Giant Perivascular Epithelioid Cell Tumor of the Orbit: A Clinicopathological Analysis and Review of the Literature

An orbital perivascular epithelioid cell tumor (PEComa) in a 9-year-old boy: Case report and review of the literature

Perivascular epithelioid cell tumors (PEComas) are a family of benign neoplasms characterized by smooth muscle and melanocytic differentiation. Orbital cases are rare. A 9-year-old male presented with a slowly growing orbital mass. Magnetic resonance imaging (MRI) revealed a well-defined orbital mass without intracranial extension. The microscopic appearance of the complete resection specimen showed large nests of epithelioid cells with wide cytoplasm containing melanin pigment and round to oval nuclei with mild cytonuclear atypia and low mitotic activity. Immunohistochemistry was positive for HMB45 and negative for melanA, smooth muscle actin, desmin and S-100 protein. Pangenomic RNA-sequencing identified an in-frame NONO-TFE3 rearrangement, and clustering data showed that the tumor's gene expression profile was grouped with other previously studied PEComas. A diagnosis of orbital pigmented PEComa with uncertain malignant potential associated with a NONO-TFE3 rearrangement was made. There was no recurrence after 1 year of follow-up.

Perivascular epithelioid cell tumor of the lacrimal gland

A 33-year-old lady was referred to our clinic with a history of left upper eyelid swelling and difficulty to open her left eye for more than 4 years. Her globe was in infero-nasal displacement, and ocular movement was not full, with restriction to every direction. No clinical sign including eye redness, pain or visual loss was found on examination. Exophthalmometry confirmed 2 mm of left-sided proptosis. Computed tomography (CT) imaging of the orbit obtained in axial and coronal planes depicted an irregular and heterogeneous soft-tissue density mass in the left lacrimal gland, measuring 25 × 17 mm. Magnetic resonance imaging (MRI) revealed the mass of slightly longer T1 and slightly longer/shorter T2 signal, and Gd-enhanced MRI showed a significant enhancement. The tumor was first presumably diagnosed of pleomorphic adenomas. A surgery was applied to remove the tumor completely. Histopathological evaluation led to the diagnosis of PEComa.

Pediatric orbital lesions: bony and traumatic lesions

Orbital pathologies can be broadly classified as ocular lesions, extraocular soft-tissue pathologies (non-neoplastic and neoplastic), and bony and traumatic lesions. In this paper, we discuss the key imaging features and differential diagnoses of bony and traumatic lesions of the pediatric orbit and globe, emphasizing the role of CT and MRI as the primary imaging modalities. In addition, we highlight the adjunctive role of ocular sonography in the diagnosis of intraocular foreign bodies and discuss the primary role of sonography in the diagnosis of traumatic retinal detachment.

Orbital Perivascular Epithelioid Cell Tumor in a Case of Tuberous Sclerosis

The aim of the study was to report a case of orbital perivascular epithelioid cell tumor (PEComa) in a known diagnosed patient of tuberous sclerosis and retinal astrocytic hamartoma. 43-year-old female presented with rapid progressive painful proptosis in the left eye, also reported new mass growing in her upper back. The patient past medical history is significant for left renal angiomyolipoma and multiple bilateral lung cysts of which she underwent right nephrectomy and lung biopsy, respectively. The lung biopsy turned diagnostic for lymphangiomyomatosis. On external examination, the left eye was grossly proptotic with hypoglobus. A typical butterfly distribution of sebaceous adenoma was noted across the patient cheeks and nose. Visual acuity in the right eye was 20/20 and the left eye, 20/25. Funduscopic examination identified type 1, 2, and 3 retinal astrocytic hamartomas. MRI brain and orbit was significant for a lesion arising from the lateral orbital wall with extensive bone destruction, displacing the left optic nerve medially. CT chest showed left extrathoracic mass had same radiological features as the orbital lesion; thus, an incisional biopsy performed on the former was diagnostic for PEComa with atypical features. This is the first observed case of PEComa in a known diagnosed patent with TS and retinal astrocytic hamartoma. The association of tuberous sclerosis complex and orbital PEComa is rarely and poorly reported in the literature compared to extraocular PEComa.

Conjunctival Perivascular Epithelioid Cell Neoplasm With RBM10-TFE3 Fusion Presenting as Recurrent Subconjunctival Hemorrhage

Subconjunctival hemorrhages commonly present to eye care professionals and are frequently regarded as benign self-limited conditions. In selected cases, subconjunctival hemorrhages can be a harbinger of more severe disease. Perivascular epithelioid cell tumors, or PEComas, are rare mesenchymal neoplasms believed to originate from perivascular myoid cells and are rarely present in ocular structures. We present a rare case of a conjunctival perivascular epithelioid cell tumor that initially presented with recurrent subconjunctival hemorrhage. To our knowledge, this is the first description of a PEComa with a RBM10-TFE3 gene fusion, only previously seen with renal cell carcinoma. Physicians should be aware of this rare condition, its location in the fornix and its presentation as a recurrent subconjunctival hemorrhage.

