Histopathologic classification of parapharyngeal space tumors: a case series and review of the literature

The objective of the study is to present a large case series of parapharyngeal space tumors (PPST) and the most comprehensive literature review of tumor histopathologic distribution. The study was designed as internal case series and full Pubmed/MEDLINE electronic database review in a tertiary academic medical center. Tumor histopathology and patient demographics were obtained from a comprehensive Pubmed/MEDLINE database review, as well from an internal case series of 117 patients referred to our center between 1993 and 2013. Main outcome and measures of the study were to define the age, gender, and histopathology of PPST within a large internal case series and among the current body of published literature, and to propose a diagnostic and treatment algorithm for these tumors. Our cohort included 117 cases, 58 females and 59 males, with benign tumors comprising 85 % (n = 99) and malignant tumors 15 % (n = 18). A systematic review of published literature from 1963 to the present revealed 37 case series, and when combined with our present series, yielded a total of 2160 cases. Benign tumors are most common (78.8 %), with tumors of salivary gland (44.4 %), neural (34.4 %), and vascular (2.64 %) origin representing the largest subtypes. Pleomorphic adenomas (30.9 %), paragangliomas (13.1 %), and schwannomas (12.3 %) comprised the majority of all cases. Due to their rarity, data regarding the histopathologic distribution of PPST is scarce. We provide one of the largest case series and the most comprehensive review of these tumors in the literature to date, and offer our algorithm for evaluation and treatment.     

Our experiences with parapharyngeal space tumors and systematic review of the literature

Objectives  To find out the geographical distribution, age, sex, mode of presentation, diagnostic modalities, surgical approaches, postoperative complications, follow-up and histopathology of parapharyngeal space tumors (PFT) through world wide web search (WWWS) and PFT of our series. Materials and methods  A retrospective study of all PFT seen and treated in S.R.N Hospital, Allahabad between 1990 and 2006 was done. A systematic review of the literature was done through WWWS. Results  PFT were commonest in the Asian zone. Incidence was highest in the 3rd and 4th decade. Oropharyngeal (100%) and cervical (91.6%) swelling were the commonest presentation. MRI is better than CT scan in evaluating fat plane. Transcervical approach was the commonest. In our series, benign tumors (83.4%) were common, constituting 50% of neurogenic and 16.6% of salivary gland origin. Conclusion  PFT were more prevalent in the Asian zone. Neurogenic tumors were commonest in our study which contradicts the WWWS of having maximum PFT of salivary gland in origin.     

新生儿咽旁间隙卡梅现象1例并文献复习

目的 学习和掌握新生儿咽旁间隙卡梅现象(KMP)的临床特点、诊断及治疗方案的选择。 方法 回顾总结1例新生儿咽旁间隙KMP的诊疗过程,并复习相关文献。 结果 患儿先期治疗采用泼尼松和普萘洛尔联合口服效果不佳,后改用博来霉素、地塞米松混合液瘤体内灌注,分二期完成治疗,间隔1个月,瘤体消失,实验室检查正常。随访2年,患儿恢复良好,无不良反应出现及后遗症发生。 结论 KMP是一种对婴幼儿危害较大的罕见疾病,发生于咽旁间隙尤为少见,目前尚无统一治疗方案,需个体化制定治疗措施。病例提示对于难以手术切除和全身用药治疗效果不佳的患儿,博来霉素、地塞米松局部注射是安全有效的治疗手段。     

Synovial sarcoma in the parapharyngeal space: case report and review of the literature

We encountered a rare case of synovial sarcoma in the parapharynx of a 47-year-old Japanese man. This patient presented with an enlarging tumor in the right side of his neck that had grown progressively over a 4-week period. Radiological examinations revealed that the tumor arose from the parapharyngeal space. The tumor could not be completely removed at surgery. Metastasis to the lumbar vertebra was detected postoperatively. The patient underwent three courses of chemotherapy and the delivery of palliative radiation to the lumbar vertebra without success. The patient died of lung metastasis 7 months after surgery.     

Neurilemmoma of the parapharyngeal space. Report of three cases and review of the literature.

