Two New Localizations of Solitary Fibrous Tumor in the Italian Population: Parotid Gland and Oral Cavity—Review of the Literature

Head and Neck Solitary Fibrous Tumor Presenting as Salivary Gland Tumor: Two Case Reports and Review of the Literature

Solitary fibrous tumors (SFTs) are soft tumors (mesenchymal origin) that most likely develop from adult mesenchymal stem cells. SFTs are not common in the head and neck region, and the characteristics of tumors in this location are unclear. The present study describes the clinicopathological findings of 2 cases of SFTs arising in the parotid gland and buccal space, presenting as salivary gland tumors. The first case is a 76-year-old man presenting with a painless tumor on the right parotid gland who subsequently underwent partial superficial parotidectomy. According to the results of histopathological analysis, the tumor consisted of stellate and spindle-shaped cells proliferating on a mucous-like substrate. Immunohistochemical staining revealed that neoplastic cells were positive for CD34, vimentin, Bcl2, and STAT6. The second case is of a 64-year-old man presenting with a painless lump on his right cheek. Based on the findings of fine needle aspiration cytology, a tumor derived from myoepithelial cells of the minor salivary gland or a nonepithelial tumor was suspected. The patient underwent surgical resection via an intraoral approach. Histopathologically, the tumor consisted of spindle-shaped cells with rod-shaped or irregular nuclei. Immunohistochemical staining revealed that the neoplastic cells were positive for CD34, CD99, Bcl2, and STAT6. Briefly, SFT should be considered in the differential diagnosis of a well-marginalized lesion in the salivary gland and oral cavity. STAT6 immunohistochemistry is the most specific and sensitive method of diagnosing SFT. A thorough understanding of the morphological changes associated with SFT and their correlation with clinical, immunohistochemical, and molecular characteristics is important to avoid misdiagnosis.

Parotid Gland Solitary Fibrous Tumor Presenting as a Long Duration Mass: A Case Report

The solitary fibrous tumor (SFT) is a tumor of uncertain histogenesis, affecting deep soft tissues, particularly the pleura (pulmonary) and extrapulmonary sites including thighs, retroperitoneum, other serosal surfaces, and cranial and spinal meninges. SFT and hemangiopericytoma are now considered the same entity, with general agreement on referring to this group of tumors as “SFT.” SFTs are generally benign tumors with small subsets of malignant ones. Moreover, they are well-circumscribed with a good prognosis after surgical resection. SFTs are uncommon in the head and neck and are quite rare in the parotid gland region. Here, we present a case of a 48-year-old female with SFT of the parotid gland region; the diagnosis was confirmed by positive immunohistochemical staining for Bcl-2, CD34, and STAT6. STAT6 immunohistochemistry is sensitive and specific for SFTs.

Surgical approach to parotid pleomorphic adenoma: a 15-year retrospective cohort study

Our aim was to investigate the clinical outcomes (recurrences, duration of follow-up, and effectiveness) after extracapsular dissection and superficial parotidectomy for pleomorphic adenoma of the parotid gland. We retrospectively studied 261 patients whose adenomas were treated at the Maxillofacial Unit of Magna Graecia University of Catanzaro between January 2003 and December 2015 and had been followed up for at least three years after either extracapsular dissection or superficial parotidectomy. The difference in recurrences and complications between the two techniques were measured by univariate analysis (Fisher's exact test). The level of significance was set at p ≤ 0.05. Of the 261 patients 125 were male (48%) and 136 female (52%), mean (range) age 47 (14-78) years. A total of 210 of the 261 patients had an extracapsular dissection (80%, 101 male and 109 female), and 51 had a superficial parotidectomy (24 male and 27 female). Postoperative complications were recorded in 48 of the 261 patients; complication rate was 10% in the extracapsular dissection group, and a third after superficial parotidectomy. There were more complications in the parotidectomy group (p=0.042). For pleomorphic adenomas located in the superficial portion of the parotid gland, extracapsular dissection is a viable alternative to traditional superficial parotidectomy in the hands of experienced parotid surgeons with regard to clinical outcomes, and it may be superior with regard to cost.