Orbital TFE3-Rearranged Perivascular Epithelioid Cell Tumor: A Case Report and Review of the Literature

ABSTRACT

Perivascular epithelioid cell tumors (PEComas) are infrequent mesenchymal neoplasms that have particular histological and immunohistochemical features. Only a few cases have been described in the eye and orbit. This report presents a 28-year-old man who consulted for a painless left orbital mass. With the presumptive diagnosis of cavernous hemangioma, a surgical excisional biopsy was performed. Histopathological examination showed a well-delimited tumor composed of epithelioid cells with an eosinophilic cytoplasm and oval nucleus. The tumor cells stained diffusely for HMB-45 and transcription factor E3 (TFE3) and were focally positive for actin. There was no reactivity to S100 or desmin. Genetic testing revealed a TFE3 rearrangement. Based on these results, an extremely rare orbital TFE3-rearranged PEComa was diagnosed. Although no recurrence was seen at last follow-up, a review of the literature shows experience is limited regarding orbital PEComas and their malignant potential. Further research is needed to establish management guidelines, their association with the tuberous sclerosis complex, and the role of genetic mutations such as TFE3 rearrangement.

Primary malignant PEComa of the mandible. Report of an unusual case

Malignant PEComa is a rare entity that usually origins at visceral, retroperitoneal and abdominopelvic sites. In the present paper, we describe an extremely unusual manifestation of malignant PEComa involving the mandible in a 48 years-old female patient focusing on the anatomopathological findings and differential diagnosis. The therapeutic management based on the head and neck tumor board indications is also discussed.

Key words:Malignant PEComa, PEComa of the mandible, PEComa pathology, Oral cavity unusual neoplasm.

Thrombosed orbital arteriovenous malformation in a patient with lymphangioleiomyomatosis

A 47 year-old female with lymphangioleiomyomatosis developed right periorbital pain worsened while chewing, six months prior. Neuroimaging demonstrated a heterogenous inferotemporal right orbital mass extending through the inferior orbital fissure into the temporalis fossa, with flow voids. Given the patient's past medical history, the lesion was presumed to be a perivascular epithelioid cell tumor, a manifestation of lymphangioleiomyomatosis. A lateral orbitotomy revealed a well-circumscribed bluish-red lesion with areas of hemorrhage that was resected in total. Histopathology, however, was consistent with a thrombosed orbital arteriovenous malformation likely arising from the zygomaticotemporal neurovascular bundle. Lymphangioleiomyomatosis is a rare progressive disease that causes cystic destruction of the lungs and is frequently associated with extrapulmonary tumor infiltration, typically of the kidney and liver. Lymphangiomyoleiomyomatosis cell pathogenesis includes a pro-angiogenic micro-environment, classically expressing vascular endothelial factor-C and -D, which we postulate may have contributed to the development of the orbital arteriovenous malformation.

Ocular PEComas are frequently melanotic and TFE3-translocated: report of two cases including the first description of PRCC-TFE3 fusion in PEComa

Ocular perivascular epithelioid cell tumor (PEComa) is exceedingly rare. We reported two examples involving the choroid and subconjunctival tissue, respectively, in patients aged 17 and 20 years. Both tumors comprised packets and sheets of large polygonal cells with moderately pleomorphic nuclei and prominent nucleoli, traversed by delicate fibrovascular septa. Melanin pigmentation was present in one case. The tumors showed HMB45 and TFE3 immunoreactivity. TFE3 gene translocation was confirmed by FISH break-apart probes. RNA seq revealed PRCC-TFE3 and NONO-TFE3 fusions, with the former representing the first description of PRCC-TFE3 in PEComa. Critical reappraisal of the reported cases showed that ocular PEComa frequently affected young patents with melanin pigmentation, frequent TFE3 protein expression, and/or TFE3 gene translocation. No recurrence or metastasis was reported after complete excision despite the presence of cytologic atypia.

Perivascular epithelioid cell tumor (PEComa) of the pterygopalatine fossa

Perivascular epithelioid cell tumors (PEComas) are a rare group of mesenchymal tumors associated with tuberous sclerosis. These tumors are typically treated with resection and rarely recur or exhibit malignant behavior. A 78-year-old woman presented with an incidentally discovered pterygopalatine fossa/retroantral mass. Excisional biopsy was performed and revealed pathology consistent with PEComa. Upon review of the literature, there have been 43 reported cases of PEComa of the head and neck. There is only one previously reported case of PEComa in the skull base, and none reported in the pterygopalatine fossa. Of note, the previously reported case of skull base PEComa involved an aggressive tumor with widespread metastasis. Here, we report the first case of a PEComa of the pterygopalatine fossa/retroantral region, which was treated conservatively. This rare pathology should be considered in the differential diagnosis for atypical skull base tumors.