The most common primary tumors of the lacrimal gland are pleomorphic adenoma and adenoid cystic carcinoma. Malignant mixed tumor is much less common.
Pleomorphic AdenomaPleomorphic adenoma (benign mixed tumor) accounts for about 50% of all epithelial lacrimal gland tumors. [28,
29,
30] Benign mixed tumor may occur at any age (mean is 39 years). A painless mass in the lacrimal fossa is often observed. By CT scan, the tumors are globular in shape and may indent sclera and remodeled bone. It has been demonstrated that open biopsy of both major salivary and lacrimal gland benign mixed tumors may lead to seeding. [31] No cases of seeding have been documented following fine needle aspiration biopsy of these tumors from salivary glands. [
32,
33] No cases of fine needle aspiration of lacrimal gland mixed tumor have been reported. Fine needle aspiration of mixed tumors shows tightly clustered benign epithelial cells and characteristic mucinous chondroid matrix (Figure 10-12).
Adenoid Cystic CarcinomaAdenoid cystic carcinoma accounts for about 25% to 30% of all epithelial lacrimal gland tumors. [34,
35] Clinically, the patients usually have symptoms of pain and develop a mass in the lacrimal fossa (Figure 10-13). On CT scan, adenoid cystic carcinomas are globular tumors, but frequently have irregular destructive margins around orbital bones (Figure 10-14). [36] Fine needle aspiration shows numerous clusters and single cells. The cells form characteristic rosettes that surround magenta basement membrane material (Figure 10-15). This material does not stain with hematoxylin and eosin or Papanicolaou stain. Occasionally, mitotic figures and individual cell necrosis can be seen. This pattern correlates well with basement membrane material seen in the center of cribiform areas on histologic sections (Figure 10-16). The correlation of prognosis of adenoid cystic carcinoma with the histologic patterns is controversial. [
37,
38]The treatment for these lesions is also controversial and ranges from excision of the tumor with radiation, en bloc excision with resection of contiguous bone, orbital exenteration, and radical orbitectomy. [
39,
40] At present, there is not enough follow-up data to demonstrate that radical procedures result in cure.