Low-grade sarcomas with CD34-positive fibroblasts and low-grade myofibroblastic sarcomas

A Differential Clinical Diagnostic Challenge of a Recurrent, Oral Fibrosarcoma Resembling a Periapical Lesion of Endodontic Origin

A fibrosarcoma is a neoplastic growth originating from malignant, fibroblast-like mesenchymal cells. This malignant tumor shows an increased tendency for expansion and recurrence and a propensity to metastasize, especially to the lungs. Despite their rarity, fibrosarcomas have the potential to manifest in any anatomical location. An oncologist referred their patient due to reported mandibular discomfort, ache, and swelling. The biopsy revealed a fibrosarcoma resembling a periapical lesion of endodontic origin. The timely intervention and the collaboration among different but complementary medical and dental specialties ensure that the patient may enjoy a prolonged life expectancy as symptom-free as possible.

Small biopsies in the head and neck: Bone and soft tissue

Bone and soft tissue lesions in the head and neck encompass not only a broad morphologic spectrum but also significant inherent clinicopathologic overlap. Epidemiology, radiology, and location - similar to the diagnostic assessment in other sites - are especially important considerations in the context of an established mesenchymal proliferation. Herein, the approach towards diagnosis is stratified by morphology (spindle, sarcomatoid, epithelioid, round cell), cellular lineage (fibroblastic, nerve sheath, rhabdomyogenic), and tumor grade (benign, low- to high-grade malignant) as the basis of further immunohistochemical or molecular investigation.

The efficacy of Mohs micrographic surgery over the traditional wide local excision surgery in the cure of dermatofibrosarcoma protuberans

Usually most patients with dermatofibrosarcoma protuberans (DFSP) may present rather late when the tumor is in protuberant phase due to its rarity and indolent onset. It has a high propensity for local recurrence and destructive nature. Management of DFSP requires a biopsychosocial and Multidisplinary approach regardless of the clinical or immunohistochemical variant. Surgery is the Gold standard management of localized disease. DFSP rarely exhibits any lymphatic or hematogenous dissemination. It is because of its high recurrence rate associated with Wide Local Excision (WLE), the introduction of Mohs micrographic surgery (MMS) has really helped in reducing the rates of recurrence of DFSP. Thus, the aim of this meta-analysis and systemic review is to advocate for MMS over WLE for DFSP and other cutaneous malignancies using DFSP as a prototype. The objective of this study were to conduct a meta-analysis on comparative surgical methods used in the cure of DFSP with regards to WLE verses MMS, to evaluate the cure rates with relation to recurrence rates, offer a recommendation on the various treatment modalities based on the location of lesion, and use of adjuvant therapy in different clinical-medical setups. A comprehensive retrospective analysis search in EMBASE, Google Scholar and Medline (PubMed) for studies published from 2008 to 2018 containing the surgical management of DFSP with WLE verses MMS were reviewed. Five studies of moderate-quality evidence (level B) with a pooled patient load of 684 was analyzed and found for recurrence of DFSP after WLE and MMS to be 9.10% and 2.72% respectively after an average follow-up time for both groups of 5.32 years with a female predominance of 1.58. The trunk is the commonest site for the DFSP lesion which was at 52.80% then the upper and lower extremities zones and the head and neck zones at 31.75% and 15.45% respectively. The pooled adjusted odds ratio (OR) analysis indicated that there was a direct relationship with regards the reduced recurrence rate of DFSP in the MMS group compared to the WLE group (OR:0.31;95%; CI :0.17-0.56). Furthermore, there was significant association between the reduced recurrence rate with the MMS in DFSP patients with a statistical P-value of 0.0001 at 95% CI. The expected increased recurrence rate by zones was in WLE head and neck zone at 38.19% then trunk and extremities zone at 13.34%. In the MMS group it was at of 23.4% as compared to 16.0% in the head and neck zone. Mohs Micrographic Surgery (MMS) is more efficacious in the cure rate and recurrence reduction of DFSP and should be advocated for as first line therapy especially in high recurrence prone zones.

