Carcinoma Ex Pleomorphic Adenoma
Pronunciation: kar-sih-NOH-mah ex plee-oh-MOR-fik ad-eh-NOH-mah
A malignant salivary gland tumour arising from within a pre-existing or recurrent pleomorphic adenoma, classified by the extent of invasive carcinoma into non-invasive, minimally invasive, and invasive subtypes.
Full Definition
Carcinoma ex pleomorphic adenoma (Ca-ex-PA) is a malignant transformation occurring within a pleomorphic adenoma (PA) and represents approximately 3–15% of all parotid malignancies. The diagnosis requires histological identification of both a residual benign PA component and a frank carcinomatous element. WHO classification distinguishes three invasive subtypes based on carcinoma extension beyond the PA capsule: non-invasive (intracapsular), minimally invasive (≤1.5 mm beyond the capsule), and widely invasive (>1.5 mm), each with different prognoses. Editors must retain the preposition 'ex' (Latin: out of) and ensure it is not dropped or replaced by 'in' or 'from.' The abbreviation 'Ca-ex-PA' is acceptable after definition. Long-standing untreated PAs are a known risk factor, making accurate clinical history documentation critical.
Usage
Usage note: The Latin preposition 'ex' is an integral part of this diagnostic term and must be retained. Do not italicise 'ex' in running text unless following a style that italicises all Latin terms.
In Context
- "The resection specimen confirmed a widely invasive carcinoma ex pleomorphic adenoma with clear evidence of capsular breach extending 4 mm into the surrounding parotid parenchyma." — Surgical pathology report
- "The preposition 'ex' in 'carcinoma ex pleomorphic adenoma' must not be omitted or replaced; it is part of the established diagnostic term." — Editorial style note for oncology reports