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Year : 2010  |  Volume : 47  |  Issue : 1  |  Page : 86--87

Hemangiopericytoma of the parapharyngeal space: An uncommon tumor in an unusual site

K Dimri, VK Nimbran, A Kumar, B Rai 
 Department of Radiotherapy, Government Medical College and Hospital, Sector-32, Chandigarh-160 030, India

Correspondence Address:
K Dimri
Department of Radiotherapy, Government Medical College and Hospital, Sector-32, Chandigarh-160 030
India




How to cite this article:
Dimri K, Nimbran V K, Kumar A, Rai B. Hemangiopericytoma of the parapharyngeal space: An uncommon tumor in an unusual site.Indian J Cancer 2010;47:86-87


How to cite this URL:
Dimri K, Nimbran V K, Kumar A, Rai B. Hemangiopericytoma of the parapharyngeal space: An uncommon tumor in an unusual site. Indian J Cancer [serial online] 2010 [cited 2022 Jan 25 ];47:86-87
Available from: https://www.indianjcancer.com/text.asp?2010/47/1/86/58874


Full Text

Sir,

A 30-year-old male presented with a history of a painless mass on the left side of his face, of a four-year duration. The swelling was insidious in onset and gradually progressed to the present size of 7 x 6 cm. There was no clinical evidence of facial nerve involvement or cervical lymphadenopathy. Systemic clinical examination was unremarkable and an X-ray of the chest was normal. An MRI Scan revealed an 8.5 x 7.5 x 6.0 cm, well-marginated, heterogeneous mass, with solid and cystic components, in the left parapharyngeal space [Figure 1]. Moderate enhancement was seen in the post contrast study [Figure 2]. The mass compressed the left parotid gland, caused a bulge in the left maxillary sinus along its posterolateral aspect and extended into the left infratemporal fossa. There was, however, no evidence of invasion. Fine needle aspiration cytology of the lesion suggested a spindle cell tumor.

The patient underwent left parapharyngeal tumor excision via a temporal, transparotid, and transmandibular approach following superficial parotidectomy. Preoperatively, the tumor was smooth, encapsulated, and the parotid gland was uninvolved. Microscopically, it was a highly cellular mesenchymal tumor, with mildly pleomorphic, plump, oval to spindle cells, arranged around vessels of varying caliber, in a pericytoma pattern. Final histopathology and immunohistochemistry were suggestive of parapharyngeal hemangiopericytoma. The adjoining submandibular and the parotid glands were free of the tumor.

The patient was subsequently planned for adjuvant radiotherapy to the tumor bed. He received a total dose of 45 Gy in 20 fractions at 2.25 Gy per fraction, over four weeks, by six Mega-voltage photons. The patient is on regular follow-up for the last 20 months without any evidence of disease recurrence.

Hemangiopericytoma is a rare mesenchymal tumor originating from the pericyte of Zimmeran surrounding the capillaries and postcapillary venules. The head and neck are common sites, but hemangiopericytoma of parapharyngeal space is rare and only few cases have been reported to date. [1],[2] It is a firm, painless, and slowly expanding mass of vascular origin. Plain radiography is nonspecific; however, it has certain characteristic features on angiography. This includes hypervascularity, radially arranged branching vessels around and inside the tumor, and longstanding, well-demarcated tumor stains. [3] Angiography is therefore recommended for confirmation of diagnosis of vascular neoplasm, preoperative definition of blood supply, and embolization of tumor.

Magnetic Resonance Imaging (MRI) provides useful preoperative information about the extent of the tumor and its relationship to the surrounding structures and distinguishes between intraparotid and extra-parotid neoplasms. [4] Computerized tomography is helpful in the evaluation of bony erosions. Complete surgical resection, if possible, combined with preoperative embolization is the initial treatment of choice. [5] Extensive surgery is required in tumors that show features of malignancy. Long-term follow-up is necessary even after radical surgery because late recurrences and metastases have been reported. Radiotherapy was previously used for sterilization of the tumor bed in an adjuvant setting, by eradicating the microscopic / subclinical disease. However, its use is now primarily confined to treating residual and recurrent or unresectable disease.[1] Commonly prescribed schedules are 50 Gy in 25 fractions and 45 Gy in 20 fractions. The role of chemotherapy is ill-defined. Adriamycin alone or in combination, is the most effective drug for metastatic hemangiopericytoma, having produced responses in 50% of the cases.

References

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2Llorente JL, Suárez C, Ablanedo P, Carreño M, Alvarez JC, Rodrigo JP. Hemangiopericytoma of the parapharyngeal space. Otolaryngol Head Neck Surg 1999;120:531-3.
3Liu DG, Ma XC, Li BM, Zhang JG. Clinical study of preoperative angiography and embolization of hypervascular neoplasms in the oral and maxillofacial region. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:102-9.
4Stambuk HE, Patel SG. Imaging of the parapharyngeal space. Otolaryngol Clin North Am 2008;41:77-101.
5Walike JW, Bailey BJ. Head and neck hemangiopericytoma. Arch Otolaryngol 1971;93:1036-41.