Primary Pulmonary Myxoid Sarcoma and Thoracic Angiomatoid Fibrous Histiocytoma: Two Sides of the Same Coin?

Primary pulmonary myxoid sarcoma (PPMS) and thoracic angiomatoid fibrous histiocytoma (AFH) are rare neoplasms with EWSR1 fusions and overlapping morphology. Both tumor types often show epithelial membrane antigen expression, but AFH characteristically co-expresses desmin. We encountered a case of PPMS with the unexpected finding of patchy, strong anaplastic lymphoma kinase (ALK) (previously reported in AFH) and synaptophysin expression. We evaluated a cohort of PPMS and thoracic AFH with systematic morphologic comparison and surveyed for aberrant expression of ALK and synaptophysin. Medical records and slides were reviewed for 16 molecularly confirmed cases of PPMS (n=5) and thoracic AFH (n=11). Each case was scored for morphologic characteristics typical of PPMS and/or AFH. ALK, synaptophysin, chromogranin, desmin, and epithelial membrane antigen immunostains were performed on cases with available tissue. AFH and PPMS cases showed similar age at presentation and long-term tumor behavior. Almost all cases of PPMS and AFH had a fibrous pseudocapsule and lymphoid rim. All PPMS had myxoid stroma and reticular growth pattern, but these features were also present in a subset of AFH. Synaptophysin expression was present in 6 of 11 AFH and 1 of 5 PPMS; all tested cases were negative for chromogranin (n=15). One case of AFH and 1 case of PPMS showed focally strong coexpression of synaptophysin and ALK. AFH and PPMS show considerable clinicopathologic overlap. When supportive, the immunohistochemical findings described may aid in diagnosis before molecular confirmation. PPMS and AFH may be morphologic variants of the same clinicopathologic entity, which can show more immunophenotypic variability than previously reported.

The many faces of Atypical fibroxanthoma.

Atypical fibroxanthoma (AFX) is an uncommon, primary dermal neoplasm of uncertain histogenesis, typically originating in the sun-damage skin of the head and neck of the elderly. Since first description in 1958, ∼3000 cases have been reported in the literature. However, the disease is underreported as the neoplasm is considered a standard diagnosis in the last decades. On the other hand, many earlier reports likely have included non-AFX mimics or aggressive pleomorphic dermal sarcomas. In contrast to its alarming high-grade histology, AFX behaves indolently with rare recurrences/ metastatic rate of <2%. The overall 10- and 20-year disease-specific survival rates are ∼ 100% and 98%, respectively. Histologically, AFX displays undifferentiated pleomorphic spindle cell morphology akin to undifferentiated pleomorphic sarcoma (UPS), a feature that was the basis of the abandoned historical terminology "MFH of skin". However, in contrast to other undifferentiated sarcomatoid neoplasms, AFX is notorious for its highly variable histology with a plethora of patterns, underlining a wide differential diagnosis. Notably, spindle cell, keloid-like, pleomorphic, epithelioid, rhabdoid, clear cell, foamy cell, granular cell, bizarre cell, pseudoangiomatous, inflammatory, osteoclast-rich, and many others have been recognized with varying frequencies. Immunohistochemically, AFX is characterized by nonspecific profile with block-type expression of CD10 and aberrant p53 pattern and lack of pankeratin and other lineage-specific epithelial, mesenchymal, melanocytic and hematolymphoid markers. Sarcomatoid melanoma, spindle cell carcinoma and cutaneous anaplastic large cell lymphoma are major considerations. Distinction of AFX from pleomorphic dermal sarcoma (PDS) is arbitrary and is based on presence of ≥ 1 of four unfavorable histological features: more than minimal subcutaneous involvement, coagulative necrosis, lymphovascular invasion and perineurial invasion.

Peritoneal sarcomatosis due to undifferentiated pleomorphic sarcoma: A case report and review of the literature.

Undifferentiated pleomorphic sarcoma (UPS), which was previously known as malignant fibrous histiocytoma (MFH), rarely presents in the abdomen, and sarcomatosis due to UPS has not yet been reported in the literature. Here, we present a 62-year-old man who had abdominal sarcomatosis due to UPS with a poor prognosis.

