cells. Fibrous histiocytoma can usually be seen as either cutaneous types or involving deep tissues. The diagnosis of fibrous histiocytoma is only confirmed after surgical excision. It is imperative to differentiate this lesion from the other aggressive forms of fibrohistiocytic neoplasms. Atypical Fibrous Histiocytoma (AFH) comes in the spectrum of fibrous histiocytic lesion ranging from benign to malignant lesions. Atypical Fibrous Histiocytoma in oral cavity is distinctly uncommon. This uncommon occurrence of the lesion needs to be made known of, to prevent inappropriate treatment. Hence, here we present an uncommon case report of Atypical oral fibrous histiocytoma which presented clinically as epulis fissuratum/ Inflammatory fibrous hyperplasia

Bone tumours-What's new in the 2020 WHO classification and beyond

The recent WHO classification of Bone Tumours (2020) has introduced several changes. Conceptionally, small round cell sarcomas are now summarized in adistinct chapter, acknowledging their occurrence in both, bone and soft tissue. In the light of new molecular findings some diagnostic categories, such as fibrohistiocytic tumors, have been abandoned, and afew new entities have been added to the classification. Finally, systematic changes were made with regard to the terminology employed in the classification of chondrogenic tumours, and modifications have been made with respect to the biological potential of some lesions. This article summarizes the major changes made, underscoring the elementary role of aninterdisciplinary approach in the diagnosis and management of bone lesions.

Case of NSAID- responsive and rapidly-resolving Fibrous histiocytoma

Pediatric fibroblastic, myofibroblastic, and fibrohistiocytic tumors comprise a spectrum of neoplasms of mesenchymal origin. They account for approximately 12% of soft tissue lesions in the pediatric population, and they can be benign, intermediate or locally aggressive, and malignant subtypes. In a diffuse non-skin involving fibrous histiocytoma with inflammatory cells, a trial of said can be considered.

ALK Translocation in ALK-Positive Mesenchymal Tumors: Diagnostic and Therapeutic Insights.

A wide spectrum of mesenchymal tumors harboring ALK gene rearrangements has been identified outside the archetypal example of ALK-positive inflammatory myofibroblastic tumors. To evaluate the molecular pathology of unusual ALK-positive mesenchymal tumors and their response to ALK-targeted treatments. Seven patients with ALK-positive mesenchymal tumors, including inflammatory epithelioid cell sarcoma, undifferentiated sarcoma, histiocytic neoplasm, smooth muscle tumor of uncertain malignant potential (STUMP), and atypical fibrohistiocytic tumor, were included on the basis of aberrant ALK immunoexpression. Patients with inflammatory myofibroblastic tumors were excluded from the study. ALK gene rearrangement was investigated either by fluorescence in situ hybridization or next-generation sequencing. ALK was immunolabeled in all patients, diffusely (≥50%) in 6 patients and partially (10%-50%) in 1 patient. ALK gene rearrangement was discovered in 5 of the 6 available patients. The 3'-partners of ALK fusion were identified in 3 of 4 investigated patients as follows: PRKAR1A-ALK (ALK-positive histiocytic neoplasm), TNS1-ALK (STUMP), and KIF5B-ALK (ALK-positive atypical fibrohistiocytic tumor). We failed to discover ALK translocation in 1 patient with ALK-positive inflammatory epithelioid cell sarcoma. However, transcriptomic investigation showed that this tumor was significantly enriched with ALK-related pathways, which suggested activation of ALK through a nontranslocation pathway, as a constitutive oncogenic mark in this tumor. ALK-targeted inhibitors, which were administered to 3 patients with metastatic diseases, achieved partial remission in 1 patient with ALK-positive inflammatory epithelioid cell sarcoma and stable disease in patients with ALK-positive undifferentiated sarcoma and STUMP. Molecular investigation of ALK-positive mesenchymal neoplasms could allow for an accurate diagnosis and personalized treatment.