Diagnosis of solitary fibrous tumor in the submandibular gland: Case report and literature review

Solitary fibrous tumors (SFTs) rarely occur in the head and neck area. Imaging findings are nonspecific, and immunohistochemical (IHC) analysis is necessary for a definitive diagnosis. We report the case of a patient with a mass in the submandibular region that was initially diagnosed as basal cell adenoma. After excision and IHC examinations, a SFT was diagnosed.

Solitary fibrous tumour of the parotid gland: a case report and a 15-year literature review

Solitary fibrous tumour (SFT) is uncommonly found in the salivary glands and is a rare group of spindle-cell tumours. A review of literature revealed only 40 reported cases of SFT of major salivary glands over a 15-year period from 2004 to 2018. SFTs of the salivary glands are usually benign, although rarely, can be aggressive and may sometimes recur after initial resection. Histology and Immunohistochemistry are the most important criteria to distinguish SFT from other head and neck tumours. SFTs strongly stain for CD34 and hence is the most frequently used stain for diagnosis. All reported SFT cases with available information on immunohistochemical stains were positive for CD34. Recently, immunohistochemistry for STAT6 has been introduced as a surrogate diagnostic marker for SFT that is highly sensitive and specific. We report a case of a 51-year-old Chinese gentleman who presents with a 3-month history of a left parotid tumour that required a subtotal parotidectomy for complete excision. It was diagnosed as SFT based on histology and immunohistochemical features. He was followed-up for 3 months post-operatively with no clinical evidence of recurrence. This case proposes that, although rare, SFT should be considered in the differential diagnosis of soft-tissue tumors in the major salivary glands. An awareness of this rare entity will help clinicians and pathologists better manage similar patients in the future.

A dedifferentiated solitary fibrous tumor of the parotid gland: a case report with Cytopathologic findings and review of the literature

Background

Solitary fibrous tumor (SFT) is a ubiquitous mesenchymal neoplasm but it rarely occurs in the parotid gland. The histological features are variable, with the majority having spindle cell morphology and non-specific branching (staghorn) ecstatic vascular pattern. SFT ranges from benign to overtly malignant. Dedifferentiation within SFTs represents an abrupt transition from a well-differentiated component to a high-grade area, the latter most often including poorly differentiated epithelioid/round cell or high-grade spindle cell morphology. To the best of our knowledge, dedifferentiated SFT in the parotid gland has not been previously reported.

Case presentation

A 33-year-old woman presented with a soft tissue tumor in the right parotid gland that had been present for 6 months. Fine needle aspiration (FNA) cytology indicated epithelioid morphology in the dedifferentiated component of the tumor, along with metachromatic myxoid matrix. The tumor was initially interpreted as a salivary gland neoplasm of uncertain malignant potential (SUMP).Right partial parotidectomy was performed, and microscopic examination of the resected specimen revealed a malignant spindle cell tumor with a central epithelioid/anaplastic component. The tumor cells were diffusely positive for CD34, STAT-6 and FLI-1, and negative for pan-cytokeratin, CAM5.2, p63, S100 protein, CD31, SMA, and calponin.ERG and Ki67 immunostaining showed an accentuated nuclear staining pattern in the central dedifferentiated area. There was no overexpression of p53 or p16. The patient is currently undergoing regular follow-up and is 11 months postresection with no evidence of recurrence or distant metastasis.

Conclusions

Unlike the typical spindle cell morphology of conventional SFTs, malignant SFTs can show areas of dedifferentiation mimicking an epithelial neoplasm. FNA of dedifferentiated SFTs of the parotid gland may show, a combination of atypical epithelioid cells and metachromatic myxoid/collagenous matrix, which is a less emphasized cytological feature of SFT and may lead to misdiagnosis as a more common parotid gland epithelial neoplasm.

Solitary fibrous tumor occurring in the parotid gland: a case report

Background

Solitary fibrous tumor is an uncommon spindle cell neoplasm of unknown origin. It has been reported in many anatomic sites, with a rare occurrence in the head and neck region. Solitary fibrous tumors of the parotid gland are exceptional; their clinical and radiologic features are non specific, often mimicking more common salivary gland tumors. Pathologic examination and immunohistochemistry are required to make the correct diagnosis. The prognosis is favorable, with most tumors being benign, and complete surgical resection is the treatment of choice.