The clinical pre-operative diagnosis of parapharyngeal neurilemmoma is frequently missed. Bimanual palpation of the mass is the most rewarding clinical investigation. Intra-oral incisional biopsy is to be prescribed in case of benign tumor. Treatment is achieved by total excision by external approach. Recurrence rates in benign lesions are low but high with malignant tumors. Three cases of parapharyngeal neurilemmoma are presented.     

Surgical management of primary parapharyngeal space tumors: a 10-year review

Conclusions: Most neoplasms of the parapharyngeal space are benign. The transcervical surgical approach is the preferred procedure in most cases. Intra-operative endoscopic exploration offers a new surgical management technique to reduce operative complications and post-operative recurrence rates.

Objectives: To present the authors’ experience in the treatment of primary parapharyngeal space tumors with emphasis on surgical approaches and employment of endoscopy to detect residual tumors through conventional approaches.

Method: One hundred and sixty-seven patients treated surgically over a 10-year period were retrospectively reviewed. A comparison of the surgical approaches in a relevant case series was also conducted.

Results: All of the patients underwent pre-operative imaging before surgery, and intra-operative endoscopic detection was selectively used for large, deep tumors. Complete resection of the tumor was used in 158 patients (95%), with a transcervical surgical approach applied in 144 cases (84%). Of 167 tumors, 150 (90%) were benign and 17 (10%) were malignant, with neurilemmoma/schwannoma as the most frequent pathology (42%). Surgical complications were reported in 26 patients (15%), most commonly unilateral paralysis of the vocal cords (6%). Two patients (1%) presented with recurrence, on average 2.5 years (range = 1–4 years) after initial excision, and the mean follow-up time was 3.8 years (range = 10 months–10 years).     

Neurogenic tumors of the parapharyngeal space

Twelve patients with neurogenic tumors of the parapharyngeal space are reviewed. Ten of the tumors were benign and surgically removed. The two malignant tumors in this series, a malignant schwannoma and a neuroblastoma, were unresectible, and both of these patients died of their disease.     

A study of tumors of the parapharyngeal space.

A retrospective study of patients with parapharyngeal tumors has been completed, and this report concerns 40 patients cared for during the years 1962–1973. The parapharyngeal space is a potential anatomical space with three rigid walls so that growth of a tumor proceeds either medially or inferiorly or both. This pattern of growth accounts for the distinct clinical appearance of a displaced palate and pharynx. As noted in this series of cases, Table I depicts the types of tumors which involved the parapharyngeal space. Eighty-two percent of the cases presented with benign tumors. On the other hand, 18 percent of the patients had malignant tumors. Benign mixed cell tumors and schwannomas are the most commonly noted benign tumors. Several cases presented with unusual tumors. In most patients the tumor was discovered on routine physical examination. Arteriography has become a valuable and safe diagnostic study. These procedures often help the surgeon to determine the extent of tumor, vessel displacement and the possibility of chemodectoma and even malignancy in some patients. An external surgical approach is recommended for surgical excision of the benign parapharyngeal tumor in most patients. Intraoral incisional biopsy in patients with benign tumors is to be avoided because of dangers of vessel and nerve injury as well as “seeding” of the biopsy site. On the other hand, malignancy may be diagnosed with incisional biopsy either performed externally or intraorally, depending on the judgment of the surgeon as to the anatomical location and site of the neoplasm. In final analysis the external surgical approach allows the surgeon systematically to identify tumor, important cranial nerves including the facial nerve and the great vessels. Every effort should be made by the surgeon not to violate the capsule of a benign mixed tumor during its removal. Removal of tumor is enhanced frequently by preliminary excision of the submandibular gland, vessel ligation and mandibulotomy. In the latter instance the patient must undergo tracheostomy. Postoperative cranial nerve palsies occurred for the most part in those patients who underwent surgical excision of schwannomas. These tumors originated from the vagus nerve or cervical sympathetic chain. Sacrifice of these nerves during removal caused little morbidity. Follow-up examinations in this series of patients revealed that if benign tumors are removed from the parapharyngeal space in a deliberately planned manner, recurrence rates are extremely low. In patients who are treated for malignant lesions, prognosis must be guarded, as mortality rates are high regardless of the type of therapy.     