Discovery and mechanisms of host defense to oncogenesis: targeting the β-defensin-1 peptide as a natural tumor inhibitor

Human beta-defensin-1 (hBD-1) is one of a number of small cationic host-defense peptides. Besides its well-known broad-spectrum antimicrobial function, hBD-1 has recently been identified as a chromosome 8p tumor-suppressor gene. The role of hBD-1 in modulating the host immune response to oncogenesis, associated with cell signaling and potential therapeutic applications, has become increasingly appreciated over time. In this study, multiple approaches were used to illustrate hBD-1 anti-tumor activities. Results demonstrate that hBD-1 peptide alters human epidermal growth factor receptor 2 (HER2) signal transduction and represses retroviral-mediated transgene expression in cancer cells. Loss of orthologous murine defense-1 (mBD1) in mice enhances nickel sulfate-induced leiomyosarcoma and causes mouse kidney cells to exhibit increased susceptibility to HPV-16 E6/7-induced neoplastic transformation. Furthermore, for the first time, a novel function of the urine-derived hBD-1 peptide was discovered to suppress bladder cancer growth and this may lead to future applications in the treatment of malignancy.

Dermatofibrosarcoma protuberans: clinicopathologic presentation in Nigerians

Introduction

Dermatofibrosarcoma protuberance (DFSP) is in general a rare low grade malignant sarcoma and possesses a tendency for local recurrence. It has a site predilection for the trunk. Occurrence in the facial area is extremely rare. Ample knowledge of its clinical, histological and biologic characteristics is vital for accurate and prompt recognition.

Methods

Over 13 years, clinicohistologic information of cases was retrieved. Histological and immunohistochemical re-evaluation were performed to re-confirm diagnosis. Data collected and analyzed with SPSS Statistics version 20 were presented as frequency tables, charts and proportions as appropriate.

Results

Of 191 soft tissue sarcomas, a total of 28 cases were diagnosed as DFSP (14.7%). Facial types occurred in 3 cases (1.6%). Tumour had age and site predilections for the 4^th decade and trunk respectively. There was an equal gender distribution among cases. Most common clinical presentation was in form of painless protruding nodular mass. General histologic presentation revealed cellular lesions composed of spindle to oval neoplastic cells arranged in a storiform pattern. Mitotic figures were rare. All cases showed positive expressions to CD34.

Conclusion

Facial DFSP is rare among Nigerians. Its clinical appearance may mimic other common benign lesions of the head and neck region often resulting in misdiagnoses. A comprehensive knowledge of its clinical and histologic presentations and biologic behavior, combined with its identification with the aid of advanced histologic and radiographic techniques results in prompt confirmatory diagnosis. Appropriate treatment should include adequate surgical excision techniques combined with adjuvant radiotherapy or chemotherapy.

Update from the 4th Edition of the World Health Organization of Head and Neck Tumours: Tumours of the Oral Cavity and Mobile Tongue

There have been several additions and deletions in Chapter 4 on Tumours of the oral cavity and mobile tongue in the 2017 fourth edition of the World Health Organization Classification of Tumours of the Head and Neck. This chapter excludes the oropharynx, which now is a stand-alone chapter acknowledging the uniqueness of the oropharynx from the oral cavity. New entries in Chapter 4 include rhabdomyoma, haemangioma, schwannoma, neurofibroma and myofibroblastic sarcoma in the section titled Soft tissue and neural tumours. Discussion of salivary gland entities have been reduced and includes mucoepidermoid carcinoma and pleomorphic adenoma as the other salivary gland types are discussed elsewhere. In the Haematolymphoid tumours section, like the salivary gland section, only tumors that commonly present in the oral cavity are discussed in Chapter 4. Excluded entities in the updated classification include papillary hyperplasia, median rhomboid glossitis, keratoacanthoma, focal oral mucinosis, and secondary tumors. This article will summarize the changes in the new classification since the 2005 edition focusing on selected entities that have had significant changes along with new entries.

