Like pulmonary small cell carcinoma, the tumor is composed of ovoid to round loosely packed blue cells with scant cytoplasm infiltrating diffusely into the parenchyma.
Background fibrous stroma is also present, separating tumor cells. Cytologically the cells show finely dispersed but hyperchromatic chromatin and inconspicuous nucleoli.
Within the category of extrapulmonary small cell carcinoma, salivary small cell carcinoma is a rare lesion accounting for less than 2% of salivary gland malignancies1 .
Usually 5th-7th decade, with M:F ratio of 6:1. Tumors present as a nonpainful parotid mass of short (a few months) duration. Lymphadenopathy and facial nerve palsy are often present at the time of diagnosis as well2 . Metastatic disease from other extrapulmonary small cell carcinoma to the salivary gland is rare but may be of concern in cases presenting with widespread metastasis.
Optimal treatment strategies are undefined, owing to the rarity of this tumor. Treatment typically consists of total or comprehensive parotidectomy with facial nerve sacrifice in cases of preoperative dysfunction or encasement. Postoperative radiation therapy and neoadjuvant/adjuvant chemotherapy use are reported in the literature, however, their routine role in disease management has yet to be established8 .
About half of patients with salivary small cell carcinoma will develop recurrence or metastasis, with hematogenous spread seen more commonly than lymphatic mets. 5-year survival rates for tumors in the major glands range from 15 to 50%3,4,5 .
1 Ellis GL, Auclair PL (1996). Tumours of the salivary glands. 3rd ed. Armed Forces
Institute of Pathology: Washington. 669. Ellis GL, Auclair PL, Gnepp DR
2 Mineta H, Miura K, Takebayashi S, Araki K, Ueda Y, Harada H, Misawa K (2001). Immunohistochemical analysis of small cell carcinoma of the head and neck: a report of four patients and a review of sixteen patients in the literature with ectopic hormone production. Ann Otol Rhinol Laryngol 110: 76-82.
3 Gnepp DR, Corio RL, Brannon RB (1986). Small cell carcinoma of the major
salivary glands. Cancer 58: 705-714.
4 Nagao T, Gaffey TA, Olsen KD, Serizawa H, Lewis JE (2004). Small cell carcinoma
of the major salivary glands: clinicopathologic study with emphasis on cytokeratin 20 immunoreactivity and clinical outcome. Am J Surg Pathol 28: 762-770.
5 Pierce ST, Cibull ML, Metcalfe MS, Sloan D (1994). Bone marrow metastases from small cell cancer of the head and neck. Head Neck 16: 266-271.
6 Small cell carcinoma of the major salivary glands. Gnepp DR, Corio RL, Brannon RB. Cancer. 1986 Aug 1;58(3):705-14.
7 Kaira K, Shimizu Y, Tsuchiya T, Mizuide M, Hisada T, Ishizuka T, Mori M. Small cell carcinoma of the parotid gland. Otolaryngol Head Neck Surg. 2007 Feb;136(2):330-1.
8 R.M. Levenson Jr, D.C. Ihde and M.J. Matthews et al., Small cell carcinoma presenting as an extrapulmonary neoplasm: sites of origin and response to chemotherapy, J Natl Cancer Inst 67 (1981), pp. 607–612