Polymorphous low-grade adenocarcinoma of the upper lip: 11 cases of an uncommon diagnosis.
OBJECTIVE
The aim of this case study was to describe an international case series of polymorphous low-grade adenocarcinoma (PLGA) affecting the upper lip.


METHODS
Over a 30-year-period, the files of five pathology services were reviewed for PLGA affecting the upper lip. Hematoxylin and eosin-stained slides were reviewed by three oral and maxillofacial pathologists, and microscopic features were described. Clinical data were retrieved from patients' medical records.


RESULTS
The review identified 11 cases of upper lip PLGAs, with a complete set of clinical data available for 5 cases. There was a male predominance (1.2:1), and the mean age was 58.7 years. Most cases presented as small asymptomatic swellings that resembled benign tumors. All patients underwent surgery, and no recurrences or metastases were reported in the 8 cases from which follow-up data were available. Microscopically, the typical polymorphic architectural arrangement of PLGA was seen in all cases, with lobular, trabecular, papillary, and cribriform patterns identified. Perineural invasion, normal gland entrapment, Indian filing, and concentric growth were frequently identified.


CONCLUSIONS
PLGA must be included in the list of differential diagnoses of tumors affecting the upper lip because of its similar clinical presentation to benign entities. The follow-up data available from 8 of 11 cases suggest that these tumors follow a low-grade clinical course, similar to the majority of palatal cases of PLGA.
Oral Diagnosis Department (Pathology and Semiology), Piracicaba Dental School, University of Campinas, Brazil.
Felipe Paiva
FP
Fonseca
Academic Unit of Oral and Maxillofacial Pathology, School of Clinical Dentistry, The University of Sheffield, UK.
Daniel
D
Brierley
Department of Diagnostic Sciences, Texas A&M University Baylor College of Dentistry, Dallas, Texas, USA.
John M
JM
Wright
Oral Diagnosis Department (Pathology and Semiology), Piracicaba Dental School, University of Campinas, Brazil.
Alan Roger
AR
Santos-Silva
Oral Diagnosis Department (Pathology and Semiology), Piracicaba Dental School, University of Campinas, Brazil.
Oslei Paes
OP
Almeida
Oral and Maxillofacial Surgery and Traumatology Service, Clinical Hospital, Medical School, University of São Paulo, Brazil.
André Caroli
AC
Rocha
Department of Oral Pathology and Oral Biology, School of Dentistry - Faculty of Health Sciences, University of Pretoria, South Africa.
Willie F
WF
Van Heerden
Academic Unit of Oral and Maxillofacial Pathology, School of Clinical Dentistry, The University of Sheffield, UK; Department of Oral Pathology and Oral Biology, School of Dentistry - Faculty of Health Sciences, University of Pretoria, South Africa. Electronic address: k.hunter@sheffield.ac.uk.
Keith D
KD
Hunter
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008048:Lip Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D012189:Retrospective Studies