PMA -Pleomorphic adenoma, FNAC - Fine needle aspiration
biopsy, ACC -Adeniod cystic carcinoma, RT -Radiotherapy,NM - Not Mentioned, NAD -No abnormality detected.
The present tumor was also, provisionally described as a
lymphoepithelial cyst or Warthins tumor on the CECT examination.
Predicting a benign neoplasm with negligible metastatic potential, the
case was surgically managed by a minimally invasive option of
superficial parotidectomy with facial nerve preservation. The pathology
was disparate from the pre-operative diagnosis and reported as the rare
polymorphous low-grade adenocarcinoma of the parotid gland. It was
concluded to be the classical variant as per the WHO 2017 classification
due to clinical evidence of slow growth with the absence of local or
distant metastasis over the last 10 years and the presence of small to
medium cells in multiple patterns, targetoid cells, and <30 %
of cribriform areas.4 It was further confirmed by the
diffuse positivity for the S-100 stain, which is reported to be
associated with more than 90 % of reported cases.16
The recommended treatment of PLGA, independent of its location, consists
of the wide local surgical excision, and neck dissection should be added
only in cases with cervical lymphadenopathy.17 The
complete surgical excision of the parotid gland was not accomplished for
the present case as the initial treatment plan was framed, considering
it a benign lesion. The role of postoperative radiotherapy is ambiguous
in the treatment of PLGA. It may diminish the local recurrence of tumors
having high-risk features, closed margins, perineural invasion, etc
[6]. However, the recurrence might take years to develop in PLGAs
without adverse features with negative or even positive
margins.6,17 The main limitation of the present case
is the non-accomplishment of radiotherapy due to the patient’s denial.
As the tumor was a classical variant suspected to have an indolent
course and the postoperative CT scan also recorded minimal residual
disease, he is kept under the regular three-month follow-up to detect
the earliest sign of any anticipated complications.
CONCLUSION AND RESULTS
PLGA of the parotid gland is a rare entity in the Asian population with
diverse morphology and cytological patterns. The available pre-operative
investigations have a limited role in its diagnosis, and a detailed
histopathological examination is the standard for confirmation.
AUTHOR CONTRIBUTION: IPK, PD, MS Conceptualization; data
curation; resources; software; writing – original draft; writing –
review and editing. VP, AM, JS, NS Conceptualization; formal
analysis; supervision; writing – original draft; writing – review and
editing. All authors agreed to the final version of the manuscript.