Cribriform adenocarcinoma of the base of the tongue and low-grade, polymorphic adenocarcinomas of the salivary glands

Abstract

Low-grade, polymorphic adenocarcinomas occur mainly in females and are usually associated with the small salivary glands of the palate. The tumors are malignant, but not aggressive. Regional neck as well as distant metastasis is rare and the mortality rate is low. Cribriform adenocarcinoma of the salivary glands is a rare tumor, currently ranked among low-grade, polymorphic adenocarcinomas of the salivary glands. However, it differs from carcinomas in this group as it metastasizes to the cervical lymph nodes and exhibits frequent primary localization in the small salivary glands at the base of the tongue. Despite the tendency to metastasize, patient prognosis remains favorable. A case of a 72-year-old woman with neck metastases of cribriform adenocarcinoma, of unknown primary origin, is reported. The primary tumor origin was ultimately determined using nuclear magnetic resonance, histological verification was difficult due to the presence of an intact mucosal cover over the tumor. Cribriform adenocarcinoma is known to have a number of characteristics in common with a typical low-grade, salivary gland adenocarcinoma. However, in contrast to low-grade adenocarcinomas, the tumor presented with neck lymph node metastasis.

Figure 1

Nuclear magnetic resonance scan of the base of the tongue. Poorly-differentiable infiltration is visible at the base of the right half of the tongue.

Figure 2

Cribriform arrangement of the tumor. Paraffin section, H&E stain, magnification, ×125.

Figure 3

High positivity for the S100 protein. Paraffin section, magnification, ×125.

Figure 4

High positivity for the epithelial marker cytokeratin CK7. Paraffin section, magnification, ×125.

Figure 5

Proliferative marker MIB 1 (Ki-67). Paraffin section, magnification, ×125.

Figure 6

Negativity for actin. Paraffin section, magnification, ×125.

Figure 7

Histology of the neck lymph node metastases. Paraffin section, H&E stain, magnification, ×125.

Figure 8

Intact epithelial surface of the base of tongue. Paraffin section, H&E stain, magnification, ×12.5.