Atypical fibroxanthoma and pleomorphic dermal sarcoma - gene expression analysis compared with undifferentiated cutaneous squamous cell carcinoma.

BACKGROUND: The histogenetic origin of atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) has not been definitively elucidated. In addition to a fibroblastic origin, a keratinocytic differentiation is discussed due to strong clinical, histomorphological and molecular genetic similarities with undifferentiated cutaneous squamous cell carcinoma (cSCC). PATIENTS AND METHODS: 56 cases (36 AFXs, 8 PDSs, 12 undifferentiated cSCCs) were evaluated for their clinical, histomorphological, and immunohistochemical characteristics. RNA transcriptome analysis was performed on 18 cases (6 AFXs/PDSs, 6 undifferentiated cSCCs, 6 differentiated cSCCs). RESULTS: Clinically, the strong similarities in age, gender and tumor location were confirmed. Without further immunohistochemical staining, histomorphological differentiation between AFX/PDS and undifferentiated cSCC is often impossible. Principal component analysis of the RNA transcriptome analysis showed that AFX/PDS and differentiated cSCC each formed their own cluster, while the undifferentiated cSCCs fall in between these two groups, but without forming a cluster of their own. When examining differentially expressed genes (DEGs), the heat maps showed that there were cases within the undifferentiated cSCC that were more likely to be AFX/PDS than differentiated cSCC based on their expression profile. CONCLUSIONS: The results provide evidence of molecular similarities between AFX/PDS and undifferentiated cSCC and suggest a common histogenetic origin.

Pulmonary artery angiomatoid fibrous histiocytoma mimicking pulmonary embolism.

A young man presented to the emergency department with pleuritic chest pain and shortness of breath. Of note, he recently went on a long-distance flight of about 9 hours. Given his recent long-distance travel and clinical symptoms, a pulmonary embolism was suspected. However, pathological examination of the excised pulmonary artery intraluminal mass demonstrated an angiomatoid fibrous histiocytoma. This case describes the clinicopathological and immunohistochemical features and molecular profile of a rare type of pulmonary artery tumour, a pulmonary artery angiomatoid fibrous histiocytoma.

A League of Its Own? Established and Emerging Therapies in Undifferentiated Pleomorphic Sarcoma.

OPINION STATEMENT: Over the last decade in soft tissue sarcoma (STS) research, the shifting landscape towards more precise subtype classification and the increasing study of novel therapeutic strategies has prompted a need to highlight current knowledge of effective subtype specific therapies. Undifferentiated pleomorphic sarcoma (UPS), formerly known as malignant fibrous histiocytoma (MFH), is among the most common subtypes of STS arising in the trunk or extremities of adults. Administration of systemic chemotherapy is the primary management in locally advanced and metastatic UPS. While anthracycline-based chemotherapy continues to be standard of care in this setting, outcomes in locally advanced or metastatic UPS remain poor. Recent studies highlight the unique characteristics of UPS that may contribute to its greater sensitivity to immune checkpoint inhibition (ICI) compared to other STS subtypes. With the promise of benefit from novel therapies, including ICI or ICI plus chemotherapy, for a subset of patients with UPS comes the need to identify biomarkers predictive of response to therapy. Ongoing and future clinical trials should place strong emphasis on correlative biomarker studies to learn more about the unique biology of UPS and to identify patients for whom ICI-based therapy will be effective.

Immunohistochemical Characteristics of Atypical Fibroxanthoma and Pleomorphic Dermal Sarcoma: A Systematic Review and Meta-Analysis.

