Recurrent benign fibrous histiocytoma of the bone benefits from denosumab followed by malignant transformation: a case report.

Benign fibrous histiocytoma of the bone (BFHB) is a rare mesenchymal tumor, representing less than 1% of all benign bone tumors. This controversial entity is characterized by a mixture of fibroblasts arranged in a storiform pattern, varying amounts of osteoclast-type giant cells and foamy macrophages. Curettage or simple resection is usually curative. However, it was reported that up to 11% of the patients suffer from relapse. Here, we report a case of malignant transformation of BFHB after long-lasting disease stabilization under denosumab therapy.

168 Cases of aneurysmal dermatofibroma and 29 cases of hemosiderotic dermatofibroma: A clinicopathologic study.

OBJECTIVES: Aneurysmal dermatofibroma (ADF) and hemosiderotic dermatofibroma (HDF) are rare variants of dermatofibroma (DF) characterized by distinct histologic features. While HDF is traditionally considered a precursor to ADF, supporting evidence is limited, and the etiology remains unclear. A retrospective analysis of 2128 DF cases (2016-2019) was conducted to investigate the clinicopathologic characteristics of ADF, HDF, and other DFs. METHODS: Histopathologically diagnosed DF cases were examined for ADF and HDF. Univariate analyses were performed to compare clinicopathologic features. RESULTS: Among the cases, 168 (7.9%) were ADF and 29 (1.4%) were HDF. Aneurysmal dermatofibroma and HDF shared several common characteristics, including lower occurrence in females, larger size, and increased cellularity (all P < .0001). Notably, 29% of ADFs lacked hemosiderin deposition. Aneurysmal dermatofibroma primarily manifested on exposed areas (face and forearm, both P < .001). In contrast, 41% of HDFs occurred on the lower leg (P = .018), and all lower leg HDFs exhibited signs of venous stasis, distinguishing them from other HDFs (P < .0001). CONCLUSIONS: Our findings indicate a potential close relationship between ADF and HDF. Contrary to conventional beliefs, we also presented the possibility of ADF progressing into HDFs. Physical trauma may induce ADF, and HDFs may emerge from ADFs in conjunction with venous stasis in the lower extremities.

Epidermal inclusion cyst embedded in benign fibrous histiocytic lesion with prominent epithelioid morphology.

Benign fibrous histiocytoma also known as dermatofibroma is one of the common mesenchymal neoplasms. It commonly develops in young adult with female predominance and predilection for the extremities, particularly lower extremities. Implantation of epidermis in the dermis or subcutaneous tissues may lead to the formation of epidermal inclusion cyst, which is the most common type of epithelial cyst. Development of epidermal inclusion cyst within a benign fibrous histiocytoma is a rare occurrence. This is a unique case of two unrelated lesions.

Giant Cell Tumor of Lumbar Vertebrae on MR and 18F- FDG PET/CT: A Case Report and Literature Review.

Teaching Point: Giant cell tumor of bone may show a moderate to high FDG uptake, and attention should be paid to differentiate from malignant tumors.

Keloidal dermatofibroma: Clinicopathological comparison of 52 cases with a series of 2077 other dermatofibromas.

Dermatofibroma is a common benign skin lesion with a contested etiology: some believe it is a neoplasm while others propose minor injuries initiate it. Many dermatofibroma variants have been described, including keloidal dermatofibroma, which is unusual by bearing keloidal collagen. Keloidal dermatofibroma was first described in 1998 and only 15 cases have been reported. Since keloids are driven by skin injuries, the existence of keloidal dermatofibroma has been suggested to support the injury hypothesis of dermatofibroma etiology. To better understand keloidal dermatofibroma characteristics and gain clues regarding dermatofibroma etiology, consecutive keloidal dermatofibroma cases (n = 52) and dermatofibroma without keloidal collagen (n = 2077) that were histopathologically diagnosed in 2016-2019 were identified from the records of a Japanese dermatopathology laboratory and compared in terms of demographic, clinical, and histopathological characteristics by univariate analyses. Compared to other dermatofibromas, keloidal dermatofibromas occurred more frequently on the forearm and hand (P < 0.0001 and 0.0019), especially the wrist dorsum, and in the superficial skin layer (P < 0.0001). Keloidal dermatofibromas also demonstrated more cellularity and hemorrhage (both P < 0.0001). Correlation analyses between keloidal collagen amount and keloidal dermatofibroma size (a proxy of time-since-onset) did not support the notion that keloidal collagen deposition and keloidal dermatofibroma formation are triggered simultaneously. Recent injury, as indicated by fresh hemorrhage, was equally common in putatively older and younger keloidal dermatofibromas. Thus, keloidal collagen in keloidal dermatofibromas could be due to injury to preexisting dermatofibromas, which suggests that the keloidal dermatofibroma entity does not prove the injury hypothesis. Commonalities between keloids and keloidal dermatofibromas suggest a link between genetics, provocative events that induce myofibroblast differentiation, and keloidal collagen production.

