EWSR1-SMAD3 rearranged fibroblastic tumor: Case series and review.

We report the largest series to date (N = 6) of EWSR1-SMAD3 rearranged fibroblastic tumor. Initially described in 2018, the tumor features a marked female predominance (F:M, 5:1, mean age 44-years, median age 45.5 years; range 27-57), with most cases (5/6, 83%) arising in acral locations (4 on foot/toe, 1 on hand). One case presented on the lower extremity. The lesions presented as nodules and were composed of short, variably cellular, intersecting fascicles of uniform spindled cells in a collagenous to myxoid stroma. In four cases, the tumor abutted the epidermis without a grenz zone. In one case, there was an abrupt transition to a central, acellular hyalinized area. Two other cases had admixed smaller collagenous areas, reminiscent of collagen rosettes. One had a concentric arrangement of tumor cells around blood vessels. Mitotic activity was low (<1/10 HPFs). All were positive for ERG by immunohistochemistry and negative for CD34 (6/6). An EWSR1-SMAD3 fusion was identified in three cases tested by next-generation sequencing (3/3). Rearrangement of EWSR1 by fluorescence in situ hybridization was showed in 1/1 case. Our series reaffirms prior findings and expands the known histopathologic spectrum of this emerging entity.

Cutaneous pleomorphic fibromas arising in patients with germline TP53 mutations.

Pleomorphic fibromas are rare benign cutaneous neoplasms associated with deletion/loss of chromosomes 13q and 17p, where RB1 and TP53 are located, respectively. Herein, we report five cases of pleomorphic fibroma arising in patients with germline TP53 mutations, suggesting a potential link with Li-Fraumeni syndrome. All three patients were female and young (mean age 27) with a strong personal and/or family oncologic history and confirmed pathogenic germline TP53 mutations. In two patients, multiple pleomorphic fibromas were diagnosed. Clinically, the lesions arose at various cutaneous sites and were small (≤2 cm) and raised (4/5). Histopathologically, the tumors were paucicellular, composed of atypical spindled to stellate cells with hyperchromatic and variably pleomorphic nuclei. Mitotic activity was exceedingly low, although rare atypical mitotic figures were seen in one case. Immunohistochemically, the tumor cells were diffusely positive for p16 (3/3) and showed loss of Rb expression (5/5). All cases showed aberrant p53 expression (overexpression in 4, complete loss in 1). The tumors have followed a benign clinical course with no evidence of progression or recurrence. In conclusion, the development of multiple pleomorphic fibromas in a young patient may be a clue to an underlying genetic cancer syndrome involving TP53.

Clinicopathologic Study of Calcifying Fibrous Tumor Emphasizing Different Anatomical Distribution and Favorable Prognosis.

AIMS: Calcifying fibrous tumor (CFT) is a very rare begin fibroblastic tumor featuring a widely anatomical distribution and may mimic various spindle cell tumors. Misdiagnosis and hence mistreatment are likely caused due to unfamiliarity to clinicians or junior pathologists. We collected a relatively large series of CFTs in our institution aiming at further summarizing their clinicopathologic features in Chinese patients and discussing the diagnosis and differential diagnosis in clinical practice. METHODS: Clinicopathologic data of 22 CFTs were retrospectively reviewed. Histologic features were reevaluated and summarized. Immunostaining markers include CD34, SMA, Desmin, keratin, S100, ALK1, CD117, IgG, IgG4, and Ki-67. Follow-up of all cases was performed. RESULTS: 22 CFTs include gastric (n=8), pulmonary (n=2), hepatic (n=2), cervical (n=1), appendiceal (n=1), esophageal (n=1), retroperitoneal (n=1), intra-abdominal (n=1), diaphragmatic (n=1), spermatic cord and scrotum (n=1), anconeal (n=1), mesenteric (n=1), and omental (n=1) lesions. Coexisting hepatocellular carcinoma, pancreatic carcinoma, pheochromocytoma, Castleman disease, and leiomyoma of the uterus and other metabolic or functional disorders were also appreciated. CFT histologically features spindle cells embedded dense hyalinized stroma with scattered psammomatous calcifications and lymphoplasmacytic infiltration and immunohistochemically for CD34. None of any individuals die of CFT per se. CONCLUSION: Our study discloses that CFT is a bona fide benign fibroblastic lesion, regardless of its developing location. Involvement of digestive tract seems much more common in the Chinese population. Awareness of the clinicopathologic characteristics of this rare entity and its mimickers contribute to avoiding misdiagnosis and mistreatment in clinical practice.

