Amrita Ghosh1, Anupam Kumar Asthana. 1. Department of Pathology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India. amrita_lko@rediffmail.com
Abstract
BACKGROUND: Metastasizing pleomorphic adenoma (MPA) is a rare, incompletely understood enigmatic entity having the histologic appearance of benign pleomorphic adenoma and clinically malignant behavior. We report a case of MPA of the parotid gland that metastasized to the scapular region 6 years after the appearance of the primary lesion in the left parotid gland. CASE: A 35-year-old woman presented with a palpable soft to firm mass of 3-cm diameter in the left scapular region that was slightly mobile over the underlying structures and a small swelling at the operated site of the parotid region. The patient had a prior history of surgical removal of recurrent pleomorphic adenoma of the left parotid salivary gland. Fine needle aspiration cytology (FNAC) smears of both sites demonstrated the 3 components (i.e., stromal, mesenchymal and epithelial) of benign pleomorphic adenoma with benign features. The diagnosis was MPA. CONCLUSION: The appearance of a mass lesion or subcutaneous nodule with a prior history of pleomorphic adenoma should alert for the possibilities of metastatic carcinoma, metastatic carcinosarcoma and MPA. With well-established cytomorphology of pleomorphic adenoma, FNAC remains the investigation method of choice for metastatic workup of a case of locally recurrent pleomorphic adenoma.
BACKGROUND:Metastasizing pleomorphic adenoma (MPA) is a rare, incompletely understood enigmatic entity having the histologic appearance of benign pleomorphic adenoma and clinically malignant behavior. We report a case of MPA of the parotid gland that metastasized to the scapular region 6 years after the appearance of the primary lesion in the left parotid gland. CASE: A 35-year-old woman presented with a palpable soft to firm mass of 3-cm diameter in the left scapular region that was slightly mobile over the underlying structures and a small swelling at the operated site of the parotid region. The patient had a prior history of surgical removal of recurrent pleomorphic adenoma of the left parotid salivary gland. Fine needle aspiration cytology (FNAC) smears of both sites demonstrated the 3 components (i.e., stromal, mesenchymal and epithelial) of benign pleomorphic adenoma with benign features. The diagnosis was MPA. CONCLUSION: The appearance of a mass lesion or subcutaneous nodule with a prior history of pleomorphic adenoma should alert for the possibilities of metastatic carcinoma, metastatic carcinosarcoma and MPA. With well-established cytomorphology of pleomorphic adenoma, FNAC remains the investigation method of choice for metastatic workup of a case of locally recurrent pleomorphic adenoma.