Benign Fibrous Histiocytoma of Larynx: A Rare Case Report.

The Fibrous histiocytoma is one of the mesenchymal tumors that can present as malignant or benign. We reported a 30 years old male, a rare case of benign fibrous histiocytoma of larynx and evaluated the clinical and histological aspect of this patient.

Multiple benign fibrous histiocytomas of the mandible: A case report and review of the literature.

Benign fibrous histiocytoma (BFH) mostly occurs on the skin of the extremities, while it is unusual to manifest on the bone and mandibular involvement of BFH is even rarer. The present study reports a case of BFH in a 42-year-old female who had a slowly progressive swelling of the bilateral mandible and slight facial asymmetry over a period of 4 months. However, the outcome of this patient was unsatisfactory, with the first and second recurrence observed 16 and 46 months after surgery, respectively. The present case suggests that BFH has a risk of recurrence after transoral curettage. Regular follow-up is advised to detect tumor recurrence after the surgery of transoral curettage.

Giant cell tumor of bone in an eighteenth-century Italian mummy.

Giant cell tumor (GCT) of the bone is a locally aggressive and rarely metastasizing neoplasm. It is composed of neoplastic mononuclear stromal cells with a monotonous appearance admixed with macrophages and osteoclast-like giant cells. In a small subset of cases, GCT is malignant. Terminology previously related to this entity, and which is no longer supported by the World Health Organization, includes osteoclastoma and benign fibrous histiocytoma (BFH). Giant cells occur in numerous other pathologic conditions of the bone, which accounts for the misrepresentation of these non-GCT tumors in the early literature. Non-ossifying fibroma (NOF), aneurysmal bone cyst, and chondroblastoma have been erroneously labeled GCT for this reason. A single description of an ancient GCT was reported by Brothwell and Sandison and subsequently mentioned by Aufderheide and Rodrìguez-Martìn who were astonished that more of these tumors had not been identified in archaeological cases. To the best of our knowledge, no other cases of ancient GCT have been cited in the paleopathology literature. The study of this type of neoplasm in antiquity can be used as a means to better understand its characteristics and behavior and to expand the depth of time of the etiology of these lesions. We report a case of GCT of the left femur observed following the total body CT imaging of a partially mummified adult female, dating to eighteenth century.

Conjunctival and Corneal Fibrous Histiocytoma: Brief review.

Background: Fibrous histiocytoma (FH), a mesenchymal tumour, usually have an orbital presentation. Rarely, FH in both benign and malignant forms have been reported at limbus and conjunctiva. Present narrative review was conducted to determine demographic profile, clinical presentation and management options for this rare tumour.Methods: PubMed database was searched to identify articles presenting with fibrous histiocytoma of conjunctiva, cornea and limbus. Data was tabulated for age of presentation, sex, eye involved, area of involvement, if tumor was benign or malignant, management and recurrences.Results: Total of 35 articles were selected, which included 42 cases, of which 27 were benign and 15 malignant. 25 cases showed presence of limbal FH, 12 conjunctival, 4 caruncular and 1 corneal FH. Mean age of presentation was 30.9 years with male preponderance (females-10, males-17) in benign FH while malignant FH presented with mean age of 44.5 years and sex distribution of 7 females and 8 males. 4 cases of benign FH showed recurrence, which required re-excision and immunotherapy, while recurrence in malignant FH was 60%, where 4 needed exenteration, 3 enucleation and 1 expired due to metastasis.Conclusion: FH is one of the rare ocular tumours of eye presenting usually at the limbus and conjunctiva and rarely cornea. Histopathological examination along with immunostaining has a definite role in the diagnosis. Surgical excision with tumour free margins is the corner stone of treatment. Recurrences in benign varieties need re-excision or immunotherapy, while malignant cases need aggressive surgical options like exenteration or enucleation.