Superficial CD34 positive fibroblastic tumor: report of three cases and review of the literature.

Superficial CD34 positive fibroblastic tumor (SCPFT) is a recently recognized, unique neoplasm with distinctive histomorphological features such as high pleomorphism, low mitotic rate, and diffuse CD34 reactivity. Hereby we present three cases of our experience with clinicopathological, morphological, and immunohistochemical characteristics. The patients were a 31-year-old female, 53-year-old female, and 33-year-old male. The tumors were all superficially located; left forearm, medial aspect of the left ankle, and left thigh, respectively. Histomorphologically they had expansile and focal infiltrative growth pattern consisting of highly pleomorphic spindle cells with intranuclear inclusions, yet low mitotic rate. Tumoral cells showed strong and diffuse reactivity for CD34. One of our cases showed focal and weak reactivity for pancytokeratin. Unlike the other two tumors, one case was positive for desmin. During the clinical follow-up, one case showed local recurrence four times. SCPFT is a newly recognized, borderline mesenchymal neoplasm of soft tissues that can show local recurrence or even rarely metastasize. To the best of our knowledge, this three case series is the first to be reported from Turkey. Our aim to report these three cases was to make contribution to the literature about this rare entity and increase awareness.

Paratesticular Fibrous Pseudotumor: A New Entity of IgG4-Related Disease?

INTRODUCTION: Paratesticular fibrous pseudotumor (PFP) represents a benign tumor-like lesion confined to intrascrotal, paratesticular areas. Due to its rarity, only less than 200 cases have been reported to date, of which both pathogenesis and clinical management are little understood. Recently, PFP has been postulated to be among the spectrum of so-called immunoglobulin G4-related diseases (IgG4-RD). Here we describe a case of PFP focusing on the clinical, morphological features and the utility of immunohistochemistry to support the theory that PFP might be a potential member of IgG4-RD family. CASE PRESENTATION: A 41-year-old man presented with a slowly growing, right intrascrotal mass An MRI scan revealed a diffuse-proliferative nodular mass around the paratesticular area. The patient underwent right orchiectomy and a diffuse multinodular tumor with testicular compression was discovered without intratesticular infiltration. Postoperatively, the patient has been well for 2 years up to the recent follow up. On histological examination, the lesion consisted of hyalinized fibrotic tissue with storiform patterns. There were scattered germinal centers; lymphocytic vasculitis was also noted. The immunoglobulin G4 staining showed infiltration of positive plasma cells with highest count 52 per high-power field, whereas the mixed Kappa and Lambda immunoglobulin light chain expression indicated the polyclonality of the plasma cell population. CONCLUSIONS: The morphological and immunohistochemical features in our case support the theory of PFP being part of IgG4-RD. Familiarity to this tumor-like lesion is crucial, since it may respond to corticosteroid therapy, which may save patients from more aggressive surgical procedures.

Superficial CD34-positive fibroblastic tumor: Cytologic features, tissue correlation, ancillary studies, and differential diagnosis of a recently described soft tissue neoplasm.

Superficial CD34-positive fibroblastic tumor is a low-grade mesenchymal neoplasm of superficial soft tissues characterized by fascicles of spindle to epithelioid cells displaying nuclear pleomorphism and strong diffuse CD34 immunoreactivity. The intraoperative imprint cytology preparations (ICP) of a superficial CD34-positive fibroblastic tumor from a 50-year-old female are described. To the best of our knowledge, there is no report of the cytologic findings of superficial CD34-positive fibroblastic tumor in the English medical literature. The ICP, differential diagnosis, tissue correlation, and ancillary studies of this fascinating entity are discussed. Diagn. Cytopathol. 2016;44:926-930. © 2016 Wiley Periodicals, Inc.