SARCOMATOID UROTHELIAL CARCINOMA OF BLADDER - A RARE HISTOLOGICAL VARIANT

Introduction: Urothelial carcinoma (UC) is the most common histological type of bladder cancer. Around 75% of bladder cancers are classified as pure UC, and 25% are urothelial and nonurothelial histological variants. Sarcomatoid UC is a rare variant, accounts for 0.1%–0.3% of all urothelial carcinomas of bladder. It is a biphasic malignant neoplasm with morphologic and immunohistochemical evidence of both epithelial and mesenchymal differentiation. Objective: To study the histomorphological and immunohistochemical features of sarcomatoid urothelial carcinoma. Methods: We received TURBT (Trans Urethral Resection of Bladder Tumor) specimen for histopathological evaluation in the department of pathology, DY Patil medical college, Kolhapur. Routine tissue processing of bits was done and H & E stained sections were subjected for detailed microscopic evaluation and various immunohistochemical markers were applied on the paraffin embedded tissue blocks. Results: A95years old female patient presented with hematuria and anemia.On cystoscopy polypoidal lesion seen in the lateral wall of urinary bladder.No history of previous surgery on urinary bladder.TURBT done. On gross, there were multiple, irregular, grey white strips of tissue altogether weighing 160gms. On microscopy, neoplasm with papillary architecture was seen invading lamina propria. Chondromyxoid, rhabdoid and malignant fibrohistiocytic tumor like areas noted. Immunohistochemical workup revealed positive staining with cytokeratin, vimentin and GATA3 and negative with H-Caldesmon, SMA and Myogenin. Conclusion: Sarcomatoid UC is seen in elderly. Morphologically, the lesion mimics sarcoma, immunohistochemistry workup aids in definitive diagnosis, as it has poor prognosis compared to pure UC.

Plexiform Fibrohistiocytic Tumour at a Rare Site: Frontal Region of Head with Underlying Frontal Bone Invasion

Plexiform Fibrohistiocytic Tumour (PFHT) is an intermediate malignant tumour of soft tissue. It is a rarely metastasising dermal subcutaneous neoplasm. It affects children and young adults. The age range of presentation is from birth to age 77 years. The tumour is most commonly located on the upper extremities, whereas the involvement of the frontal region is rare. The differential diagnosis includes benign fibrous histiocytoma, fibromatosis, giant cell tumour and neurofibroma. Plexiform fibrohistiocytic tumour is a slow-growing mass and which is considered a low grade malignant tumour. Treatment is simple excision. It can exhibit aggressive behaviour and rate of local recurrence is 12-38%. A 45-year-old female was presented with a solid mass on the frontal region of the head which was diagnosed as a plexiform fibrohistiocytic tumour with underlying frontal bone invasion on histopathological examination of an excised mass in the Pathology Department. Plexiform Fibrohistiocytic Tumour (PFHT) is a mesenchymal neoplasm that shows a multinodular growth pattern and which is composed of fibroblasts, histiocyte-like cells and multinucleated osteoclast like giant cells. Clinically, it is usually a slow-growing mass with frequent local recurrence and rare regional lymphatic and systemic metastasis.

PRAME expression in cellular neurothekeoma: A study of 11 cases.

Preferentially expressed antigen in melanoma (PRAME) has been widely investigated in the skin, mainly in melanocytic tumors, and constitutes an aid in differentiating benign from malignant lesions. Very few studies have been performed on non-melanocytic tumors. We investigated the immunohistochemical expression of PRAME on a series of 11 neurothekeomas (NTKs), together with 3 cases of nerve sheath myxoma (NSM) and 1 case of plexiform fibrohistiocytic tumor (PFT), in order to evaluate the presence and usefulness of this marker in their differential diagnosis. PRAME was variably expressed in all cases of NTK, with moderate intensity in three cases and faint in the remaining cases; on the contrary, cases of NSM and PFT were negative. This study expands the entities of cutaneous non-melanocytic tumors expressing PRAME, and confirms that this marker is not restricted to malignant tumors. Expression of PRAME in NTK does not seem to be related to distinctive histopathologic features.

Giant cell tumor of soft tissue: FNA cytopathology of 4 cases, review of the literature, and comparison with giant cell tumor of bone.

The cytopathology of a giant cell tumor of soft tissue (GCT-ST), a fibrohistiocytic neoplasm distinct from other giant cell-rich soft tissue tumors, is rarely reported. The authors report their experience with a series of 4 GCT-ST fine-needle aspiration (FNA) biopsy cases and compare them with a set from giant cell tumors of bone (GCTBs). The authors' cytopathology files were searched for GCT-ST examples with histopathologic confirmation. FNA biopsy smears were performed and examined with standard techniques. Four cases of GCT-ST presenting as a primary soft tissue mass from 4 patients (3 males and 1 female; age range, 28-75 years, mean age, 53 years) were retrieved. FNA sites included the anterior tibia, buttock, shoulder, and upper back. Three cases were interpreted as suspicious for sarcoma radiographically. The specific diagnoses were atypical giant cell tumor of tendon sheath, suspicious for GCT-ST, atypical myxoid lesion with giant cells, and benign with osteoclast-like giant cells (OLGCs). No case was interpreted as malignant. Aspirates consisted of mononuclear polygonal cells, spindled fibroblast cell clusters, and large OLGCs to the near exclusion of other cell types. OLGCs possessed 10 or more nuclei per cell. A comparison with GCTB aspirates and single case reports from the literature showed comparable cytomorphology. GCT-ST FNA smears mimic those of GCTBs containing a limited population of uniform spindle cell clusters, single dispersed polygonal cells, and cytologically banal OLGCs. GCT-ST should be considered in the differential diagnosis of aspirates containing numerous osteoclast-like giant cells.

