Polymorphous adenocarcinoma
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Polymorphous adenocarcinoma, abbreviated PAC, is a rare malignant salivary gland tumour.
| Polymorphous adenocarcinoma | |
|---|---|
| Diagnosis in short | |
 Polymorphous adenocarcinoma. H&E stain. | |
|
| |
| Synonyms | polymorphmous low-grade adenocarcinoma (obsolete term) |
|
| |
| LM | low-grade cytology - nuclei ovoid & small, small nucleoli, powdery chromatin (papillary thyroid carcinoma-like appearance); eosinophilic cytoplasm; variable architecture - often small nests, classically has whorling ("eye-of-storm") pattern and single file pattern |
| LM DDx | adenoid cystic carcinoma, pleomorphic adenoma, cribriform adenocarcinoma of the minor salivary gland |
| IHC | S-100 +ve, CK7 +ve, p40 -ve, p63 +ve, vimentin +ve |
| Site | oral cavity, salivary gland |
|
| |
| Prevalence | uncommon (varies by study) |
| Prognosis | good |
It was previously known as polymorphous low-grade adenocarcinoma, abbreviated PLGA.[1]
General
Gross
- Tumour of the minor salivary glands.[5]
- Almost exclusively in the oral cavity - usually palate.[3]
Microscopic
Features:[6]
- Architecture: often small nests, may be targetoid.
- Classically has whorling with eye-of-storm & single file.
- Cytologically monotonous (uniform) with variable architecture - key feature.
- Nucleus: ovoid & small, small nucleoli, powdery chromatin.
- Papillary thyroid carcinoma-like appearance.
- Cytoplasm: eosinophilic.
- Nucleus: ovoid & small, small nucleoli, powdery chromatin.
- Indistinct cell borders.
Note:
- Pretty much always a low-grade tumour.
DDx:
- Adenoid cystic carcinoma.
- Pleomorphic adenoma.
- Cribriform adenocarcinoma of the minor salivary gland - if one considers it a separate diagnosis.
- The World Health Organization lumps cribriform adenocarcinoma of the minor salivary gland with polymorphous adenocarcinoma.[1]
Images
PLGA - very low mag. (WC/Nephron)
PLGA - high mag. (WC/Nephron)
IHC
Features:[2]
- S-100 +ve.
- CK7 +ve.
- Vimentin +ve.
- p63 +ve (22 of 23 cases[7]).
- p40 -ve (22 of 23 cases[7]).
- Useful to differentiate from adenoid cystic carcinoma (AdCC); AdCC is usually p63 +ve/p40 +ve (36 or 47 cases) or p63 -ve/p40 -ve (10 of 47 cases).
- p63 +ve/p40 +ve is seen in pleomorphic adenoma and mucoepidermoid carcinoma (in addition to adenoid cystic carcinoma).[8]
Others:
- GFAP +ve/-ve.
- One study suggests GFAP cleanly separates the PLGA (-ve) from pleomorphic adenoma (+ve).[9]
- BCL2 +ve/-ve.
- Generally negative for myoepithelial markers (calponin, actin) - useful if negative.
See also
References
- ↑ 1.0 1.1 Vander Poorten V, Triantafyllou A, Skálová A, Stenman G, Bishop JA, Hauben E, Hunt JL, Hellquist H, Feys S, De Bree R, Mäkitie AA, Quer M, Strojan P, Guntinas-Lichius O, Rinaldo A, Ferlito A (July 2018). "Polymorphous adenocarcinoma of the salivary glands: reappraisal and update". Eur Arch Otorhinolaryngol 275 (7): 1681–1695. doi:10.1007/s00405-018-4985-5. PMID 29761209.
- ↑ 2.0 2.1 de Araujo, VC.; Passador-Santos, F.; Turssi, C.; Soares, AB.; de Araujo, NS. (2013). "Polymorphous low-grade adenocarcinoma: an analysis of epidemiological studies and hints for pathologists.". Diagn Pathol 8: 6. doi:10.1186/1746-1596-8-6. PMID 23320410.
- ↑ 3.0 3.1 Paleri, V.; Robinson, M.; Bradley, P. (Apr 2008). "Polymorphous low-grade adenocarcinoma of the head and neck.". Curr Opin Otolaryngol Head Neck Surg 16 (2): 163-9. doi:10.1097/MOO.0b013e3282f70441. PMID 18327037.
- ↑ Fife, TA.; Smith, B.; Sullivan, CA.; Browne, JD.; Waltonen, JD.. "Polymorphous low-grade adenocarcinoma: a 17 patient case series.". Am J Otolaryngol 34 (5): 445-8. doi:10.1016/j.amjoto.2013.03.012. PMID 23618791.
- ↑ Andreu-Barasoain, M.; Vicente-Martín, FJ.; Gómez de la Fuente, E.; Salamanca-Santamaría, J.; Pampín-Franco, A.; López-Estebaranz, JL. (2013). "Polymorphous low-grade adenocarcinoma in the upper lip: a well-described but infrequently recognized tumor.". Dermatol Online J 19 (8): 19265. PMID 24021444.
- ↑ Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 74. ISBN 978-0781765275.
- ↑ 7.0 7.1 Atiq A, Mushtaq S, Hassan U, Loya A, Hussain M, Akhter N (October 2019). "Utility of p63 and p40 in Distinguishing Polymorphous Adenocarcinoma and Adenoid Cystic Carcinoma". Asian Pac J Cancer Prev 20 (10): 2917–2921. doi:10.31557/APJCP.2019.20.10.2917. PMC 6982655. PMID 31653135. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6982655/.
- ↑ Sivakumar N, Narwal A, Pandiar D, Devi A, Anand R, Bansal D, Kamboj M (February 2022). "Diagnostic utility of p63/p40 in the histologic differentiation of salivary gland tumors: A systematic review". Oral Surg Oral Med Oral Pathol Oral Radiol 133 (2): 189–198. doi:10.1016/j.oooo.2021.07.010. PMID 34518135.
- ↑ Curran, AE.; White, DK.; Damm, DD.; Murrah, VA. (Feb 2001). "Polymorphous low-grade adenocarcinoma versus pleomorphic adenoma of minor salivary glands: resolution of a diagnostic dilemma by immunohistochemical analysis with glial fibrillary acidic protein.". Oral Surg Oral Med Oral Pathol Oral Radiol Endod 91 (2): 194-9. doi:10.1067/moe.2001.111306. PMID 11174597.