[Value of MDM2, CDK4 and SATB2 immunohistochemistry in histologic diagnosis of low-grade osteosarcoma].

OBJECTIVE: To investigate the value of combined application of MDM2, CDK4 and SATB2 immunohistochemistry in pathological diagnosis of low-grade osteosarcoma. METHODS: Forty-seven cases of low grade osteosarcoma, including low grade central osteosarcoma (n=20) and parosteal osteosarcoma (n=27), were selected from Shanghai Jiaotong University Affiliated the Sixth People's Hospital. The clinical, radiography and histopathology were reviewed. The sensitivity and specificity of MDM2, CDK4 and SATB2 immunohistochemistry in the diagnosis of low-grade osteosarcoma were assessed along with an evaluation of their expressions in fibrous dysplasia, desmoplastic fibroma, low-grade fibrosarcoma and other fibrous tumors. RESULTS: Low-grade osteosarcoma had protracted clinical course, occurring mostly in elder adults and mainly involving long bones. Radiographic studies showed that low-grade central osteosarcoma had a mainly malignant lytic presentation, however about 5/18 of tumors overlapping with intermediate and benign bone diseases, while parosteal osteosarcoma was characterized by a densely sclerotic malignant appearance. Histologically, low-grade osteosarcomas were characterized by well-differentiated spindle tumor cells, various mature tumor bones and an aggressive growth pattern. The positive expression rates of MDM2 and CDK4 in low-grade osteosarcoma were 74.5% and 55.3%, respectively. Eighty-three percent of low-grade osteosarcoma expressed one or both markers. Low-grade osteosarcoma and fibrous dysplasia were both positive for SATB2, while desmoplastic fibroma, low-grade fibrosacoma and other fibrous tumors were negative for SATB2. CONCLUSIONS: Accurate diagnosis of low-grade osteosarcoma should be based on combination of clinical presentation, imaging and histopathology, with immunohistochemistry as a diagnostic adjunct. Positive immunostaining for CDK4 and/or MDM2 supports the diagnosis of low-grade osteosarcoma, but the negative one does not rule out such lesion. The negative expression of SATB2 is helpful to exclude fibrous tumors originating from bone with the exception of fibrous dysplasia.

IMP3 and GLUT-1 immunohistochemistry for distinguishing benign from malignant mesothelial proliferations.

Distinguishing malignant mesotheliomas from benign mesothelial proliferations on hematoxylin and eosin-stained sections can be extremely challenging. Various immunohistochemical stains have been suggested to help in making this distinction, but all are controversial. Recently, IMP3 (insulin-like growth factor II mRNA binding protein 3) and GLUT-1 (glucose transporter protein 1) have been proposed as immunohistochemical markers that are positive in mesotheliomas but not in benign proliferations. We evaluated the performance of these markers on a tissue microarray containing 30 malignant mesotheliomas and 48 benign thoracic or abdominal mesothelial proliferations. IMP3 was positive in 53% of malignant and 27% of benign cases (P=0.03), whereas GLUT-1 was positive in 60% of malignant and 13% of benign cases (P=0.0003). Forty-three percent of malignant cases, but only 4% of benign cases, were positive for both IMP3 and GLUT-1 (P=0.00003). We conclude that, statistically, both IMP3 and GLUT-1 are more frequently positive in malignant compared with benign mesothelial processes; however, the frequency of positive staining in benign cases is too high to allow their diagnostic use as single stains. The combination of both markers may be of greater diagnostic value, but this hypothesis should be confirmed in further studies.

Vasculogenic mimicry of HT1080 tumour cells in vivo: critical role of HIF-1α-neuropilin-1 axis.