The Spectrum of Canine Cutaneous Perivascular Wall Tumors: Morphologic, Phenotypic and Clinical Characterization

Perivascular wall tumors (PWTs) are defined as neoplasms deriving from mural cells of blood vessels, excluding the endothelial lining. The spectrum of human cutaneous PWT includes glomus tumor, hemangiopericytoma (HEP), myopericytoma, angioleiomyoma/sarcoma, angiomyofibroblastoma, and angiofibroma. The purpose of this study was to revise clinical presentation, cytology, histopathology, and immunohistology of canine cutaneous PWT with cytology typical of canine HEP. Diagnosis was established on the basis of vascular growth patterns (staghorn, placentoid, perivascular whorling, bundles from media) and immunohistology, including 7 smooth muscle markers and the cell membrane ganglioside of unknown origin recognized by the antibody 3G5 (CMG-3G5). Twenty cases were included. Ages ranged from 6 to 13 years; 12 dogs were males and 8 were females, and there was a prevalence of crossbreeds. Tumors arose from a single site with preferential acral location (10/20). Cytology revealed moderate to high cellularity in all cases, cohesive groups of cells (19/20), capillaries (18/20), and bi- to multinucleated cells (18/20). Six myopericytomas, 5 angioleiomyomas, 2 angioleiomyosarcomas, 2 HEP, 1 angiofibroma, and 1 adventitial tumor were identified. A definitive diagnosis was not possible in 3 cases. Smoothelin, heavy caldesmon, desmin, myosin, calponin, and CMG-3G5 were the most valuable markers to differentially diagnose canine PWT. Similar to reports in humans, canine HEP embodied a spectrum of neoplastic entities arising from different vascular mural cells. Before canine PWTs are assimilated into one prognostic category, a consistent classification and characterization of their biology is necessary. As proposed in humans, HEP should also be considered a diagnosis of exclusion in dogs.

The Current Status of Solitary Fibrous Tumor: Diagnostic Features, Variants, and Genetics

Solitary fibrous tumor (SFT) is a fibroblastic mesenchymal tumor originally described in the pleura but now shown at almost every anatomic site. Histopathologically, SFT is characteristically a circumscribed neoplasm composed of variably cellular and patternless distributions of bland spindle and ovoid cells within prominent collagenous stroma and shows diffuse expression of CD34, but it has a broad spectrum of both morphology and of biologic behavior. Many different names (particularly hemangiopericytoma) were previously used in the course of our understanding of this neoplasm but are now subsumed under the term "SFT," and the putative cell of origin was debated. However, it is now recognized that SFT is a translocation-associated neoplasm, consistently associated with NAB2-STAT6 gene fusions arising from recurrent intrachromosomal rearrangements on chromosome 12q, and this translocation is a likely major contributor to its pathogenesis. While most SFT with classical morphologic features behave in an indolent manner and those with overtly malignant histologic features tend to be aggressive neoplasms that behave as high-grade sarcomas, the behavior of SFT is unpredictable, and it is important to be aware of the propensity for aggressive behavior in a minority of histologically classical SFT and to ensure adequate clinical follow-up. Surgical excision remains the treatment gold standard; while radiotherapy and conventional chemotherapeutic agents have only shown limited efficacy, further understanding of the molecular events underlying tumorigenesis may allow the development of novel targeted treatments. We review SFT, discussing the morphologic spectrum and variants, including malignant and dedifferentiated subtypes, clinicopathological aspects, recent molecular genetic findings, and the differential diagnosis.

The "myofibroblast" that is omnipresent in pathology and key to the EMT concepts does not actually exist, since normal fibroblasts contain stress fibril organelles (SMA bundles with dense bodies) variably detected by TEM and IHC: conclusions by a diagnostic pathologist with decades of ultrastructural experience

The so-called "enigmatic" unique "myofibroblast" has been erroneously substituted for virtually all things fibroblastic in soft tissue pathology and believed to be the ultimate fibrogenic cell. It is also internationally considered to be the mesenchymal cell in un-proven post-natal EMT, EMT organ/tissue fibrosis, and the assumption that EMT/MET is key to carcinoma/adenocarcinoma invasion and metastasis. However, no such cell exists, having been mistaken for our normal ubiquitous fibrogenic fibroblasts that contain peripheral bundles of actin (SMA) with dense bodies, i.e. stress fibril (SF) organelles variably detectable by TEM and SMA IHC, depending on the degree of activation. The only detectable features distinguishing what are erroneously believed to be two unique fibrogenic spindle cells are the SF. Is the variable detection of SF/SMA in fibroblastic and non-fibroblastic lesions significant? Carcinosarcomas are not bi-phasic malignancies or proof of EMT/MET. What does it mean that the fibroblasts of so-called "carcinoma-associated fibroblasts (CAF)" are not "myofibroblasts"? The true myofibroblast is the ultrastructurally and functionally unique, terminally-differentiated, pathognomonic cell of physiologic wound-healing, which unfortunately has been confused with the activated fibroblast. This study fails to demonstrate any ultrastructural evidence that either normal epithelial (EMT) or carcinoma/adenocarcinoma cells can undergo reversible transition into mesenchymal cells (EMT/MET) under any circumstances. The SF/SMA-positive fibrogenic cell in organ/tissue fibrosis is the genetically up-regulated, activated fibroblast, which has no relationship to EMT. Are any of the innumerable biochemical factors/elements considered to be associated with this non-existent cell and its related processes related to the activated fibroblast? The conclusions are based on review of every electron micrograph taken during a 40-year career in diagnostic and research ultrastructural pathology, and by confirming that the published TEM figures of so-called "myofibroblasts", are actually of fibroblasts.