Diagnostic and Management Considerations in Pediatric Dermatofibrosarcoma Protuberans.

Dermatofibrosarcoma protuberans (DFSP) is a rare fibrohistiocytic tumor of dermal origin. Six percent of all cases present in children, with a childhood incidence of 1 per million. This is a retrospective review of all cases of pediatric DFSP managed at a single institution over a 23-year period. Seventeen patients (10 male; mean age, 9.9 years) were managed during the study period. The median follow-up was 29 months. All patients had surgical excision. Three patients required further excision to achieve uninvolved final margins. There were no recurrences observed. Pediatric DFSP should be managed by a soft tissue tumor multidisciplinary team, with experienced pathologists and reconstructive surgeons. Where R0 resections are obtained, patients can experience recurrence-free survival.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 2: vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas.

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous organ soft tissues, as well as the peripheral and autonomic nervous system.

Update on Superficial Spindle Cell Mesenchymal Tumors in Children.

The diagnosis of cutaneous and subcutaneous spindle cell neoplasms in children is often challenging and has potential therapeutic and prognostic implications. Although correctly diagnosing dermatofibrosarcoma protuberans and infantile fibrosarcoma is paramount, pathologists should not ignore a number of diagnostic pitfalls linked to mostly rare tumors with completely different clinical outcomes. In the last decade, a spectrum of novel entities has been described; information from molecular biology has helped to shape this new landscape for spindle cell tumors. Here, we review the most noteworthy neoplasms in this spectrum, with a focus on their histological similarities: fibroblastic connective tissue nevus, medallion-like dermal dendrocyte hamartoma, or plaque-like CD34-positive dermal fibroma, which share features with fibrous hamartoma of infancy; lipofibromatosis and lipofibromatosis-like neural tumor; and plexiform myofibroblastoma, a recently described neoplasm that should be distinguished from plexiform fibrohistiocytic tumor. These tumors also have genetic similarities, particularly gene rearrangements involving NTRK3 or NTRK1. These genetic features are not only essential for the differential diagnosis of infantile fibrosarcoma but are also of diagnostic value for lipofibromatosis-like neural tumors. The more recently described RET, RAF1, and BRAF gene fusions are also discussed.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 1: tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors.

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous-organ soft tissues, as well as the peripheral and autonomic nervous system.

Tumor fibrohistiocítico plexiforme. Serie de dos casos.

Resumen El tumor fibrohistiocítico plexiforme (TFHP) es una neoplasia mesenquimatosa rara de malignidad intermedia, informada por primera vez por Enzinger y Zhang en 1988. Tiene predilección por niños y adultos jóvenes, pero puede ocurrir a cualquier edad. Suele afectar a extremidades superiores y se presenta como una masa indolora de crecimiento lento. Tiene una alta tasa de recurrencia local y la aparición de metástasis es excepcional. Histológicamente, se caracteriza por una masa dérmica o subcutánea mal demarcada con crecimiento plexiforme multinodular y citomorfología fibrohistiocítica. Se requiere una resección quirúrgica completa de la lesión, preferiblemente con márgenes amplios, para prevenir la recurrencia local. Es necesario un seguimiento a largo plazo para detectar cualquier metástasis nodal o pulmonar. Presentamos una serie de dos casos de TFHP que precisaron de ampliación de márgenes quirúrgicos.

Histological spectrum of benign soft-tissue neoplasm in a tertiary care center

Background: Benign soft-tissue tumors are very frequently received specimen in surgical pathology as compare to malignant one. Aims: The purpose of the study is to calculate the incidence and prevalence of benign soft-tissue tumors, to calculate their frequency in different age, sex, and site distribution in tertiary care hospital, and to study their different histological types. Subjects and Methods: We studied all soft-tissue tumors received in histopathology department in 4 years. All clinical parameters such as age, sex, incidence, site and size of swelling, gross, and microscopy of the lesions were studied carefully. Statistical Analysis Used: Data were analyzed using a Chi-square test. Results: Total 360 (9.9%) soft-tissue tumors were received, 330 (91.7%) were benign, and 30 (8.3%) were malignant. The incidence of benign and malignant tumors was more common in males (55.8%) than in females (44.2%). The peak incidence of benign tumors was in 21–30 years. The most common site for benign tumors was the extremities, followed by head and neck. Lipomas formed major bulk of benign tumors (52.4%), followed by vascular tumors (21.2%), peripheral nerve sheath tumors (20.9%), fibrous tumors (3.3%), fibrohistiocytic tumors (1.8%), smooth muscle tumors and tumors of uncertain differentiation (0.3%) in descending order. Conclusions: Benign soft-tissue tumors were most commonly occurring lesions in clinical practice. From this study, we were re-evaluate the clinical data of benign soft-tissue tumors, there histological types along with age, sex, and site distribution.