HT1080 - a human fibrosarcoma-derived cell line - forms aggressive angiogenic tumours in immuno-compromised mice. In spite of its extensive use as a model of tumour angiogenesis, the molecular event(s) initiating the angiogenic program in these cells are not known. Since hypoxia stimulates tumour angiogenesis, we examined the hypoxia-induced events evoked in these cells. In contrast to cells grown under normoxic conditions, hypoxia-primed (1% O(2)) HT1080 cells formed robust tubules on growth factor-reduced matrigel and formed significantly larger tumours in xenograft models in a chetomin-sensitive manner, indicating the role of HIF-1α-mediated transcription in these processes. Immuno-histochemical analyses of tumours formed by GFP-expressing HT1080 cells clearly showed that the tumour cells themselves expressed various angiogenic markers including Neuropilin-1 (NRP-1) and formed functional vessels containing red blood cells, thereby unambiguously demonstrating the vasculogenic mimicry of HT1080 cells in vivo. Experiments performed with the HT1080 cells stably transfected with plasmid constructs expressing shNRP-1 or full-length NRP-1 clearly established that the HIF1α-mediated up-regulation of NRP-1 played a deterministic role in the process. Hypoxia-exposure resulted in an up-regulation of c-Myc and OCT3/4 and a down-regulation of KLF4 mRNAs, suggesting their involvement in the tumour formation and angiogenesis. However, silencing of NRP-1 alone, though not affecting proliferation in culture, was sufficient to abrogate the tumour formation completely; clearly establishing that the hypoxia-mediated HIF-1α-dependent up-regulation of NRP-1 is a critical molecular event involved in the vasculogenic mimicry and tumor formation by HT1080 cells in vivo.

Cutaneous clear cell neoplasms: a histopathological reappraisal.

Cutaneous clear cell neoplasms represent a heterogenous group of several primary and metastatic tumors with diverse histogenesis. Tumors with widespread clear cell change can seem strikingly similar under the microscope resulting in diagnostic difficulties. Although most cases are idiopathic, intracytoplasmic accumulation, artifact of tissue processing, and degenerative phenomenon have been cited as possible causes of clear cell change. An awareness of the various entities demonstrating this attribute, judicious use of ancillary techniques, and knowledge of the clinical setting are crucial to the accurate diagnosis. This review details the histological features of clear cell neoplasms of the skin with particular emphasis on the discriminating features.

Fibrous stroma is associated with poorer prognosis in lung squamous cell carcinoma patients.

INTRODUCTION: Cancer tissue is composed of various stromal cells forming cancer-specific microenvironments. Peritumoral stroma is reportedly composed of activated fibroblasts that can influence the biological properties of tumor cells, mainly their local aggressiveness and their ability. The aim of this study was to examine whether the histological properties of peritumoral stroma are correlated with squamous cell carcinoma (SqCC) aggressiveness and clinical outcome. METHODS: A series of 220 pathological stage I lung SqCC were categorized into two types according to the histological properties of the peritumoral stroma, "fibrous stroma type" (n = 85), and "thin stroma type" (n = 135), and compared the prognostic significance. Furthermore, we compared the immunohistochemical properties of the SqCC cells surrounded by "fibrous stroma" with those of the SqCC cells surrounded by "thin stroma." RESULTS: The prognosis of the patients with fibrous stroma-type tumors was significantly poorer than that of the thin stroma type with regard to both recurrence-free survival (p = 0.005) and overall survival (p = 0.008). A multivariate analysis showed that the presence of a fibrous stroma was an independent prognostic factor (p = 0.030). Compared with the SqCC cells with a thin stroma, the SqCC cells with a fibrous stroma exhibited reduced expression of E-cadherin (55.9 versus 126.0, p < 0.001) and an increased expression of laminin-5γ2 (94.6 versus 25.0, p = 0.001), matrix metalloproteinase-7 (26.0 versus 3.50, p = 0.009), and c-Met (64.0 versus 36.5, p = 0.033). CONCLUSION: SqCC with a fibrous stroma displayed higher invasive phenotype and were associated with a significantly poor prognosis. The current results suggest that the microenvironment created by both SqCC cells and the peritumoral fibroblasts may facilitate cancer aggressiveness.