Long-term disease-free survival after radical local excision of low-grade myofibroblastic sarcoma of the vulva

•A second case of low-grade myofibroblastic sarcoma of the vulva.•Six-year follow-up with no evidence of disease after radical local excision.•Adequate margin resection is important.

Surgical management of sinonasal hemangiopericytomas: a case series

BACKGROUND

Sinonasal hemangiopericytomas are rare low-grade sarcomas. The role of endoscopic management has not been adequately studied.

METHODS

This study was conducted through retrospective medical chart review of patients seen with sinonasal hemangiopericytomas at 2 institutions over a 19-year period. Demographic, clinicopathological, and surgical information was analyzed with descriptive statistics.

RESULTS

Thirteen patients with a diagnosis of sinonasal hemangiopericytomas were treated. The most common symptoms were obstruction (69%) and epistaxis (35%). All tumors were localized in the nasal cavity, and half had extension to 1 or more sinuses. Resection was performed endoscopically in 6 patients. Median intraoperative blood loss was 500 mL; median operative time was 165 minutes. Two patients received postoperative radiation. There were no recurrences with a median follow-up of 25 months. Three patients presented with recurrences, 2 local and 1 distant, up to 13 years after primary tumor removal.

CONCLUSION

Surgery for sinonasal hemangiopericytomas can be challenging; both endoscopic and open approaches may be used to treat these highly vascular tumors.

Immunohistochemistry in diagnosis of soft tissue tumours

Immunohistochemistry in soft tissue tumours, and especially sarcomas, is used to identify differentiation in the neoplastic cells. In some cases, specific antigens are expressed; however, an initial panel of antibodies is often required in order to establish the broad lineage, with a subsequent, more focused, panel to allow classification. Immunohistochemical evaluation must be employed with the clinical picture, the morphology, and, when necessary, other ancillary techniques such as molecular genetics and cytogenetics. Whereas some diagnoses are evident on morphology, many soft tissue neoplasms are seen microscopically as spindle cell, epithelioid cell, small round cell or pleomorphic tumours that need to be further characterized. This article reviews selected applications of immunohistochemistry in the diagnosis of each of the principal morphological groups, concentrating on areas of most use in daily practice.

Dermatofibrosarcoma protuberans: clinical, pathological, and genetic (COL1A1-PDGFB ) study with therapeutic implications

AIMS

To analyse the presence of collagen type I alpha 1-platelet-derived growth factor beta (COL1A1-PDGFB) transcripts in 20 cases of dermatofibrosarcoma protuberans (DFSP) and to assess the relationship between COL1A1 breakpoints and clinical and histopathological variables.

METHODS AND RESULTS

Multiplex reverse transcriptase-polymerase chain reaction was carried out using frozen tissue. Our series contained 14 men and six women. Histologically, most cases were of conventional type (n = 9), followed by fibrosarcoma (n = 4), Bednar tumour (n = 2), sclerosing (n = 2), myoid (n = 1) and atrophic (n = 1) DFSP, and giant cell fibroblastoma (n = 1). Immunohistochemistry revealed CD34 expression in 90% of cases. COL1A1-PDGFB fusion transcripts were present in 89% of cases (exons 18, 19, 20, 25, 26, 31, 33/34, 39, 40, 46, 47 and 48 of COL1A1 with exon 2 of PDGFB). There was no recurrence of DFSP in any of the 19 patients treated by Mohs surgery. A partial response was obtained in the two patients treated with imatinib.

