Cytologic features and immunohistochemical findings of epithelioid hemangioendothelioma (EHE) in effusion: A case series

Pleural epithelioid hemangioendothelioma in a 39-Year-old female: a case report

BACKGROUND

Epithelioid hemangioendothelioma (EHE) is a rare malignancy of vascular origin which can be primarily be seen in various tissues. EHE originating from the pleura is an even more uncommon subtype which may mimic mesothelioma and pleural carcinomatosis. The prognosis of pleural EHE is poor and there is no consensus on the optimal therapeutic approach.

CASE PRESENTATION

A 39-year-old middle-eastern female presented with progressive dyspnea and left shoulder discomfort. Chest computed tomography scan revealed a left side pleural effusion and pleural thickening. Pleuroscopy was done and biopsies were taken which were positive for CD31, CD34, CK, factor 8-R-antigen, and vimentin. Patient was diagnosed with pleural epithelioid hemangioendothelioma (PEHE) and chemotherapy was started and underwent extrapleural pneumonectomy 7 months later. Unfortunately, the patient passed away 10 months after diagnosis due to disease complications.

CONCLUSIONS

Once PEHE is suspected in histology it can be confirmed with immunohistochemistry. Chemotherapy, surgery or a combination of both is currently used as the treatment but the standard treatment remains a question.

Cytopathologic features of epithelioid hemangioendothelioma including touch imprints for rapid on-site evaluation

Objectives

Epithelioid hemangioendothelioma (EHE) is a vascular tumor of intermediate malignant potential, which presents as infiltrative lesions involving multiple organs. We reviewed our institutional experience with the cytologic diagnosis of this neoplasm including the performance of rapid on-site evaluation (ROSE).

Material and Methods

From our institutional database, we identified 29 cytology specimens, obtained between 2012 and 2020, from 21 patients with biopsy confirmation of EHE. ROSE and final diagnosis were compared. All cytology slides were reviewed, and selected cytologic features were recorded.

Results

The cohort included 29 specimens comprising 17 (59%) from liver, 6 (21%) from lung, 2 (7%) from lymph node, and 4 (14%) from other sites. At ROSE, 8/27 (30%) were reported inadequate, yet on review, all cases contained scattered cells typical of EHE in the touch imprint air-dried slides including two cases reported with a final diagnosis of non-diagnostic. All cases contained epithelioid and plasmacytoid cells with ovoid nuclei, fine chromatin, delicate (or biphasic) cytoplasm, and scattered cells with delicate, elongated cytoplasmic tails. The majority 26/29 (90%) of cases had multi-nucleated and multi-lobated nuclei. Intracytoplasmic lumens/blister cells were in 17/29 (59%), and a subset had erythrocytes therein (4/29, 14%). Metachromatic fibromyxoid or fibrotic stroma fragments were commonly seen (23/29, 79%). Mitoses and necrosis were absent in all cases. Of 11 tested cases, WWTR1::CAMTA1 and YAP1::TFE3 fusions were detected in nine and two cases, respectively.

Conclusion

EHE has distinctive cytologic features which are often under-recognized during ROSE.

Characteristic contrast‑enhanced ultrasound findings of hepatic epithelioid haemangioendothelioma: A case report and literature review

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare liver tumor, which is usually diagnosed by pathological examination, since the diagnostic imaging criteria remain to be defined. However, contrast-enhanced ultrasound (CEUS) may reveal the characteristic features of HEHE to aid diagnosis. In the present study, two-dimensional ultrasound examination of a 38-year-old male patient showed a mass in the right liver. CEUS showed an S5 segment hypoechoic nodule, and imaging features resulted in the diagnosis of HEHE. Surgery was shown to be an appropriate and successful treatment for HEHE. In conclusion, CEUS may be valuable for the diagnosis of HEHE, thereby avoiding the serious consequences of misdiagnosis.