Ecografía del tumor fibrohistiocítico plexiforme en edad pediátrica

Ecografía del tumor fibrohistiocítico plexiforme en edad pediátrica

Pitfall regarding expression of ETS‐related gene (ERG) in fibrohistiocytic neoplasms

Pitfall regarding expression of <scp>ETS‐related gene (ERG)</scp> in fibrohistiocytic neoplasms

Hand Masses.

Hand and wrist soft tissue masses may be classified as pseudotumors, benign neoplasms, or malignant neoplasms. The vast majority of hand lesions are benign. Consideration of the location of the lesion and its imaging characteristics often leads to a specific diagnosis. Pseudotumors discussed in this article are ganglion cysts, accessory muscles, and inflammatory lesions. True tumors are described according to their tissue type: nerve sheath tumors, adipocytic tumors, so-called fibrohistiocytic tumors, pericytic tumors, and vascular lesions. We also outline the imaging features of masses encountered in the hand and wrist.

Comparative expression profile of CD10 and cyclin D1 in cutaneous histiocytofibroma and dermatofibrosarcoma

ABSTRACT Dermatofibrosarcoma protuberans (DFSP) and histiocytofibroma (HF) are two rare fibrohistiocytic tumors, with some overlapping pathologic features. Immunohistochemistry is very useful in these cases. CD34 is a commonly used marker. However, the increasing cases of CD34 negative DFSP make it pressing to test other immunohistochemical markers that could help in the differential diagnosis. DFSP is known to harbor COL1A1-PDGFB rearrangement. Tumors in the differential diagnosis of DFSP usually lack this molecular signature. Recent studies suggested the interaction of PDGFB and PDGF receptor b with various signaling pathways, including the Akt-mTOR pathway. Cyclin D1, one of the oncoproteins activated in this pathway, may represent a promising useful biomarker in the differential diagnosis. On the other hand, CD10 expression in specialized mesenchymal skin cells, and especially in fibrohistiocytic skin tumors has been reported, which raises the interest of using this biomarker in HF and DFSP. In this study, we aimed to compare the expression of CD10 and cyclin D1 in 15 cases of DFSP and 15 cases of HF and discuss their potential contribution in the differential diagnosis.

Cytopathology of myxoinflammatory fibroblastic sarcoma: a series of eight cases and review of the literature

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare low-grade sarcoma presenting as a slow-growing mass that occurs mainly in the distal extremities of adults. Relatively little is known about the cytopathology of MIFS. We evaluated cytologic characteristics of MIFS on fine-needle aspiration (FNA). A search was made of our cytopathology and surgical pathology databases for cases diagnosed as MIFS. FNA biopsy smears and cell-block were performed and examined using standard technique. Eight cases were retrieved from patients aged 22-90 years (mean, 56 years), and M:F ratio of 1:1. Six tumors (75%) were primary, and 2 (25%) locally recurrent. Distal lower limb was involved in all but one case (88%). One (13%) recurrent case was correctly diagnosed cytologically as MIFS; remaining single diagnoses were varied: myxofibrosarcoma, low-grade sarcoma, malignant neoplasm, myxoid neoplasm, atypical fibrohistiocytic neoplasm, atypical cells with chronic inflammation, and spindle cells with atypia. Among 7 cases with available cytologic slides for review, common features were spindle cells with variable atypia (100%), rare virocyte/Reed-Sternberg -like cells (86%), background mixed inflammation (71%), and variable myxoid stroma (57%). Pseudolipoblasts and multinucleated giant cells were rare. Hemosiderin and branching capillaries were largely absent. Immunohistochemistry was non-specific. MIFS was accurately interpreted in only 13% of cases; remaining cases were diagnosed as atypical or malignant, which would lead to proper management. A specific cytologic diagnosis of MIFS using FNA is extremely difficult in our experience due to an absence of distinctive cytomorphology and specific immunophenotype.

Primary breast stromal sarcoma: A rare case report

Primary sarcoma of the breast comprises less than 1% of all the breast malignancies. It is a locally aggressive neoplasm with only a few hundred cases published till date. The index case is being reported due to rarity of this entity. Breast sarcoma should always be considered whenever spindle cells are seen in the histological sections. The main diagnostic confusion arises with malignant phyllodes tumor and metaplastic carcinoma from which distinction is important from prognosis as well as treatment point of view. Herein, we report a case of a 47-yr-old female, who presented with a right-sided breast lump which was diagnosed as suspicious of carcinoma breast on fine needle aspiration (FNAC). Thereafter, modified radical mastectomy was performed, and on histopathology, a possibility of fibro-histiocytic tumor of intermediate malignancy was rendered, which was subsequently confirmed by immunohistochemistry (IHC).