Benign stromal fragments in metastases of squamous cell carcinoma in cytology--a report of two cases.

Benign stromal fragments or extracellular matrix can be seen in aspirates of invasive carcinomas. Although well documented on histology, this feature is rarely observed on fine needle aspirates and can create diagnostic difficulties on smears. Only three such cases have been reported so far. We report two more cases where stromal fragments were seen in association with invasive squamous cell carcinoma (SCC). Two cases of biopsy proved invasive SCC of the cheek and of the larynx presented with metastases to the submandibular salivary gland and to the cervical lymph node respectively. Aspirates of the metastatic sites showed two components: one of SCC and the other benign stroma, both in close approximation with one another. Both patients were treated with radiotherapy. Biopsy of the metastatic sites was not done. Benign stromal fragments can be encountered in aspirates of invasive carcinoma. These may be cellular or myxoid. Since such stromal fragments can also be seen in salivary tumours, adnexal tumours, fibroadenoma and phylloides tumour, their presence should be interpreted in the light of clinical findings of the patient, so that an erroneous diagnosis can be avoided.