[Clinicopathologic features of calcifying fibrous tumor with reappraisal of its histogenesis].

OBJECTIVE: To study the clinicopathologic features and histogenesis of calcifying fibrous tumor (CFT). METHODS: The clinical manifestations, histopathologic characteristics and immunophenotype were analyzed in 11 cases of CFT. RESULTS: The male-to-female ratio was 5:6, with a mean age of 38 years and age range of 25 to 52 years. The sites of involvement included abdominopelvic cavity (n=6), soft tissue (n=4) and scrotum (n=1). Most patients presented with a gradually enlarging and painless mass. Nearly half of the cases were associated with other diseases or history of inflammation, trauma or surgical intervention. One third of the tumors represented incidental findings and showed no recurrence after resection. Imaging revealed a solitary solid soft tissue mass or multiple nodules with clear borders and associated high-density calcifications. Macroscopically, the tumors were well-circumscribed but non-encapsulated. They ranged from 0.5 to 20.0 cm in diameter and were tan-greyish, round to oval, lobulated or irregular and solid with rubbery consistency. The cut surface was whitish to tan-yellowish, gritty and showed scattered spotty yellowish discoloration corresponding to the foci of dystrophic calcifications. Histologically, CFT was composed of hyalinized fibrous tissue and thickened vessel walls with interspersed bland spindly fibroblastic cells, scattered psammomatous calcifications, dystrophic calcification and lymphoplasmacytic infiltration. In addition, focal cloak-like polymorph infiltration at the tumor periphery and entrapment of adipocytes and nerves were demonstrated in some cases. Foci resembling solitary fibrous tumor, fibromatosis, keloid or inflammatory myofibroblastic tumor were observed. Immunohistochemical study showed that the tumor cells were diffusely positive for vimentin and focally positive for CD34, factor VIII-related antigen and beta-catenin. The admixed plasma cells were notably IgG positive, with more than 50% being IgG4 positive. CONCLUSIONS: CFT has characteristic histopathologic manifestations and shows morphologic and immunohistochemical overlaps with known IgG4-related sclerosing diseases. It is possible that CFT may represent another example of IgG4-related diseases. It often runs a benign clinical course, with rare recurrence after surgical resection. Previous inflammation and trauma may be the precipitating factors of CFT.

Calcifying fibrous tumor of the stomach: clinicopathologic and molecular study of seven cases with literature review and reappraisal of histogenesis.

Calcifying fibrous tumor (CFT) is a rare benign mesenchymal tumor composed of hyalinized fibrous tissue with interspersed bland fibroblastic spindled cells, scattered psammomatous, and/or dystrophic calcifications and variably prominent mononuclear inflammatory infiltrate. CFTs show a predilection for the abdominal cavity and soft tissue. To date, 6 gastric and 3 intestinal CFTs have been reported. We analyzed 7 gastric CFTs including 6 new cases. Patients were 4 men and 3 women with a mean age of 53 years (range, 40 to 77). Mean tumor size was 2.2 cm. Most tumors originated in the gastric body (6/7). Six were incidental findings at autopsy or during surgery for other diseases. One ulcerated tumor caused iron deficiency anemia and ulcer symptoms. Six tumors involved the muscularis propria with variable submucosal and subserosal extension and 1 arose within thickened muscularis mucosae adjacent to a mucosal invagination. Histology was typical with uniformly hypocellular vaguely storiform collagen, lymphoplasmacytic infiltrates, lymphoid aggregates and psammomatous, and dystrophic calcifications. Peritumoral lymphoid aggregates were seen in 3 cases. Adjacent muscle coat contained lymphoid aggregates with fiber degeneration (2), minute CFT-like foci (1), and calcifications (1). In none of the cases were there remnants of burnt-out GIST, inflammatory fibroid polyp, inflammatory myofibroblastic tumor, leiomyoma, schwannoma, or other specific lesion. All tumors were negative for CD117, S100, smooth muscle actin, desmin, ALK1, h-caldesmon, and PDGFRA. Two stained focally with CD34. Scattered IgG4-positive plasma cells were seen in 4 of 6 cases stained with this marker. All 5 tumors with available tissue for molecular analysis were wild-type for KIT and PDGFRA. Three patients had follow-up (range, 12 to 24 mo); none developed recurrence. Gastric CFTs are distinct from sclerosing GIST and other mesenchymal gut lesions and may represent a localized inflammatory fibrosclerosis in response to immune-mediated or other-type tissue injury affecting the muscularis propria. They differ from soft tissue CFTs by smaller size, older age at presentation and lack of recurrence, and from peritoneal CFTs by equal gender distribution, older age, and absent multifocal occurrence.