BACKGROUND: Differentiating atypical fibroxanthoma (AFX) from pleomorphic dermal sarcoma (PDS) remains a challenge. Increasing the use of immunohistochemistry has led to the proposal of many immunomarkers that may aid in the diagnosis of AFX and PDS. In this meta-analysis, we investigate the immunohistochemical characteristics of AFX and PDS based on suggested immunomarkers in the literature. Second, we identify potential distinctive markers found in the tumors' respective immunohistochemical profiles. METHODS: We included studies using immunomarkers on at least 10 consecutive patients with clinically and histopathologically verified AFX or PDS. The positive rates of the immunomarkers were pooled across the included studies with random-effects models. The immunomarkers were further categorized by a priori-chosen cutoffs in positive rates as positive markers (>90%) or negative markers (<10%). Differences between AFX and PDS were compared with Wald tests. RESULTS: We included 45 studies (1516 tumors) reporting on 35 immunomarkers. CD10 was positive in 94% (95% confidence interval, 87-99) of AFX cases and 100% (95% confidence interval, 99-100) of PDS cases. In accordance with the literature, both AFX and PDS were mainly negative for epithelial markers, melanocytic markers, markers of smooth muscle differentiation, and endothelial markers. None of the examined immunomarkers could distinguish AFX from PDS. CONCLUSIONS: Our results suggest that CD10 is a useful positive immunomarker for both AFX and PDS. We found no difference in immunohistochemical profile when comparing AFX with PDS. Our analysis suggests that CD10, AE1/AE3, CK5/CK6, p63, S100, SOX10, desmin, SMA, CD31, and ERG could be used to differentiate AFX and PDS from other spindle cell neoplasms.

Increase of atypical fibroxanthoma and pleomorphic dermal sarcoma: a retrospective analysis of four German skin cancer centers.

BACKGROUND AND OBJECTIVES: In recent years, considerable insight has been gained into the pathogenesis, diagnosis and treatment of cutaneous sarcomas, including atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS). Both entities have shown increasing incidence rates in the last decade. This study was initiated to evaluate how these new insights impact the number of diagnoses of AFX/PDS compared to other cutaneous sarcoma entities. PATIENTS AND METHODS: In a retrospective study of four German skin cancer centers, all histopathological reports of cutaneous sarcomas (AFX, PDS, dermatofibrosarcoma protuberans, cutaneous leiomyosarcoma, angiosarcoma, and Kaposi sarcoma) confirmed by board-certified dermatopathologists were analyzed during a time-period of seven years (2013-2019). Additionally, utilization of immunohistochemical markers (including pan-cytokeratin, S100, desmin, CD34, CD10, procollagen-1, CD99, CD14, and CD68) as an adjunct to diagnose AFX/PDS was recorded. RESULTS: Overall, 255 cutaneous sarcomas were included in the present study. The diagnosis of a cutaneous sarcoma has consequently risen from 2013 to 2019 (from 16 to 52 annual cases). The results of AFX/PDS revealed 4.6 times more diagnoses in 2019 than in 2013. Atypical fibroxanthoma represented the most common subtype, displaying 49.3 % of all diagnosed cutaneous sarcomas. Additionally, the increase of AFX/PDS was linked to the use of immunohistochemistry, with specific immunohistochemical markers used in 57.1 % of cases in 2013 compared to 100 % in 2019. CONCLUSIONS: This retrospective study of four German skin cancer centers demonstrates a substantial rise of AFX/PDS, possibly due to recently established diagnostic and terminology standards. This rise is probably linked to increased utilization of specific immunohistochemical markers. Atypical fibroxanthoma/PDS may be more common than previously thought and seems to represent the most frequent cutaneous sarcoma subtype.

Angiomatoid fibrous histiocytoma: Report of two cases, initially construed as sarcoma with unusual clinico-pathological features.

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor of uncertain differentiation with low metastatic potential, most commonly occurring in children, adolescents, and young adults, involving extremities. Due to its rare nature and diverse presentation, both clinically and morphologically, it is often misdiagnosed. It becomes important to correctly diagnose this lesion, given its distinct therapeutic implications. Here, we present the clinical, radiologic, and pathologic findings of two rare cases of AFH. Since AFH is a rare soft tissue tumor with low malignant potential, both pathologists and clinicians should be aware of this entity, when encountered with a soft tissue mass in extremities of a child or adolescent, so as to accord appropriate treatment in such cases.