A Clinicohistopathological Analysis of Cutaneous Fibrous Histiocytomas of the Finger.

BACKGROUND: Cutaneous fibrous histiocytoma (CFH) is a common, benign skin tumor predominantly occurring on the extremities or trunk. However, CFH on the finger is rare. OBJECTIVE: This study was undertaken to examine the clinicohistopathological features of CFH of the finger. MATERIALS AND METHODS: This is a retrospective study of 12 CFHs located on fingers in a tertiary hospital in Korea. All case slides were retrieved from saved files. RESULTS: Ages of the CHF of the finger affected individuals ranged from 9 to 48 years with a male-to-female ratio of 1.4:1. Picker's nodule or wart was the most common clinical diagnosis. In only 2 out of the 12 cases was the pre-biopsy diagnosis of CFH ventured. Fibrocollagenous type was the most common histological type. Majority of the cases were mitotically inactive, exhibiting only 0-1 mitoses per high-power field and there was no recurrence. Tumor cells were uniformly CD34 negative. CONCLUSION: Because CFH can resemble malignancies including dermatofibrosarcoma protuberans, a lack of familiarity with the occurrence of CFH of the finger may lead to more aggressive treatment. Dermatologists should include CFH in their differential diagnosis of circumscribed nodules on the fingers to ensure proper management.

Solitary adult xanthogranuloma in external auditory canal: Cyto-histopathological correlation of an uncommon entity at an uncommon site.

Juvenile xanthogranulomas (JXG) are the most common type of self-limiting non-Langerhans cell histiocytosis (LCH) usually presenting in infancy and early childhood. Clinically, they present as solitary to multiple rounded cutaneous nodules which resolve over time. Adult type xanthogranulomas (AXG), though histologically similar to JXG, are usually single and do not regress spontaneously. AXG arising in the external auditory canal (EAC) is a rare occurrence with very few cases reported in literature. We present a case of AXG in a 48-year-old man, arising from the right EAC. This case is unique as it is the only case to be described with both cytology and histology correlation. On cytology, smears showed scattered foamy histiocytes, inflammatory cells and thick stromal fragments. Cytology differential diagnoses of xanthomatous lesion, benign fibrous histiocytoma (BFH) and ceruminous adenoma were given; final diagnosis was deferred to histopathology which confirmed it to be an AXG. Thus, it is important to keep the diagnosis of AXG in mind while dealing with solitary polypoidal lesions in EAC showing prominent foam cell component. Lipidised BFH forms a close differential diagnosis, however can be excluded by subtle points on cytology and on histopathology.

A rare presentation of benign fibrous histiocytoma in the maxilla.

Fibrous histiocytoma is a soft-tissue tumor that may present as a fibrous mass anywhere in the human body. The involvement of the oral cavity is rare. We here report a case of benign fibrous histiocytoma localized in the maxilla. A 25-year-old male presented with a slowly increasing large painless mass over the left side of the upper jaw for 5 months. The swelling was of gradual onset, slowly progressive and was not associated with pain, tenderness, or discharge. The radiographic appearance showed a multilocular mixed radiodense, radiolucent lesion in the left posterior maxilla. The histopathological report showed connective tissue component having streaming fascicles of spindle-shaped cells showing a storiform pattern. Many areas showed foamy histiocytes along with few multinucleated giant cells. The cells were appearing benign without any appearance of atypia. The tumor cells were positive for CD-68 and vimentin and negative for CD-34 and S100. The lesion was excised under general anesthesia.

Benign fibrous histiocytoma of the lower lip.

The fibrous histiocytoma is a soft-tissue neoplasm of the biphasic cell population of fibroblasts and histiocytes that affects the dermis and the subcutaneous tissue. The objective of this article is to report a case of benign fibrous histiocytoma (BFH) of the lower lip in a 32-year-old female patient with a chief complaint of swelling in the lower lip for the past 1 month. With diagnostic clinical hypothesis of fibrous hyperplasia, fibrous histiocytoma and mucocele, an excisional biopsy was performed. The histopathological examination revealed a nonencapsulated proliferation of spindle cells with some giant multinucleated cells in the periphery of the lesion. Multinucleated giant cells and lymphocytes were noted throughout the lesion. Immunohistochemical reactions were performed, staining only CD68 in the multinucleated giant cells. According to these characteristics, the final diagnosis was BFH.