咽旁间隙肿瘤的诊断和治疗

目的:探讨咽旁间隙肿瘤的诊断和治疗.方法:回顾性总结我院22例咽旁间隙肿瘤的诊断和治疗经验.肿瘤位于左侧者14例,右侧者8例.所有患者均接受了手术治疗,经颈侧切开肿瘤切除19例,经颈侧下颌骨裂开肿瘤切除2例,经口肿瘤切除1例.结果:术后经病理证实,神经源性肿瘤15例,腮腺深叶肿瘤4例,其他类型3例.良性肿瘤18例(81.8%),恶性肿瘤4例(18.2%).2例恶性肿瘤患者分别于术后2年和3年因复发死亡,其余未见复发.4例行术前B超引导下穿刺活检的患者均准确区分良恶性.结论:咽旁间隙肿瘤通过病史及影像学检查可明确诊断,针吸活检有助于肿瘤性质的判定,手术是其治疗的主要手段.     

Clinical study of parapharyngeal space tumors

We clinically studied 31 cases of parapharyngeal space tumor treated between 1988 and 2002, and compared histological findings and preoperative diagnosis. Pleomorphic adenoma was the predominant tumor, accounting for 35.5%. Schwannoma and paraganglioma were next at 26.6%. In determining pathological diagnosis, fine needle biopsy and imaging were useful. Important factors in imaging diagnosis are inspecting the degree of enhancement in CT or MRI, investigating the existence of flow void on MRI, and discriminating whether the origin is pre- or post-styloid.     

咽旁隙肿瘤的诊断及治疗

目的 了解咽旁隙解剖特征，提高咽旁隙肿瘤诊治水平。方法回顾分析近9年收治的45例咽旁隙肿瘤病人临床表现、影像学特征、外科径路、手术所见及手术后并发症，全部病人随访8个月～9年。结果良性肿瘤40例(其中神经源性肿瘤28例)，恶性肿瘤5例。术前CT或MRI能明确肿瘤的大小、位置、扩展范围、以及与周围结构的关系。术后出现伸舌偏斜2例，口角偏斜1例，Hoiner综合征4例，右上肢曲屈障碍1例，3例术后肿瘤复发再次手术治愈。结论原发性咽旁隙肿瘤以神经源性肿瘤多见，MRI和/或CT检查是诊断咽旁隙肿瘤及术前确定手术方案的基础，且MRI检查优于CT。根据病变的部位及特性，手术可选择经口径路、颈侧径路或颈侧联合径路切除肿瘤。     

咽旁隙肿瘤的手术治疗

目的探讨咽旁隙肿瘤的诊断及手术入路的选择。方法回顾性分析经手术诊断及治疗的52例咽旁隙肿瘤的临床资料,包括症状、体征、手术入路及术后病理结果。结果52例患者中23例（44.2%）经颈侧入路,14例（27%）经腮腺颈侧（腮颈）入路,10例（19.2%）为颈侧下颌骨入路,5例（9.6%）经口内入路。术后病理良性占80.8%,恶性19.2%。唾液腺及神经源性肿瘤分别占总数的46.2%和28.8%。52例患者中48例行Ⅰ期手术切除,术后恶性肿瘤复发率30% (3/10),良性肿瘤复发率7.1%(3/42)。结论术前运用影像学及组织病理学手段判断肿瘤性质及与周围重要结构的关系对于制定和完善手术计划至关重要,选择合适的手术入路有助于术中充分暴露肿瘤,提高手术安全性和减少术后并发症。     

