Primary Intracranial Leiomyosarcoma Involving the Frontal Sinus and Ethmoid Air Cells: Case Report and Literature Review

Objective: Sarcomas are generally rare tumors that arise from mesenchymal tissue, representing only 2% of all histologically confirmed tumors in adults, and most commonly present in soft tissue, retroperitoneum, and peritoneum. Central nervous system sarcomas are particularly unique. Leiomyosarcomas are a type of sarcoma that arise from smooth muscle and generally present in the abdomen. Although intracranial leiomyosarcomas have been identified before, most reported presentations have been in immunocompromised patients.

Methods and Results: A 22-year-old male with a history of an atypical pineal parenchymal tumor of intermediate differentiation resected by suboccipital craniotomy at age 12 followed by adjuvant radiation therapy, presented with three weeks of decreased appetite, weight loss, and lethargy. He subsequently underwent extensive tumor resection via bifrontal craniotomy with a skull base approach to the left orbit and ethmoid sinus for microsurgical resection.

Histologic examination of the mass revealed a spindle-cell neoplasm with fasciculated architecture and strong diffuse reactivity to caldesmon, supporting smooth vessel origins. Tumor specimen was negative for STAT-6 and e-cadherin staining. These findings, along with the patient's history of radiation, were supportive of a low-grade, radiation-induced leiomyosarcoma arising from the base of the skull or meninges.

Discussion: Primary intracranial leiomyosarcoma is an extremely rare diagnosis, thus current literature is limited. Presenting symptoms vary with location and size of the tumor with the most common symptoms of headache and vomiting. Diagnosis of intracranial leiomyosarcoma is difficult as it is very rare, resembles other malignancies, and requires histological and immunohistochemical analyses. Histologically, leiomyosarcomas consist of smooth muscle cells with cigar-shaped nuclei and malignant features such as atypia and mitotic figures. Clinical picture, microscopic evaluation, and diffuse staining for actin, desmin, and h-caldesmon support a diagnosis of leiomyosarcoma. Although variable treatment courses are reported in literature, surgical resection was the most common. Adjuvant chemotherapy with various agents have been found to be somewhat effective, complications with chemotherapeutic agents crossing the blood brain barrier limit which agents can be utilized. Directed therapies are also being designed. Prognosis is generally poor, depending on tumor size, location, and observed mitotic rate. Current literature reports survival ranging from 4 months to 44 months.

Conclusion: Leiomyosarcomas are rare tumors which seldom present in the CNS, therefore leading to a low index of suspicion in preoperative differential diagnosis. When leiomyosarcomas do occur, history of immunocompromised state or previous radiation exposure is often present. Pathological confirmation is required for an appropriate diagnosis. Microsurgical resection and adjuvant chemotherapy appear to be effective treatment modalities, however further research is necessary ([Figs. 1]–[4]).

Fig. 1 Preoperative T1 MRI with contrast.

Fig. 2 Illustration of operative steps.

Fig. 3 Postoperative T1 MRI with contrast.

Fig. 4 H&E stain of tumor tissue.

Publication History

Article published online:
15 February 2022