[Fibrolamellar carcinoma of the liver].

The paper presents the data available in the literature and theauthors' own case of hepatic fibrolamellar carcinoma developing in a 49-year-old male patient. A complex morphological (histological and immunohistochemical) study has shown that the tumor is presented by trabecular, alveolar, and glandular structures separated by connective tissue interlayers. The tumor cells showed a positive reaction with cytokeratins 7, 8,18, 19, vimentin, synaptophysin, alpha-fetoprotein, carcinoembryonic antigen, and CA 19-9.

Solitary fibrous tumor of the pancreas: a case report.

Solitary fibrous tumor (SFT) is an unusual mesenchymal neoplasm that most often arises in the pleura; however, it has recently been described in a number of extrapleural sites. This report describes an extremely rare case of a benign SFT arising in the pancreas. A 41-year-old woman presented in the clinic with right upper abdominal pain. Subsequent ultrasonographic studies revealed a 1.5x1.5x1.4 cm hypoechoic mass within the pancreatic body, which was later confirmed on both helical computerized tomography and magnetic resonance imaging studies. An endocrine tumor was clinically suspected. Laparoscopic enucleation of the mass was performed. Microscopically, the tumor was composed of bland uniform spindle cells arranged between collagen bundles. On immunohistochemical studies, these spindle cells were positive for CD34 and bcl-2 but negative for cytokeratin (AE1+AE3 and Cam5.2), smooth muscle actin, desmin, S-100, and c-kit. Based on the light microscopic morphology and immunohistochemical staining profile, the diagnosis of SFT was rendered.

Solitary fibrous tumor associated with non-islet cell tumor hypoglycemia.

A 79-year-old man presented with abnormal fluttering movements of his extremities early in the morning. Fasting hypoglycemia was believed to be the cause of the movements. A computed tomographic scan showed a large mass in the left inferior hemithorax. Non-islet cell tumor hypoglycemia was suspected, and the mass was resected while the patient was under glucose supplementation therapy. The plasma glucose level became stable shortly after tumor excision. The resected tumor was diagnosed as a solitary fibrous tumor producing insulin-like growth factor II. In the follow-up examination approximately 2 years after the surgery, no recurrence of the tumor was observed, and the plasma glucose level was stable.

Comparison of sporadic sclerotic fibroma and solitary fibrous tumor in the oral cavity.

Sporadic sclerotic fibroma (SF) and solitary fibrous tumor (SFT) arising in the oral cavity are very rare. In this report, we describe two cases of oral pathology, one involving SF and the other involving SFT. Both cases presented with well- circumscribed, firm nodules with similar gross findings. However, the histologic findings of the SF and SFT showed rather distinct features. The SF was composed of hyalinized sclerotic collagen bundles arranged in a whorled pattern, whereas the SFT was formed by spindles cells arranged in hypo- and hypercellular areas. The immunohistochemical findings were similar in both cases; there was positivity for vimentin, CD34, and CD99, but bcl-2 positivity was only seen in the SFT. Although their histopathologies are similar, SF and SFT should be considered in the differential diagnosis of soft tissue tumors in the oral cavity.