Surgical management of parapharyngeal space tumors

Despite its rarity, information on the diagnosis of parapharyngeal space tumors such as through imaging and aspiration biopsy cytology, is slowly accumulating. Little detailed examination has been conducted, however, on surgical approach, complications, and sequelae. We report the results of a retrospective review of 27 patients with primary parapharyngeal space tumors-25 with benign disease and 2 with malignant lesions-treated surgically. Surgical approach, postoperative complications, sequelae, and operative indications of parapharyngeal space tumors were examined in 28 operations on the 27 patients. Tumors found in the prestyloid region in CT or MRI are treated as salivary gland or malignant tumors. Those found in the poststyloid region are treated as shwannoma or paraganglioma. The transcervical approach is often used in patients with shwannoma, while a variety of approaches are selected for patients with salivary gland tumors. Complications occur in 50% of patients, however, bias based on pathological diagnosis has not been examined to the degree needed. Sequelae in our series occurred in 46.4% of our patients. Sequela in the patients with shwannoma, however, is 81.8%, compared to 9.1% in patients with salivary gland tumors. Prestyloid parapharyngeal space tumors seem to be "automatically" indicated for surgery, because the surgical risk is lower than the risk of inaction. In poststyloid parapharyngeal space tumors, however, it appears necessary to judge indication for surgery more carefully while considering the social background, age, and occupation of prospective surgical candidates.     

Tumors of the parapharyngeal space. Topographical anatomy, diagnosis, therapy, literature review

The borders of the parapharyngeal space are formed of fasciae of muscular tissue. Its lateral border is formed by the bone of the mandible, while its cranial border is formed by the petrous bone. The initial symptoms of parapharyngeal tumors are diagnostically volatile because of the soft tissue contents of the parapharyngeal borders. For diagnostic reasons, it has to be decided whether to extirpate tumor immediately in order to obtain a specimen for histological evaluation or whether extensive presurgical examinations are necessary. Aside from multiple serological investigations for infectious diseases, these include all kinds of noninvasive morphological procedures such as CT scan, MR scan, transcutaneous and endoscopic B-mode sonography. In addition, invasive procedures such as arterial angiographies and the taking of specimens may be necessary in some cases.     

原发性咽旁间隙肿瘤的诊断与治疗

目的 总结原发性咽旁间隙肿瘤的临床特征、诊断方法、手术方法及疗效.方法 回顾性分析解放军总医院2006年1月至2008年12月收治的40例原发性咽旁肿瘤患者的临床资料,其中男22例,女18例;年龄1 ～77岁,中位年龄42岁.CT扫描结合MRI检查有助于咽旁间隙肿瘤的诊断和手术方案的制定.手术方式包括:经口入路1例,经颈部入路22例,经腮腺-颈部入路8例,下颌升支纵行裂开入路1例,经颈部-下颌角部分切除入路4例,经腮腺进路2例,耳后颅颈联合入路2例.结果 40例患者均经手术切除,术后病理诊断良性肿瘤28例,恶性肿瘤12例,其中涎腺来源15例,神经来源12例,其余13例为其他组织来源.28例良性肿瘤中,23例经一次手术治愈,随访13～47个月无复发,中位数39个月.12例恶性肿瘤经随访3～50个月,中位数29个月,6例存活(随访时间24～ 50个月,中位数36个月),3例在术后6个月内死亡,3例失访.术后发生脑脊液漏1例,术腔感染2例,迷走神经损伤3例.结论 手术切除是治疗咽旁间隙肿瘤的首选方法,绝大多数肿瘤可以经单纯颈侧入路切除;对于恶性肿瘤或较大的良性肿瘤应选择较宽阔的手术入路.咽旁间隙的良性肿瘤预后较好,而恶性肿瘤组织类型复杂多样,治疗效果差,预后不良.     

Management of tumors arising in the parapharyngeal space

Tumors originating in the parapharyngeal space are rare. During the period of January 1977 to July 1989, 51 patients underwent surgery for parapharyngeal space tumors at the University of Pittsburgh's Eye and Ear Hospital. Eighty percent of the parapharyngeal space neoplasms were benign; 20% were malignant. Fifty-seven percent (31/54) were of neurogenic origin, 30% (16/54) were of salivary origin, and 13% (7/54) were of miscellaneous origin. The use of computed tomography scan and magnetic resonance imaging, and selective use of angiography, allowed us to ascertain the location, size, vascularity, and relation of parapharyngeal space tumors to surrounding anatomical structures. Imaging techniques established the site of origin of these tumors with 96% accuracy. This information was essential in planning surgical approaches and predicting prognoses. Details of the surgery, morbidity, and outcome of these patients are presented.