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| Year : 2016 | Volume
: 59
| Issue : 4 | Page : 559-560 |
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| Primary synovial sarcoma of the parotid gland: An unusual entity |
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Abhimanyu Sharma1, Mayurika Tyagi1, Sanjay Gupta2, Vinod Kumar Arora1
1 Department of Pathology, University College of Medical Sciences and Guru Tegh Bahadur Hospital, New Delhi, India
2 Department of Surgery, University College of Medical Sciences and Guru Tegh Bahadur Hospital, New Delhi, India
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| Date of Web Publication | 10-Oct-2016 |
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How to cite this article:
Sharma A, Tyagi M, Gupta S, Arora VK. Primary synovial sarcoma of the parotid gland: An unusual entity. Indian J Pathol Microbiol 2016;59:559-60 |
Editor,
Mesenchymal tumors of the parotid gland account for <5% of the primary tumors of the parotid, the most common being hemangiomas. [1] Sarcomas of the parotid gland are rare, accounting for 0.3%-1.5% of the primary tumors of the parotid. [2] Synovial sarcomas are known to occur in the head and neck region but mainly in the paravertebral region. [3]
A 55-year-old female presented to us with complaints of swelling in the left parotid region for 1 year. On examination, swelling was noted in the left parotid region with tense irregular surface, soft to firm consistency with mildly erythematous overlying skin. Computed tomography scan revealed a well-defined heterodense mass lesion with lobulated irregular margins, involving the superficial and deep lobe of left parotid gland. In addition, multiple-enhancing septae were noted with hypodense areas suggestive of necrosis. The lesion was seen infiltrating the left sternocleidomastoid muscle and encasing the left external jugular vein.
Fine-needle aspiration cytology was suggestive of spindle cell mesenchymal tumor. A marginal resection specimen of parotid was received with a firm to hard tumor measuring 7 cm × 6 cm × 6 cm with recognizable salivary tissue at the periphery. On cut surface, the tumor was solid, lobulated, gray-white in color with glistening areas [Figure 1]a and b. Microscopically, oval to spindle shaped tumor cells were arranged in the form of sheets and fascicles in a myxoid background [Figure 1]c and d. The cells had moderate amount of indistinct cytoplasm, round to oval nucleus with prominent nucleoli. The tumor cells showed pleomorphism with the presence of numerous bizarre cells. Tumor giant cells and areas of necrosis (<50%) were also noted [Figure 2]a and b. Mitotic rate was 2-3/10 high power fields. On immunohistochemistry (IHC), the tumor cells were strongly positive for epithelial membrane antigen and vimentin [Figure 2]c and d. Tumor was negative for pancytokeratin. Based on the above findings, a diagnosis of synovial sarcoma of the parotid gland was rendered. The patient further received radiotherapy and has been on follow-up for 1 year with no signs of recurrence. | Figure 1: Synovial sarcoma of parotid: Gross and microscopic findings. (a) Gross specimen: Tumor showing glistening, gray-white and solid areas. (b) Tumor surrounded by lobules of salivary gland (H and E, ×40). (c) Tumor showing large areas of myxoid change (H and E, ×100). (d) Higher magnification showing myxoid degeneration (H and E, ×200)
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 | Figure 2: Synovial sarcoma, microscopy: H and E and immunohistochemistry. (a) Tumor showing highly pleomorphic cells (H and E, ×200). (b) Tumor showing storiform pattern (H and E, ×200). (c) Epithelial membrane antigen (IHC, ×400). (d) Vimentin (IHC, ×200)
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This case fulfills the basic criteria established by Luna et al. for diagnosis of primary sarcoma of the salivary gland. [2] These are:
- The patient must not have a sarcoma elsewhere
- Metastasis should be excluded
- The gross and microscopic appearance should be consistent with origin within the gland, rather than invasion of the gland by sarcoma of adjacent soft tissues
- Within the limit of microscopic study of multiple sections, a carcinosarcoma must be excluded.
Our case had a monophasic spindle cell pattern with the absence of epithelial-like elements. Large areas of myxoid change were present throughout the tumor. Myxoid areas can be seen in a variety of sarcomas including fibrosarcoma, liposarcoma, undifferentiated sarcoma, synovial sarcoma, etc., It is important to differentiate between the above entities as treatment, and prognostic considerations are different. We used morphological considerations and IHC to reach a final diagnosis. This case shows that although uncommon, synovial sarcomas do occur in the parotid and should be recognized for proper management.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
 References | |  |
| 1. | Rigante M, Visocchi M, Petrone G, Mulè A, Bussu F. Synovial sarcoma of the parotid gland: A case report and review of the literature. Acta Otorhinolaryngol Ital 2011;31:43-6.  |
| 2. | Luna MA, Tortoledo ME, Ordóñez NG, Frankenthaler RA, Batsakis JG. Primary sarcomas of the major salivary glands. Arch Otolaryngol Head Neck Surg 1991;117:302-6. |
| 3. | Weiss SW, Goldblum JR. Synovial sarcoma. In: Enzinger and Weiss's Soft Tissue Tumours. 5 th ed. Philadelphia: Elsevier; 2008. p. 1161-81. |
Correspondence Address:
Vinod Kumar Arora
Department of Pathology, University College of Medical Sciences and Guru Tegh Bahadur Hospital, New Delhi - 110 095
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0377-4929.191768
[Figure 1], [Figure 2] |
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