Malignant perivascular epithelioid cell tumor of the orbit: Report of a case and review of 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 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.

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.

Malignant perivascular epithelioid cell tumor mimicking jugular foramen schwannoma: A case report and literature review

Background

Perivascular epithelioid cell tumors (PEComas) of the skull base are extremely rare. Here we report the first description of a malignant PEComa mimicking jugular foramen schwannoma and presenting as Collet-Sicard syndrome, and we review the previous literature on PEComas of the head, neck and skull base.

Case description

A 29-year-old woman presented with hoarseness, dysphagia, vomiting, and headache. She was first diagnosed with Collet-Sicard syndrome caused by thrombosis of the sigmoid and transverse sinuses. She was treated with anticoagulant therapy, and the hoarseness and paralysis of the accessory nerve improved. Later, at age 31, the hoarseness again worsened. At another hospital, enhanced computed tomography revealed a tumor in the jugular foramen extending to the neck and medially displacing the internal carotid artery. She was referred to our hospital for further examination and was diagnosed with jugular foramen schwannoma causing thrombosis of the sinuses. At the one-year follow-up, the tumor had grown rapidly and had started to surround the internal carotid artery. We therefore performed a tissue biopsy of the tumor in the jugular foramen and neck. Based on pathological analysis, we made a definitive diagnosis of malignant PEComa.

Conclusions

It may be extremely challenging to reach an accurate diagnosis of PEComa in the skull-base region, which can cause a delay in treatment initiation. When atypical clinical features for a skull-base tumor are found, we recommend preliminary biopsy to obtain a definitive diagnosis and initiate an appropriate treatment strategy as early as possible.

Multifocal perivascular epithelioid cell tumor of the uterus: report of one case and literature review

BACKGROUND

The tumor with perivascular epithelioid cells (PEComa) is a rare mesenchymal tumor originating from a perivascular epithelioid cell line. The uterus is the most common location of PEComa, but multifocal lesions are rare. This study aimed to analyze the clinicopathologic and histochemical characteristics of uterine PEComa.

METHODS

1 case of uterine PEComa was detected by H&E staining and immunohistochemical SP method.

RESULTS

The 41-year-old female patient was admitted to the hospital due to gynecologic ultrasonography which showed a substantial heterogeneous mass in the pelvic cavity. According to the microscopic features and immunohistochemical markers, the tumor was diagnosed as multifocal tumors with perivascular epithelioid cells, specifically located on the serous surface of the uterus and below the right appendix. The immunophenotype of the patient was positive for Vimentin, HMB45, TFE-3 and WT-1, but negative for SMA, S-100, CD10, CK, EMA, CD117, CD31 and Melan-A.

CONCLUSION

PEComa is a rare mesenchymal tumor with benign manifestations. Pathological diagnosis should be combined with morphology and immunophenotype. The characteristic immunomarkers are HMB45, Melan-A and SMA. The understanding of clinical manifestations and pathologic features can improve the diagnosis and prevention of this type of tumor in female patients.

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

Aim

To describe and review the clinical, radiological, and histopathological characteristics of an orbital perivascular epithelioid cell tumor (PEComa).

Methods

A systematic review of clinical records, radiological investigations, microscopic features, and immunohistochemical characteristics was done.

Results

A 9-year-old female child presented with a year-long history of a large orbital mass associated with painless, progressive proptosis of the right eye. Radiologically, a well-defined orbital mass was seen with no intracranial extension. Excision was performed and histopathological examination showed uniform epithelioid cells in nests separated by thin fibrovascular septae. The tumor cells stained positively for Human Melanoma Black-45, but neg-atively for desmin, S-100, smooth muscle actin, MyoD1, microphthalmia-associated transcription factor, vimentin, CD10, CD31, and CD34 with a low proliferation index of 5-7%. Based on the tumor's morphological and immuno-histochemical characteristics, a diagnosis of giant orbital PEComa was made. No recurrence was seen at the last follow-up.

Conclusions

PEComas are uncommon mesenchymal neoplasms that have typical histological features, with an immunohistochemical profile of negativity for epithelial markers and positivity for melanocytic markers. For benign PEComas, complete excision is advised. However, since PEComas elsewhere in the body have been known to be malignant, a close follow-up of such cases is recommended.