Case report:
A 55 years male presented to the head and neck oncology department with complaints of swelling in the left lateral border of the tongue for the last four yearsalongwith a cytotopathology report of FNAC suggesting the diagnosis of Pleomorphic Adenoma. To begin with, the swelling initiated as asmall nodule which gradually increased to its present size over the period of four years. There was no history of trauma, pain, burning sensation, difficulty in swallowing,and change in speech quality.There was no significant past and family history.
The vitals were normal at the time of arrival. On examination, there was a firm nodular swelling of 2 x 1.5 cm size located in the left lateral border of the tongue with normal mucosa (fig.1). There was no ulceration and no signs of inflammation over the swelling. Similarly, lymph nodes were not palpable in the neck.
Magnetic Resonance Imaging (MRI) of the tongue was ordered that showed a well-defined, oval-shaped, soft tissue lesion within the tongue on the left side (fig. 2a, 2b). This post-gadolinium-enhanced lesion measured about 18 x 19 mm in size and was seen about 19 mm distal to the tip of the tongue (fig. 2c). No evidence of restricted diffusion wasnoted. The lesion was seen extending to the distal edge of the tongue with no evidence of extension across the midline, into the surrounding tissue and overlying teeth and bone. Additionally, multiple small lymph nodes were visible in levels I (IA right side 9 x 13mm), II (IIA right side 10 x 12 mm), and III (9 x 10 mm right side) of the neck bilaterally.
The patient was admitted to the hospital and scheduled for elective surgery for the removal of the lesion. The pre-anesthetic evaluation revealed normal vitals and examination findings. All hematology (Complete Blood Count, Prothrombin Time), biochemistry (Liver function Test, Renal Function Test) and serology (for HIV, Hepatitis B and Hepatitis C) were normal. A real-time RT-PCR was negative for SARS CoV 2.The patient underwent a left partial glossectomyto remove the lesion under general anesthesia.Intra-operative and postoperative periods were uneventful. Post-operatively patient was managed conservatively.
On gross examination, specimen of size 5 x 3.4 x 2.5 cm was received (fig. 3). It was well-circumscribed, grey-white, tanned solid mass with unremarkable mucosal findings. The tumor was unifocal and located at the left lateral border of the tongue with a size of 2.3 x 2 x 2.2 cm. Grossly, all mucosal, soft tissue, and deep margins (anterior, posterior, lateral, medial, superior, inferior, and deep) were uninvolved by the tumor. The distance from the closest mucosal margin was 0.7 cm (anterior), and from the deep margin was 0.2 cm.
Under microscopy, the sections showed sub-mucosal circumscribed nodular lesion composed of clear cells of variable size arranged in sheets (fig. 4a). These cells had eccentric nuclei with abundant vacuolated clear cytoplasm suggesting the diagnosis of clear cell neoplasm, which contradicted the initial diagnosis of pleomorphic adenoma (fig. 4b, 4c). No necrosis, increased mitosis, and atypia were appreciated.But thin-walled capillaries were observed between these clear cells. Further evaluation by immunohistochemistry showed positivity for S100, CDK4, MDM2 (fig. 5a, 5b, 5c) with 2% Ki-67 but negativity for CK favoring the histomorphological diagnosis of well differentiated liposarcoma.
On discharge, the patient washaemodynamically stable, and his wound was healing well. The post disease status of the patient was evaluated after the diagnosis of well-differentiated liposarcoma by F18 FDG PET CT Scan, which was within the normal limit.