Loss of CD34 and high IGF2 are associated with malignant transformation in solitary fibrous tumors

Solitary fibrous tumor within the mesorectum: literature review based on a case report of resection by transanal minimally invasive surgery (TAMIS)

PURPOSE

Solitary fibrous tumors (SFT) are a rare entity of in majority benign neoplasms. Nevertheless, up to 20% of cases show a malignant tendency with local infiltration or metastasis. Commonly arising in the thoracic cavity, only few cases of SFT of the mesorectal tissue have been reported in the literature. Complete surgical resection, classically by posterior approach, is the treatment of choice. The purpose of this review is to demonstrate the safety and suitability of transanal minimally invasive surgery (TAMIS) as a surgical approach for the resection of benign pararectal solid tumors.

METHODS

We report the case of a 52-year-old man who was diagnosed incidentally with SFT of the distal mesorectum. Resection by TAMIS was performed. Based on this case, we describe the steps and potential benefits of this procedure and provide a comprehensive review of the literature.

RESULTS

Histopathology confirms the completely resected SFT. After uneventful postoperative course and discharge on day four, follow-up was recommended by a multidisciplinary board by clinical examination and MRI, which showed a well-healed scar and no recurrence up to 3 years after resection.

CONCLUSION

SFT of the mesorectum is a very rare entity. To our knowledge, this is the first report on a TAMIS resection for SFT, demonstrated as a safe approach for complete resection of benign pararectal solid tumors.

Toward Better Understanding and Management of Solitary Fibrous Tumor

Solitary fibrous tumor (SFT) comprises a histologic spectrum of soft tissue neoplasms that are characterized by the unique NAB2-STAT6 gene fusion. Changes in diagnostic terminology and site-specific classification over the past few decades have resulted in a disjointed literature. Complete surgical excision with preservation of function remains the mainstay of treatment. New risk stratification systems including risk factors such as mitotic rate, age, tumor size, and presence of necrosis, among others, can be used to predict risk of recurrence or metastasis. Long-term follow-up after surgical resection is recommended. The clinical manifestations, diagnosis, management, and prognosis of SFT are reviewed here.

De-differentiation associated with drop metastasis of a recurrent intracranial solitary fibrous tumor: a case report and literature review

BACKGROUND

Central nervous system is a rare occurring location of solitary fibrous tumors (SFTs). SFTs have a potential for recurrence, which is the leading cause of death in patients with these disease entities. De-differentiation phenomenon combined with cerebrospinal fluid (CSF) dissemination through drop metastasis of STFs from intracranial to intraspinal has only been reported in extremely limited cases.

CASE DESCRIPTION

Herein, we present a case of SFT in a 54-year old male. MRI showed characteristic of mixed high and low signal with 6.3 cm × 6.5 cm × 5.9 cm. After radical surgical resection, the pathology indicated benign SFT. However, MRI re-examination of 22 months later detected local recurrence, concomitant with spreading of intracranial and intraspinal through CSF dissemination. And interestingly, the second pathology found de-differentiation phenomenon and malignance of SFT, in which some areas transformed to rhabdomyosarcoma.

CONCLUSION

This is the first case report of recurrent intracranial SFT de-differentiating to rhabdomyosarcoma concurrent with CSF pathway drop metastasis. Benign intracranial SFTs have the potential of de-differentiation, which may play an important role in its distant metastasis. The underlying molecular biological and pathological mechanisms of benign SFT malignance transformation still warrant further exploration.

Non-adrenal tumors of the adrenal area; what are the pitfalls?

Discovery of an adrenal mass is nowadays a frequent situation. While adrenal tumors can cause a variety of symptoms, more often than not they are diagnosed incidentally on imaging exams such as CT-scan or MRI performed for another purpose. However, any retroperitoneal supra-renal mass can have an extra-adrenal origin. Indeed, operated non-adrenal masses initially but wrongly diagnosed as an adrenal disease represent about 3.5% of adrenalectomies. These differential diagnoses principally include retroperitoneal tumors that are malignant in two thirds of cases (lymphomas, sarcomas, neurogenic or germinal tumors), and more rarely vascular anomalies or congenital malformations, which are most frequently left-sided due to the wide variety of anatomical structures surrounding the left adrenal gland. Several lesions can originate from the adrenal gland or be located near the gland (paraganglioma, ganglioneuroma). Even though unilateral adrenalectomy is associated with low morbidity, ignorance of these differential diagnoses can cause ill-adapted management; overly conservative surgery in case of sarcoma is one example. Some of these lesions have characteristic clinical or imaging features (cystic lymphangioma, angiomyolipoma…). In other cases, assessment of hormonal secretion is required and additional exams (MRI, percutaneous biopsy, PET-scan with 18-Fluorodeoxyglucose) can correct an erroneous diagnosis. The above diagnostic approach allows appropriate management (with or without surgery). The purpose of this review was to highlight the main differential diagnoses of adrenal masses, to describe their characteristics, and to discuss their therapeutic management.