The first total vertebral involvement of benign fibrous histiocytoma: A case report and literature review.

BACKGROUND: Benign fibrous histiocytoma (BFH) is a rare bone tumor, extremely seldom in the spine. METHODS: We present a 52-year-old patient diagnosed with a BFH in the thoracic spine treated with total en bloc spondylectomy. A review of the published literature was also conducted. RESULTS: Non-ossifying fibroma (NOF) and BFH are named as one tumor called NOF/BFH. A total of 20 spinal BFHs have been previously reported, mainly involving the posterior elements. We present a BFH with total vertebral involvement. Curettage and excision are the main treatment options with limited recurrence. CONCLUSIONS: This is the first total vertebral BFH up to now. Spinal BFH occupies rather low aggressiveness. With rather limited recurrence and malignant degeneration, surgical interventions seem enough for its management.

Primary Intraosseous Xanthomas of the Jaws: A Series of Six Cases Including an Example with Formation of Apoptosis-Related Hyaline Globules, So-Called "Thanatosomes".

Primary intraosseous xanthomas of the jaws (PIXJ) are rare and predominantly affect the posterior mandible (86%) of normolipemic patients, with a mean age of 30 years and no gender predilection. Clinically, PIXJ exhibit indolent biologic behavior; curettage is considered treatment of choice. Only 36 PIXJ have been reported. Apoptosis-related hyaline globules (HGs), also known as "thanatosomes", have not been previously reported in PIXJ. Cases diagnosed as xanthoma of bone were retrieved. Six cases fulfilling currently accepted criteria were identified and their clinicopathologic and immunohistochemical properties are presented herein. Mean age for PIXJ was 21.8 years (range = 12-33) and F:M ratio = 2:1. All cases presented as well-demarcated, unilocular or multilocular radiolucencies. Microscopically, PIXJ featured sheets of lipid-laden macrophages with eosinophilic or foamy cytoplasm. A secondary fibroblastic population lacking storiform pattern was evident in two cases. Adipocytes (3/6), peripheral neurovascular bundles (1/6), bone fragments (3/6) and dystrophic calcifications (3/6) were observed enclosed by the xanthoma cells. Notably, one case exhibited numerous, spherical, eosinophilic HGs containing apoptotic nuclei. PIXJ were consistently CD68(+) and negative for CD1α and S100. CD45 decorated lymphocytes and the membrane of foamy histiocytes. Xanthoma cells stained for lysozyme and plasma proteins including alpha-1 antitrypsin (AAT), IgG and IgA in one probed case. HGs were lysozyme(+), AAT(+), IgG(+), IgA(+), PAS(+) and diastase-resistant, and fuchsinophilic with Masson's trichrome. PIXJ represent infrequent, solitary, mandibular lesions with a predilection for the second and third decade of life. Thanatosomes associated with cell injury and death can be present in PIXJ.

Benign fibrous histiocytoma of the maxilla: A rare case report and literature review.

Benign fibrous histiocytoma (FH) is a benign soft-tissue tumor that can present as a fibrous tissue mass anywhere in the body. The involvement of the paranasal sinuses is extremely rare, and very few cases have been reported in literature till date. We here report a case of benign FH localized in the maxillary sinus. The clinical and histological features of the lesion are discussed with a brief literature review of this pathology in the paranasal sinuses.

Aneurysmal benign fibrous histiocytoma of the anal canal: a rare differential diagnosis.