Myxofibrosarcoma: Another mimicker of meningioma / Mixofibrosarcoma: otro imitador del meningioma

Primary intracranial malignant fibrous histiocytoma (MFH), or myxofibrosarcoma, is an extremely rare condition, with only a few cases reported in the literature. We report a case of a dural-based myxofibrosarcoma in a previously healthy 42-year-old man that was initially presumed to be an atypical meningioma. The findings based on conventional and advanced magnetic resonance sequences, including diffusion-weighted imaging, perfusion weighted imaging and proton magnetic resonance spectroscopy, as well as histopathological aspects, are discussed (AU)

El histiocitoma fibroso maligno intracraneal primario (HFM) o mixofibrosarcoma, es una condición extremadamente rara, con solo unos pocos casos reportados en la literatura. Presentamos un caso de mixofibrosarcoma de base dural en un varón de 42 años, previamente sano, que inicialmente se presumió que era un meningioma atípico. Se discuten los hallazgos basados en secuencias de resonancia magnética convencionales y avanzadas, que incluyen imágenes ponderadas por difusión, imágenes ponderadas por perfusión y espectroscopía de resonancia magnética de protones, así como aspectos histopatológicos (AU)

Surgical management of primary undifferentiated pleomorphic sarcoma of the rectum: a case report and review of the literature.

BACKGROUND: Undifferentiated pleomorphic sarcoma (UPS) is a malignant soft tissue tumor that has been reclassified from malignant fibrous histiocytoma with the development of the pathological diagnosis. It principally occurs in the extremities but rarely occurs in the rectum. We herein report a rare case of UPS arising in the rectum. CASE PRESENTATION: A 85-year-old woman was referred to our hospital with a complaint of anal pain, which had persisted for several months. Computed tomography (CT) showed a 53 × 58 × 75 mm mass on the left side of the rectum. Colonoscopy revealed a submucosal elevation in the rectum without any exposure of the tumor to the surface. Contrast-enhanced CT and magnetic resonance imaging revealed an 80-mm mass that originated in the rectal muscular propria, and we suspected a gastrointestinal stromal tumor. No lymph node metastasis or distant metastasis was observed. We performed a laparoscopic Hartmann's operation. Intraoperatively, severe adhesion around the tumor caused tumor injury and right ureteral dissection. Thus, laparoscopic right ureteral anastomosis and ureteral stenting were additionally performed. The operation time was 6 h and 3 min, and the estimated blood loss was small. The patient was discharged without complications 25 days after surgery. A pathological examination showed that the tumor was composed of highly heterogeneous cells with no specific differentiation traits, leading to a diagnosis of UPS. Contrast-enhanced CT performed 2 months after surgery showed bilateral pelvic lymph node enlargement, which indicated recurrence. Considering the patient's age, we performed radiotherapy (50 Gy/25 Fr targeting the pelvic region). At present, 16 months have passed since the completion of radiotherapy. Contrast-enhanced CT shows that the recurrent lymph nodes have disappeared, and no new distant metastasis has been observed. CONCLUSIONS: We reported a case of UPS arising in the rectum. The surgical procedure and indication of preoperative therapy should be carefully selected because complete removal of the tumor is desirable in UPS.

A case of pseudomyogenic hemangioendothelioma misdiagnosed as low-grade malignant fibrous histiocytoma and review of literature. / è¯¯è¯Šä¸ºä½Žåº¦æ¶æ€§çº¤ç»´ç»„ç»‡ç»†èƒžç˜¤çš„å‡è‚Œæºæ€§è¡€ç®¡å† çš®ç˜¤1ä¾‹å¹¶æ–‡çŒ®å¤ä¹ .