Solitary fibrous tumour of the sigmoid colon mesentery

Solitary fibrous tumours (SFTs) are rare tumours arising from mesenchymal tissues. Despite of their more frequent occurrence in the pleura, SFT can present anywhere in the body. Only a few cases have been described arising from the mesentery. Most tumours have a benign nature; however, up to 20% of them can spread, most commonly to liver, lung and bone. Surgical excision including all surrounding tissues remains the treatment of choice; however, there is no consensus regarding the need for adjuvant therapies. We present a 79-year-old man with abdominal pain who was found to have a SFT in the mesentery of the sigmoid colon, treated with en bloc resection. A multidisciplinary team including surgeons, medical and radiation oncologists is recommended in the care of these patients.

Fat-forming Solitary Fibrous Tumor of the Kidney - A Case Report and Literature Review

Fat-forming solitary fibrous tumors arising from the kidney are extremely rare, with only few cases reported so far. We report the case of a 49-year-old patient investigated for lumbar pain and diagnosed preoperatively with a large retroperitoneal tumor destroying the right kidney. The patient was submitted to surgery, the tumor being resected en bloc with right nephrectomy. The histopathological studies demonstrated the presence of a hemangiopericytoma-like tumor with adipocytary component; the immunohistochemical studies demonstrated the presence of cluster of differentiation 34 (CD34), while human melanoma black (HMB45) staining was negative. Therefore, the diagnostic of fat-forming solitary fibrous tumor of the kidney was established. The postoperative outcome was uneventful, the patient being discharged on the sixth postoperative day. In conclusion, although fat-forming solitary fibrous tumor of the kidney is a very rare entity, this diagnosis should be taken into consideration whenever a large retroperitoneal mass with high adipose content and renal invasion is described at the preoperative studies.

Overexpression of IGF2 and IGF2 receptor in malignant solitary fibrous tumor with hypoglycemia: a case report

Background

Solitary fibrous tumor (SFT) is a prototypical mesenchymal neoplasm that induces non-islet cell tumor hypoglycemia (NICTH) due to overproduction of insulin-like growth factor 2 (IGF2). We here report the case of a malignant SFT associated with a hypoglycemia attack.

Case presentation

An 81-year-old man with a large subphrenic mass presented with hypoglycemia and loss of consciousness. His serum insulin and IGF1 levels were relatively low, suggesting an excessively high serum IGF2 levels. Preoperative Western blotting of serum confirmed the overproduction of high-molecular-weight IGF2. After total tumor resection, the patient recovered from hypoglycemia without the need for further treatment. Histological examination revealed proliferation of spindle cells and frequent nuclear mitoses with STAT6 and CD34 immunoreactivity, which led to the diagnosis of malignant SFT. IGF2 was strongly upregulated in the tumor upon immunohistochemistry, consistent with the report of NICTH. In addition, the tumor expressed IGF2 receptor (IGF2R) but not IGF1R.

Conclusions

The present results indicate that the tumor co-expressed IGF2 and IGF2R. IGF2R has not previously been recognized as a tyrosine kinase receptor participating in cell signal transduction. Thus, further case series are required to determine whether IGF2R overexpression reflects the action of an unknown autocrine/paracrine system involving IGF2 for cell proliferation or for the scavenging and degradation of IGF2.

A Solitary Fibrous Tumor of the Subglottic Larynx: Case Report and Literature Review

BACKGROUND

Solitary fibrous tumors (SFT) arising from the larynx are extremely rare; most occur in the supraglottic larynx.

CASE REPORT

Herein, we detail a new case of a subglottic SFT presenting as a well-encapsulated soft-tissue tumor with hoarseness. It showed isoattenuation, similar to the adjacent muscle on pre-contrast computed tomography (CT) images, and strong, heterogeneous enhancement following contrast material administration, which may reflect hypervascularity. On pathological examination, it consisted of spindle cells, squeezed between abundant collagen, and focally prominent vascularity in a staghorn feature. The tumor cells were immunoreactive for CD34, BCL2 and CD99. Based on the combination of architectural and immunohistochemical criteria, we ultimately diagnosed this case as an SFT.

CONCLUSION

Until now, only 14 cases of laryngeal SFT have been described in the literature: 13 located in the supraglottic areas and only one located in the subglottic/tracheal area. Therefore the present case is the second case of a subglottic SFT reported. Although rare, SFT should be included in the differential diagnosis of a well-marginated laryngeal mass with highly intense contrast enhancement, which suggests rich tumor vascularity.