CONCLUSIONS

The COL1A1-PDGFB fusion was present in all histological subtypes of DFSP, but not all cases expressed the fusion transcript. No association was observed between different COL1A1 breakpoints and clinicopathological parameters. Imatinib mesylate can be useful in locally advanced tumours and metastases.

A case of fibroblastic low-grade malignant peripheral nerve sheath tumor--a true neurofibrosarcoma

The authors report a case of low-grade retroperitoneal malignant peripheral nerve sheath tumor (MPNST) showing Schwannian and fibroblastic differentiation in individual tumor cells. The tumor was detected in a 29-year-old male and posed diagnostic difficulty because of the unusual morphologic and immunophenotypic features. Morphologic examination of the H&E sections revealed a rather circumscribed, highly vascular, moderately cellular spindle cell tumor. The neoplastic cells were arranged in vague, short fascicles, distributed haphazardly amid hemangiopericytoma-like vascular channels, and showed occasional whorls. Myxoid stroma and keloid-like collagen bundles were frequently seen. There were satellite nodules outside the main tumor mass and low mitotic activity but no necrosis. The tumor cells stained strongly and diffusely for both S-100 protein and CD34. Electron microscopy revealed cells with processes and focal lamina, and prominent rough endoplasmic reticulum. Although the capacity of MPNST to exhibit divergent differentiation is well known, fibroblastic differentiation is generally poorly and inconsistently documented. The present case represents an unambiguous demonstration of the co-expression within individual tumor cells of Schwannian and fibroblastic differentiation in a low-grade MPNST. The literature on this subject is reviewed.

Advancement of research on inflammatory myofibroblastic tumor of the liver

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm composed of transformed myofibroblastic spindle cells with infiltration of a large number of inflammatory cells and/or lymphocytes. The etiology of IMT remains unknown. IMT occurs at various sites and often affects young adults and children. IMT of the liver mostly arises in the right lobe of liver. Biopsy, computed tomography (CT) and magnetic resonance imaging (MRI) are beneficial to diagnosis and differential diagnosis. Vimentin, smooth muscle actin (SMA), muscle-specific actin (MSA) are often positive by immunohistochemistry. The prognosis of most patients is favorable after surgery. In this article, we reviewed the overseas and domestic literatures and summarized the advancement of research on the IMT of the liver about etiology, pathogenesis, clinical presentations, imaging feature, histological appearance, immunohistochemical and electron microscopic feature, diagnosis, differential diagnosis and therapy.

Low-grade fibrosarcoma—report on 39 not otherwise specified cases and comparison with defined low-grade fibrosarcoma types

AIMS

Low-grade fibrosarcomas are tumours that mainly affect the extremities and trunk of adults of either sex. Among these, low-grade fibromyxoid sarcoma (FMS), hyalinizing spindle cell tumour with giant collagen rosettes (HST) and sclerosing epithelioid fibrosarcoma (SEF) are well-established entities. In this study, our aim was to describe a group of low-grade fibrosarcomatous tumours, which could not be encompassed by these entities. These low-grade fibrosarcomas, not otherwise specified (FNOS) were provisionally designated as 'fibrosarcoma, low-grade fibroblastic type'.

METHODS AND RESULTS

In the soft tissue tumour registry we found 39 FNOS (46%), 31 FMS (36%), 11 SEF (13%) and four HST (5%). FNOS occurred in older patients than FMS (mean age 56.3 years versus 33.7 years). They mainly showed fibrous features, but myxoid areas could also be seen. While cells tended to be loosely arranged in the myxoid areas, densely packed sheets with a storiform pattern, fascicular arrangements or regions without a defined growth pattern were observed in the fibrous areas. However, neither whirling nor swirling patterns were found. Arcade-like vessels were not visible; pseudolipoblasts did not occur. FNOS exhibited increased atypia and mitotic count compared with the other sarcomas studied [FNOS, mean value 4.6 mitoses/10 high-power field (HPF); FMS, 0.7/10 HPF). Follow-up data were available in 21 FNOS patients. In seven cases (33.3%), local recurrences were reported. Three patients (14.3%) developed metastases and all of them died of tumour.

CONCLUSIONS

The term 'fibrosarcoma, low-grade fibroblastic type' should be used as a diagnosis of exclusion. Further studies should elucidate whether it represents a distinct fibrosarcoma type.