Conjunctival leiomyosarcoma: A case report and review of literature

Conjunctival leiomyosarcoma: A clinico-pathological study with in deep molecular characterization

BACKGROUND

Primary and metastatic leiomyosarcomas (LMS) involving the orbital region are well known to occur however, the conjunctiva represents an extremely rare site of occurrence.

METHODS

A 97-year-old male was referred to the Ocular Oncology Unit due to a rapidly growing painful mass (16×12×20 mm) in the nasal conjunctiva of his left eye. Wide excision followed by radiotherapy was performed.

RESULTS

Based on the microscopic features (hypercellular neoplasm composed of spindle cells with cigar shaped and blunt ended nuclei with brightly eosinophilic fibrillary cytoplasm) and immunohistochemical findings (positive staining for Vimentin, Desmin, Caldesmon, and SMA and negative staining for AE1/AE3, EMA, CD117, S100, MelanA, SOX10, HMB45, TLE1, CD99, EMA and AE1 / AE3) the final diagnosis of grade 2 leyomiosarcoma was rendered. Moreover, 'in deep' DNA sequencing (>500 genes analysis) revealed a neoplasm with high TMB: 64 muts/Mb and numerous VUS and several pathogenic/oncogenic molecular alterations, including CNV loss or gain in > 10 genes. At the last follow-up visit, residual disease was observed in the superior fornix, at the nasal limbus and the cornea. At the time of writing, after a follow-up of 2 month the patients is still alive without evidence of metastatic disease.

CONCLUSION

An uncommon molecular finding observed in our case was the presence of TSC1 gene mutation usually associated with soft tissue and gynecological PEComas. Our finding may harbor important therapeutic implications since the inactivation of the tumor suppressor genes TSC1 and TSC2 lead to upregulation of mTOR signaling, providing the rationale for target therapy with mTOR inhibitors. Additional studies on larger series are needed to validate our findings.

Conjunctival Leiomyosarcoma, a Rare Neoplasm Always Originating at the Limbus? Report of a New Case and Review of 11 Published Cases

PURPOSE OF THE STUDY

To describe the differential diagnosis and management of a rare conjunctival malignancy.

PROCEDURES

A 79-year-old man presented with a conjunctival mass at the limbus. Excisional biopsy revealed a malignant mesenchymal tumor with myogenic differentiation. Six months later, three suspect lesions developed at the border of the previous excision. Pathological diagnosis pointed to a leiomyosarcoma. Adjuvant radiotherapy with strontium-90 brachytherapy was applied. After 3 years, there was neither recurrence nor distant metastases. A literature review revealed 11 cases of conjunctival leiomyosarcoma.

RESULTS

All 12 cases seemed to originate at the limbal conjunctiva. Scleral invasion was found only in one patient with multiple previous resections. Corneal invasion was reported in two patients. Four patients had a globe-sparing resection. In two of them, margins were not tumor free and additional brachytherapy gave a tumor-free follow-up of 1 and 3 years. Four cases underwent an exenteration.

CONCLUSION AND MESSAGE

Primary conjunctival leiomyosarcoma is a rare tumor with a favorable prognosis due to early detection and consequently limited size. Diagnosis involves histopathological investigation including immunohistochemistry. If possible, complete resection has the best prognosis. Adjunctive radiotherapy can be effective when the margins are not free and should be considered.