Pseudomyogenic hemangioendothelioma (PHE) is a rare angiogenic tumor. Histologically, the morphological characteristics of neoplastic vessels and endothelial differentiation are not obvious, and it is easy to be confused with epithelioid sarcoma, epithelioid hemangioendothelioma and myogenic tumor. PHE usually occurs in arms and legs in young people and has a significant male predominance. The tumor has a predilection for the distal extremities and its typical manifestation is multiple center invasion of a single limb, which can involve all layers of skin and subcutaneous tissues,and is often accompanied by abvious pain. Histologically, PHE is characterized by infiltrative growth of tumor. Most tumor lesions are composed of sheets and loose fascicles of plump spindle or epithelioid cells within a background of variably prominent inflammatory infiltration, which was commonly composed of neutrophils. Some cells may resemble rhabdomyoblasts, and nuclear atypia and mitosis were rare. The tumor cells generally expressed positive cytokeratin (CK), ETS-related gene (ERG), Friend leukemia virus integration 1 (FLI1) and integrase interactor 1(INI1). In some cases, the tumor cells expressed CD31. A case of a young woman was reported in this paper, who presented with a subcutaneous mass with severe pain and was chronologically misdiagnosed with herpes zoster, low-grade malignant fibrous histiocytoma and epithelioid hemangioendothelioma. In this study, the clinical and pathological features, differential diagnosis and the latest progress in therapy of PHE were analyzed based on relevant literature.

Endobronchial Primary Pulmonary Angiomatoid Fibrous Histiocytoma in a Patient with Testicular Germ Cell Tumor: An Evidence Against Somatic Transformation.

Primary Pulmonary Angiomatoid Fibrous Histiocytoma is a recently described soft tissue tumor with challenging differential diagnosis both clinically and pathologically due to its rarity in this location. It may also occur as a secondary malignancy and its occurrence either as a somatic malignancy arising in the germ cell tumor or as a secondary malignancy after chemotherapy is questionable. In this report, we present a 29-year-old male patient with a mass in the lower lobe of the left lung, who underwent orchiectomy and received adjuvant chemotherapy due to a mixed germ cell tumor 8 years ago. Morphology, immunophenotype, and molecular findings were consistent with the diagnosis of primary pulmonary angiomatoid fibrous histiocytoma. Fluorescent in situ hybridization was unable to demonstrate the presence of 12p amplification or isochromosome 12p, which is known as the key event in the development of testicular germ cell neoplasia even present in somatic malignancies arising in germ cell tumors. Our results support that angiomatoid fibrous histiocytoma arising as a secondary malignancy does not represent the somatic transformation of germ cell tumors.

Undifferentiated pleomorphic sarcoma of the pancreas: a rare case report and literature review.

BACKGROUND: Primary undifferentiated pleomorphic sarcoma (UPS) of the pancreas is an exceedingly rare malignant tumor, with only 15 cases have been reported in the medical literature. At present, clinicians have poor recognition of the tumor, the epidemiology, diagnosis, and treatment of this disease have yet not been established. CASE PRESENTATION: In this report, we depict the clinical and imaging characteristics of a 37-year-old man presenting with a primarily cystic UPS. The patient complained of epigastric pain and distention over 20 days. Abdominal CT and pancreatic magnetic resonance imaging revealed cystic and cystic solid masses in the pancreatic body and tail. An abdominal ultrasound echogram revealed the mass in the body of the pancreas to be cystic with separation echo inside, and the wall was thick, not smooth. Besides, a hypoechoic mass was seen in the tail area of the pancreas with an inhomogeneous echoic pattern, containing small patches of no echo zone in the central. Microscopically, spindle fibroblast-like cells are arranged in a characteristic storiform pattern with pleomorphic and multinucleated cells. Immunohistochemically, tumor cells were positive for CD68 and vimentin. Seven months postoperatively, he was diagnosed with pulmonary lymph node metastasis and died 5 months later. Combined with this case report, we also reviewed the literature regarding UPS of the pancreas. CONCLUSIONS: As we know, this is the first report on ultrasonography findings of pancreatic UPS. Despite there are no distinctive manifestation of UPS, a solid cystic lesion on ultrasonography or a hypodense area in the lesion on T2-weighted imaging, should be considered for differential diagnosis with pancreatic UPS. We believe this article may add some ideas into the diagnosis and therapy of patients with this tumor.