BACKGROUND: To our knowledge, we report the first case of an aneurysmal benign fibrous histiocytoma occurring in the anal canal. METHODS: Clinical, histological, radiological and surgical data pertaining to this patient were analysed. Additionally, a literature review on aneurysmal benign fibrous histiocytoma was conducted. RESULTS: We describe a 48-year-old Caucasian male presenting with a 2-week history of a painful anus, fresh rectal bleeding and tenesmus. Digital rectal examination identified a tender firm mass in the anal verge. Magnetic resonance imaging revealed high signal in the anal canal. Flexible sigmoidoscopy revealed an ulcerated 3-cm indurated lesion at the four o'clock position. Biopsies taken of the mass confirmed the diagnosis of an aneurysmal benign fibrous histiocytoma (BFH). Following a discussion in the colorectal multi-disciplinary team, the patient was counselled for an excision of the lesion. Diathermy dissection was performed to completely excise the tumour with a margin involving the fibres of the anal sphincter. The patient made a full recovery and had no residual symptoms. Histology of the excised specimen confirmed clear margins of the BFH. CONCLUSIONS: This paper aims to highlight a rare differential diagnosis for an anal mass. An aneurysmal BFH most often presents as a painless mass within the dermis and subcutaneous tissue. As such, this case presents a diagnostic challenge to both colorectal surgeon and histopathologist due to its low incidence and unusual location. We further present the clinical and radiographic evidence to confirm the diagnosis. Additionally, we discuss the literature pertaining to this condition and its optimal management.

First report of hemosiderotic adenodermatofibroma in Brazil / Primeiro relato de adenodermatofibroma hemossiderótico no Brasil

ABSTRACT Hemosiderotic adenodermatofibroma is a recently recognized lesion, characterized by a dermal nodule with cystic structures of an apocrine gland, surrounded by a dermatofibroma-like stroma with hemosiderotic macrophages. We present the first case report of this entity in Brazil together with representative images, in addition to a review on the subject and discussion about the apocrine origin of this lesion.

RESUMEN El dermatoadenofibroma hemosiderótico es una lesión recientemente descrita, caracterizada por un nódulo dérmico con estructuras quísticas de una glándula apocrina, rodeado por un estroma del tipo dermatofibroma con macrófagos hemosideróticos. Presentamos el primer reporte de caso de esa entidad en Brasil, junto a imágenes representativas, además de una revisión del tema y discusiones acerca del origen apocrina de esa lesión.

RESUMO Adenodermatofibroma hemossiderótico é uma lesão recentemente conhecida, caracterizada por um nódulo dérmico com estruturas císticas de uma glândula apócrina, circundado por um estroma do tipo dermatofibroma com macrófagos hemossideróticos. Apresentamos o primeiro relato de caso dessa entidade no Brasil junto a imagens representativas, além de uma revisão do assunto e discussões sobre a origem apócrina dessa lesão.

Conjunctival Benign Fibrous Histiocytoma in a 57-year-old man.

Purpose. To report a case of benign fibrous histiocytoma of the conjunctiva involving the cornea, an uncommon ocular surface tumor. Methods. A 57-year-old patient came in our service complaining of a progressively enlarging conjunctival mass temporally to the limbus and invading the adjacent cornea of the left eye. Results. The approach consisted in surgical excision followed by cryotherapy on the edges and on the base of the excision site and amniotic membrane patch reconstruction of the ocular surface defect. Pathologic examination and immunohistochemistry were performed in order to establish the diagnosis. No recurrences appeared in 8 months of follow up. Conclusions. Fibrous histiocytoma might be easily misdiagnosed as it is exceedingly rare. Complete resection with careful inspection of edges is advised. Cryotherapy at the base and borders of the resection site is recommended as both benign and malignant tumors can show recurrence. Amniotic membrane should always be regarded as an efficient option in reconstruction of broad surface defects after tumor resection. Abbreviations: FH = fibrous histiocytoma, CIN = corneal intraepithelial neoplasia, SSCA = squamous cell carcinoma, AM = amniotic membrane, MMC = topical mitomycin-C, 5-FU = 5-fluorouracil, BCVA = best corrected visual acuity.

A rare case of benign fibrous histiocytoma of the cornea.

Fibrous histiocytoma (FH) commonly occurs in the superficial layers of the skin. Orbit and limbus are documented ophthalmic sites of involvement but isolated corneal FH has never been reported in literature. We present the first case of FH exclusively involving the cornea where a 10-year-old male child presented with a 3-month history of a painless growth on the superior cornea of the right eye with deterioration of vision. Tumor excision with therapeutic penetrating keratoplasty was done and the histopathological examination confirmed the diagnosis. There was no recurrence and the corneal graft was clear at 1 year.