Morphological and Molecular Characterization of Human Dermal Lymphatic Collectors

Millions of patients suffer from lymphedema worldwide. Supporting the contractility of lymphatic collectors is an attractive target for pharmacological therapy of lymphedema. However, lymphatics have mostly been studied in animals, while the cellular and molecular characteristics of human lymphatic collectors are largely unknown. We studied epifascial lymphatic collectors of the thigh, which were isolated for autologous transplantations. Our immunohistological studies identify additional markers for LECs (vimentin, CCBE1). We show and confirm differences between initial and collecting lymphatics concerning the markers ESAM1, D2-40 and LYVE-1. Our transmission electron microscopic studies reveal two types of smooth muscle cells (SMCs) in the media of the collectors with dark and light cytoplasm. We observed vasa vasorum in the media of the largest collectors, as well as interstitial Cajal-like cells, which are highly ramified cells with long processes, caveolae, and lacking a basal lamina. They are in close contact with SMCs, which possess multiple caveolae at the contact sites. Immunohistologically we identified such cells with antibodies against vimentin and PDGFRα, but not CD34 and cKIT. With Next Generation Sequencing we searched for highly expressed genes in the media of lymphatic collectors, and found therapeutic targets, suitable for acceleration of lymphatic contractility, such as neuropeptide Y receptors 1, and 5; tachykinin receptors 1, and 2; purinergic receptors P2RX1, and 6, P2RY12, 13, and 14; 5-hydroxytryptamine receptors HTR2B, and 3C; and adrenoceptors α2A,B,C. Our studies represent the first comprehensive characterization of human epifascial lymphatic collectors, as a prerequisite for diagnosis and therapy.

Solitary Fibrous Tumor of the Sigmoid Colon Masquerading as an Adnexal Neoplasm

Solitary fibrous tumor is a rare, benign spindle cell neoplasm that was first described in the thoracic pleura. This tumor is now known to occur at many extrapleural sites. There are established criteria for the diagnosis of malignant solitary fibrous tumor including ≥4 mitotic figures per 10 high-power fields, increased cellularity, cytologic atypia, infiltrative margins, and/or necrosis. Although all solitary fibrous tumors have the potential to recur or metastasize, those with malignant histologic features tend to behave more aggressively. We report a case of solitary fibrous tumor, with malignant histologic features, in a 21-year-old woman which arose from the serosal surface of the sigmoid colon.

Lipomatous hemangiopericytoma in a child: A case report with immunohistochemical evaluation

Lipomatous hemangiopericytomas are rare soft-tissue tumors that show areas of hemangiopericytoma like vascular pattern admixed with lipid containing cells. It is now considered a subtype of solitary fibrous tumor due to histopathological and immunohistochemical similarities. To date, only a few cases have been adequately reported in the medical literature. A case of lipomatous hemangiopericytoma in an 11-year-old female patient is presented and the clinical, histopathological and immunohistochemical features are discussed, along with a literature review. To the best of our knowledge, this is the first known case of a lipomatous hemangiopericytoma in a pediatric patient. Our case report further emphasizes that a number of studies should be evaluated to delineate hemangiopericytomas from solitary fibrous tumors.

Pleural fat-forming variant of solitary fibrous tumor

The fat-forming variant of solitary fibrous tumor is rare. It occurs predominantly in the deep soft tissues of the retroperitoneum and thigh. We describe a case of fat-forming solitary fibrous tumor arising from the pleura, which was successfully treated using a video-assisted thoracoscopic approach. The patient remained free of recurrence 2 years after surgery and continues to be under long-term follow-up.

Head and neck solitary fibrous tumors: a rare and challenging entity

The objective of this study is to analyze the outcome of treatment for solitary fibrous tumors (SFTs) in the head and neck area. SFTs present as slow-growing masses, often with local compressive symptoms that are difficult to distinguish from other soft-tissue tumors. SFTs are commonly treated using local excision without adjuvant therapy. To date, only heterogeneous small series have been published, documenting the treatment results and outcome with these tumors. Retrospective study of patients with histopathologically confirmed SFT treated at two tertiary referral hospitals between 2004 and 2014. Eight men and four women with histologically confirmed SFT were identified in the records. Their age range was 37-82 years (mean 57.8 years). The mean follow-up period for eight patients was 6.75 years (range 1-24 years). Four patients were lost to follow-up. Sublocalizations were neck (n = 3), orbit (n = 2), paranasal sinus (n = 2), cheek (n = 2), hard palate (n = 1), parotid gland (n = 1), and tongue (n = 1). The first-line treatment for all of the tumors identified was surgical excision. In four cases, the surgical margins were narrow or unclear due to piecemeal resection in the paranasal sinus and orbit (n = 3) or a tumor location deep in the parapharyngeal space (n = 1). Recurrences developed in two of these cases (in the orbit and parapharyngeal space), and the other two patients were lost to follow-up. Radiotherapy and chemotherapy were not administered as first-line treatments. Overall, the local recurrence rate (n = 2/8) was 25 %. The disease-specific survival rate was 100 %. These results are consistent with the literature data and show that safe surgical excision, without opening of the tumor capsule, reduces the risk of local recurrence and leads to a favorable outcome. Tumors in the head and neck often represent a surgical challenge, and wide surgical margins are rarely possible due to the complex three-dimensional anatomic compartments in the region. Head and neck surgeons should therefore be aware that there is an increased risk of recurrence in these patients; tightly scheduled follow-up visits are mandatory for at least 10 years, if not longer. Radiotherapy only appears to be an option in patients with unresectable tumors or when wide surgical excision would cause severe functional morbidity.