Serous fluid: Metastatic sarcomas, melanoma, and other non-epithelial neoplasms

While most tumors metastatic to the serous membranes are of epithelial origin, cytologists should be aware that non-epithelial neoplasms can also cause malignant effusions including sarcomas, melanomas, germ cell tumors, and, more rarely, brain tumors. The differential diagnosis of a malignant effusion is accordingly broad, especially for the small round blue cell tumors that includes not only mesenchymal tumors, but also non-mesenchymal tumors, such as neuroblastoma and Wilms tumor. Diagnosing non-epithelial malignancies in effusion specimens based entirely upon their cytomorphologic features is difficult because these neoplasms often exhibit considerable morphological overlap and their cytomorphology can differ from the original tumor. As malignant cells have a tendency to round up in body fluids these non-epithelial neoplasms can therefore mimic reactive mesothelial cells and metastatic adenocarcinoma. The use of ancillary studies including immunostaining, FISH, and molecular studies is thus often critical to reach a definitive diagnosis. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Diagnostic Cytopathology of Serous Fluids.

Bone and soft tissue sarcomas in cerebrospinal fluid and effusion: A 20-year review at our institution

BACKGROUND

The literature on bone and soft tissue sarcomas (BSTSs) involving effusions and cerebrospinal fluid (CSF) is very limited.

METHODS

A computerized search for fluid cytology with a sarcoma diagnosis from 2000 to 2020 was performed. All available cases, including the clinical follow-up, were reviewed.

RESULTS

A total of 57 fluids specimens from 36 BSTSs were identified (9 rhabdomyosarcomas, 6 angiosarcomas, 5 epithelioid hemangioendotheliomas, 3 dedifferentiated liposarcomas, 2 chondrosarcomas, 1 extraskeletal myxoid chondrosarcoma, 3 Ewing sarcomas, 2 undifferentiated sarcomas, 3 osteosarcomas, 1 synovial sarcoma, and 1 hybrid low-grade fibromyxoid sarcoma/sclerosing epithelioid fibrosarcoma). There were 22 males and 14 females. The age range was 4 to 82 years (median, 45 years). Sites of involvement included pleural fluid (n = 38), peritoneal fluid (n = 14), and CSF (n = 5). Twenty-four cytology cases were available for review. The cytologic features were nonspecific and ranged from dyshesive to clusters of round, epithelioid, pleomorphic, and occasionally spindle-shaped malignant cells that could easily mimic other non-BSTS malignant tumors. The diagnosis of BSTS was made by comparison with a prior specimen and/or ancillary studies (molecular or immunohistochemical stains). The prognosis was poor because 95% of the patients died of their disease.

CONCLUSIONS

The incidence of BSTS in fluid cytology is extremely rare, and it can have cytologic features similar to those of non-BSTS malignancies. Although, in most cases, a comparison with a prior known BSTS specimen may suffice, the use of ancillary studies is extremely helpful in arriving at the correct diagnosis. However, in cases with no known prior malignancy, including BSTS in the differential diagnosis is prudent for preventing misdiagnosis.

WWTR1(TAZ)-CAMTA1 gene fusion is sufficient to dysregulate YAP/TAZ signaling and drive epithelioid hemangioendothelioma tumorigenesis

Epithelioid hemangioendothelioma (EHE) is a genetically homogenous vascular sarcoma that is a paradigm for TAZ dysregulation in cancer. EHE harbors a WWTR1(TAZ)-CAMTA1 gene fusion in >90% of cases, 45% of which have no other genetic alterations. In this study, we used a first of its kind approach to target the Wwtr1-Camta1 gene fusion to the Wwtr1 locus, to develop a conditional EHE mouse model whereby Wwtr1-Camta1 is controlled by the endogenous transcriptional regulators upon Cre activation. These mice develop EHE tumors that are indistinguishable from human EHE clinically, histologically, immunohistochemically, and genetically. Overall, these results demonstrate unequivocally that TAZ-CAMTA1 is sufficient to drive EHE formation with exquisite specificity, as no other tumor types were observed. Furthermore, we fully credential this unique EHE mouse model as a valid preclinical model for understanding the role of TAZ dysregulation in cancer formation and for testing therapies directed at TAZ-CAMTA1, TAZ, and YAP/TAZ signaling.