Case presentation

We report the case of a 42-year-old man who presented with a painless mass involving the parotid gland. A parotidectomy was performed, and follow up was unremarkable. Gross examination showed a well circumscribed, firm tumor measuring 3,4 cm. Histologically, the tumor was composed of a spindle cell proliferation of variable cellularity, with staghorn vessels. A panel of immunohistochemical stains was performed, and confirmed the diagnosis of parotid gland solitary fibrous tumor.

Conclusion

In this report we aim to increase awareness of this rare entity among clinicians and pathologists, and to emphasize the role of immunohistochemistry in confirming the diagnosis.

Solitary Fibrous Tumor of the Tongue: An Uncommon Cause of Obstructive Sleep Apnea

Introduction

Solitary fibrous tumor is an uncommon mesenchymal neoplasm that may be found in any location. To date, only a few cases of solitary fibrous tumor involving the tongue have been reported.

Case Summary

We present the case of a 31-year-old man with a history of progressively worsening snoring and daytime sleepiness. Polysomnography revealed severe obstructive sleep apnea. An attempt to treat sleep apnea by continuous positive airway pressure and oral appliance led to a poor clinical response. CT and MRI scans findings revealed a large mass in the tongue base partially obstructing the airway. After the excision of the mass all symptoms, included daytime somnolence, disappeared and a polysomnographic examination showed the normalization of the somnographic parameters.

Discussion

Although OSA is rarely caused by tumors, each patient with sleep disorders breathing should be examined carefully for the potential presence of an upper aero-digestive tract neoplasm that may contribute to obstruction.

Pleomorphic adenoma of the parotid: extracapsular dissection compared with superficial parotidectomy--a 10-year retrospective cohort study

The purpose of this study was to investigate the complication rates and effectiveness of extracapsular dissection compared with superficial parotidectomy for pleomorphic adenomas of the parotid gland from 2002 to 2012. The authors carried out a retrospective cohort study of 198 patients with pleomorphic adenomas of the parotid gland. Extracapsular dissection (ED) or superficial parotidectomy (SP) was performed. The recurrence rate and complications of the two surgical techniques were measured with a univariate analysis of each variable using the appropriate statistical analysis (chi-squared test or t-test). A total of 198 patients were enrolled between January 2003 and December 2012. The study included 97 females (48.99%) and 101 males (51.01%) whose mean age was 50.97 years (range 14–75). The type of surgery performed was ED in 153 patients (77.27%, 80 males and 73 females) and SP in 45 patients (22.73%, 21 males and 24 females). The mean follow-up time was 61.02 +/− 4.9 months for the patients treated with ED and 66.4 +/− 4.5 months for the patients treated with SP. Transient facial nerve injury and facial paralysis were significantly more frequent after SP than after ED (P = 0.001 and P = 0.065, resp.). No significant differences in capsular rupture, recurrence, and salivary fistula were observed after SP or ED: 2.2% versus 3.9%, 2.2% versus 3.3%, and 2.2% versus 0.65%, respectively. Extracapsular dissection may be considered the treatment of choice for pleomorphic adenomas located in the superficial portion of the parotid gland because this technique showed similar effectiveness and fewer side effects than superficial parotidectomy.

Solitary fibrous tumor of the parotid gland: Case report

Solitary fibrous tumor (SFT) is a rare spindle cell neoplasm that usually develops in the pleura and peritoneum. The head and neck region is involved in only 6% of the cases. Involvement of the parotid gland is a rare phenomenon, with only 24 cases reported in the literature. The aim of this study is to report an additional case of SFT affecting the parotid gland, and to review the literature on previously reported cases. The patient was a 42-year-old male with a 4-cm, fibro-elastic, movable, painless nodule in the inferior lobe of the parotid gland. The lesion was surgically excised and, following histopathological and immunohistochemical analysis, a diagnosis of SFT was rendered. The patient has been followed-up for ten months, with no signs of recurrence. Clinical, histopathological, immunohistochemical and treatment aspects of the tumor are discussed.

Key words:Solitary fibrous tumor, parotid gland, case report.