Primary leiomyosarcoma of the maxilla: An investigative loom-report of a challenging case and review of literature

Abstract

Leiomyosarcoma (LMS) is a malignant neoplasm composed of cells showing distinct smooth muscle features. Majority of the tumors are located in the retroperitoneum, including the pelvis and the uterus but are rare in the oral and pharyngeal region. Intraorally, they are present as painless, lobulated, fixed masses of the submucosal tissues in middle-aged or older individuals. Lesions are usually slow growing and are less than 2 cm in diameter at the time of diagnosis. Here we report the clinico-pathological findings of a case of primary LMS of the maxilla in 63-year-old male patient with an emphasis on the judicious use of ancillary diagnostic modalities to arrive at a definitive diagnosis.

Keywords: Leiomyosarcoma; malignant spindle cell tumor; nuclear palisading; pleomorphic undifferentiated sarcoma; rhabdomyosarcoma; soft tissue sarcoma.

Figure 1

(a) Intraoral photograph showing bosselated growth in the anterior maxilla with patchy bluish discoloration extending from right canine to left lateral incisor with palatal extension in the anteroposterior direction involving the midline. (b) Computed tomography (CT) axial section showing a diffuse soft tissue mass obliterating the anterior nasal chamber. The lesion is also seen extending in the anterior maxillary alveolus area completely destroying the anatomy of the anterior palate and the nasal cartilaginous skeleton

Figure 2

Gross appearance of the excised dentate hemimaxilla. The tumor mass measured 8 cm × 7.5 cm in dimensions and was creamish brown in color with color variegation ranging from brown to yellow and was firm in consistency

Figure 3

Photomicrographs showing a) Low power view of a tumor mass with numerous engorged vascular channels (H&E stain, x40). (b) Tumor mass composed of fascicles of interlacing spindle-shaped cells with abundant eosinophilic cytoplasm and moderately large nuclei exhibiting atypia (H&E stain, ×40). (c) Elongated cells with abundant cytoplasm exhibiting centrally placed blunt ended nuclei (H&E stain, ×100). (d) Bizarre tumor cells with nuclear pleomorphism interspersed among regular spindle-shaped cells (H&E stain, ×100)

Figure 4

Photomicrographs showing pleomorphism in leiomyosarcoma. (a) Bizarre spindle cell exhibiting deeply eosinophilic cytoplasm with pleomorphic nuclei and nuclear vacuolization (H&E stain, ×400). (b) Cells exhibiting extreme degree of pleomorphism and occasional multinucleation resembling pleomorphic undifferentiated sarcoma/ malignant fibrous histiocytoma (H&E stain, ×400)

Figure 5

Photomicrographs showing (a) Strong positive immunohistochemical reaction to antibodies against vimentin (IHC stain, ×100), (b) Focal expression of smooth muscle actin (SMA) in the tumour cells (IHC stain, ×100), (c) Focal reaction to muscle specific actin (HHF-35) by the tumor cells (IHC stain, ×400)