Angiomatoid Fibrous Histiocytoma Mimicking a Lymph Nodal Lesion: A Case Report.

Angiomatoid fibrous histiocytoma is an uncommon soft tissue neoplasm with potential for recurrence and rare metastasis. The majority of cases are painless, slow growing and occur in superficial extremities of young adults. Here we report a case of Angiomatoid fibrous histiocytoma in a 28-year-old male patient presenting as a slowly growing painful mass in the groin region. This case is of particular interest due to its uncommon site of presentation and its misdiagnosis as lymph nodal lesion on radiology. Although it is a rare entity, it should be considered in differential diagnosis of soft tissue mass in a young patient.

Paraneoplastic syndrome due to angiomatoid fibrous histiocytoma: a known presentation of an uncommon diagnosis in a rare site and age.

A woman in her 70s presented with a small subcutaneous retrosacrococcygeal mass and a history of elevated erythrocyte sedimentation rate present for several years. It was misdiagnosed as an inflammatory process of unclear origin. She underwent further investigation with the appearance of weight loss and weakness. A sacrococcygeal mass was noted on CT scan. A core needle biopsy was inconclusive for chordoma versus myoepithelioma. Wide surgical resection of the tumour including the coccygeal bone was performed. Following surgery, all the systemic symptoms resolved with normalisation of inflammatory markers. The pathological examination showed a relatively circumscribed multinodular myxoid tumour with lymphatic tissue cuff. Pan-sarcoma fusion analysis detected an EWSR1 (Exon7)-CREB1 (Exon7) fusion gene. The lesion was diagnosed as angiomatoid fibrous histiocytoma with paraneoplastic syndrome presentation of several years' duration.

Pleomorphic sarcoma of maxillary sinus: Clinical report of a patient initially diagnosed with denture-induced fibrous hyperplasia.

Undifferentiated pleomorphic sarcoma is a high-grade soft-tissue malignant tumor that is rare in the head and neck region. A 74-year-old woman displayed a large nodular lesion in the maxillary alveolar mucosa, which was initially identified as denture-related fibrous hyperplasia. Although her prosthodontist has adjusted the maxillary complete denture to relieve pressure on the lesion, it increased in size over time. Computed tomography images of the maxillary sinus showed an extensive destructive lesion. A biopsy was performed, and microscopic examination revealed a poorly differentiated malignancy with numerous spindle cells. Immunohistochemistry reactions were negative for CD45, CD30, CD68, CD34, cytokeratin, S100, desmin, and smooth muscle actin. These findings led to the diagnosis of an undifferentiated pleomorphic sarcoma of the maxillary sinus.

Malignant fibrous histiocytoma of the floor of mouth: a case report and review of the literature.

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma in late adulthood and usually occurs in the limbs, trunk, and peritoneum. Less than 10% of MFH cases occur in the head and neck region. The clinical manifestations and pathological features of MFH are atypical, and it is difficult to make a clinical diagnosis. We describe a rare case of MFH of the floor of mouth and provide our diagnosis and treatment experiences. Through this review, we also evaluate the origin, World Health Organization (WHO) classification, clinical presentations, pathological features, treatment methods, and prognosis of MFH. MFH may originate from fibroblasts or primitive mesenchymal cells. MFH was defined as undifferentiated pleomorphic sarcoma in the 2002 WHO classification of bone and soft tissue tumors. The most common manifestation of MFH is a painless enlarging nodule, often without overlying epidermal ulcers. Jaw lesions are usually found after displays of swelling, pain, paresthesia, and loose teeth. MFH is composed of pleomorphic spindle cells, usually with hemorrhage, necrosis, and lymphocyte infiltration. The main treatment method is surgical resection. Moreover, radiotherapy and chemotherapy have certain auxiliary effects. The local recurrence and distant metastasis of MFH are common, and the prognosis is poor. Therefore, determining the histopathological features of MFH and conducting appropriate immunohistochemical examinations are crucial in establishing the correct diagnosis. In-depth study is required in order to have a better understanding of head and neck MFH.