Leiomyosarcoma (LMS) is a malignant mesenchymal neoplasm with frequent local recurrences and distant metastases composed of cells showing smooth muscle differentiation [1]. LMSs can arise from several anatomic sites the most common being the extremities (mainly lower extremities), retroperitoneum, abdominal-pelvic region, uterus, large blood vessels and trunk [2], [3], [4]. This neoplasm shows a peak incidence in the seventh decade of life however, young adults and children can also be affected [1], [2], [3], [4]. Histologically, LMS is characterized by a proliferation of spindle-shaped cells set in long intersecting fascicles [1], [5], [6]. Moderate to severe nuclear pleomorphism and epithelioid morphology may also be observed [1], [5], [6]. Neoplastic cells show moderate to abundant, pale to eosinophilic cytoplasm and plump, blunt-ended nuclei; mitotic figures are usually easily identifiable [1]. The most frequently observed stromal changes include fibrosis, myxoid areas, and hyalinized hypocellular areas [1], [5], [6]. By immunohistochemistry, neoplastic cells show positive stain for at least one myogenic marker (SMA, desmin, h-caldesmon) with the majority of cases being positive for more than one of these markers [1], [7], [8], [9]. Primary and metastatic leiomyosarcomas involving the orbital region are well known to occur however, the conjunctiva represents an extremely rare site of occurrence with only 13 cases reported in the literature so far [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21].

We herein report an additional rare case of conjunctival LMS arising in a 97-year-old male. Surprisingly, sequencing analysis revealed multiple genomic alterations including TSC1 gene mutation, which is traditionally associated with PEC-omas [22]. Clinico-pathological features as well as molecular findings are herein discussed.