A woman presented with right shoulder pain and immobility. Imaging demonstrated a lesion crossing the joint, which is common with infection. However, biopsy revealed epithelioid haemangioendothelioma (EHE), which is a rare vascular tumour that occasionally occurs in bone. This is the first reported case of EHE in the shoulder.
A 54-year-old woman presented with pain and reduced mobility in her right shoulder, which had been reconstructed previously. Plain film showed a lucent central area in the right glenoid surrounded by irregular sclerosis projecting inferiorly (Figure 1). CT showed a mixed sclerotic and lytic lesion in the right glenoid with a scalloped erosion anteriorly, and calcification in soft tissues (Figure 2). MRI revealed oedema in the humeral head and surrounding soft tissue with abnormal post-contrast enhancement (Figure 3). These appearances were thought to be infective due to involvement of both the humeral head and the glenoid, despite the absence of raised infective markers and fever. A CT guided biopsy provided a histological diagnosis of EHE, which was supported by positive cytoplasmic staining for CD31 and vimentin, and negative staining for cytokeratin. The tumour was excised, and the peri-operative biopsy showed some solid areas of tissue with more nuclear atypia than usually seen in EHE, therefore it was classified as a malignant haemangioendothelioma. Eight months later the tumour recurred and the patient had an en bloc excision of the proximal humerus, distal clavicle and distal scapula, with insertion of a right shoulder prosthesis (Figure 4). A follow up PET scan one month later showed no evidence of recurrence (Figure 5) and the peri-operative histology report confirmed clear margins of resection. The recurrent tumour cells stained positive for CD34 and CD31, and negative for cytokeratin (Figure 6). Fifteen months after initial presentation the patient is alive and well.
The management of EHE is not straightforward due to poor correlation between clinical behaviour and histological grade (1, 2, 3). A grading system has been suggested (4) but this has been refuted in other studies (5). Establishing a specific grade can also be difficult as some tumours have variable areas of differentiation (4, 6), as was almost certainly present in the current case. Multifocal tumours are thought to have a better prognosis (4, 7), but this has also been questioned (2, 5). In addition, as EHE is rare, it has been difficult to perform a study with sufficient statistical power to provide definitive answers. It can also be difficult to differentiate EHE from conventional epithelioid haemangiomas of bone (8), and in one series, 5% of EHE were diagnosed histologically as haemangiomas (2), although the use of vascular markers such as CD31 and CD34 can aid histological diagnosis (3). Therefore, it has been proposed that EHE should be treated as a malignant neoplasm, despite a lower metastasis rate and lower mortality than conventional angiosarcomas, including epithelioid angiosarcomas (3). Lesions are typically lytic on plain film, and periosteal reactions are rare (9, 10). They are usually well defined measuring 1-2 cm in diameter, and become more aggressive and less well defined at larger diameters of 5 cm (11). Areas of cortical destruction and expansion can occur separately or in combination (2), although coritcal changes and soft tissue extension are uncommon (9). Multiple lesions clustered in the same region strongly support the diagnosis of EHE or conventional haemangioendothelioma (2). CT and MRI identify the extent and pattern of bone destruction and soft tissue extension (9), although CT offers no distinct advantage when imaging soft-tissue haemangioma, compared with plain film and MRI in combination (12). The typical MRI appearance of EHE, as with similar vascular tumours (13), is low signal intensity on T1 weighted images and intermediate to high signal with T2 (10, 14, 15). However, well-differentiated lesions may show increased signal with T1, and more aggressive lesions may show decreased signal with T1 (13). Bone scans can also be used for staging (9) although the degree of skeletal involvement may be underestimated. Therefore, the best current imaging strategy is a skeletal survey, as many lesions are asymptomatic, followed by MRI, which has also identified previously unsuspected lesions (16). Treatment options are not straightforward due to age variability, lesion location, multifocality and variable clinical behaviour (17). Currently, the main option is radical resection, although radiation therapy has been helpful in some multifocal tumours (2, 9). Amputation with or without radiotherapy has also been advocated for multifocal tumours (7). However, there has been some success with radiofrequency ablation (17), particularly with multifocal lesions, which are usually of moderate size. In summary, histology and immunohistochemistry, in combination with a skeletal survey and MRI, is the best strategy for establishing a diagnosis. The advent of radiofrequency ablation may allow a reduction in the need for radical surgery.
Malignant epithelioid haemangioendothelioma of the right shoulder
1. X-ray Plain Film: A moth-eaten or lytic lesion is observed in the right shoulder joint (primarily the proximal humerus). The boundary is relatively clear, with minimal periosteal reaction. There is evidence of destruction near the joint surface, but no significant soft tissue swelling is noted.
2. CT Scan: Further confirmation of local bone destruction in the proximal humerus, presenting as a lytic lesion. Slight cortical thinning or destruction is observed locally, yet no extensive soft tissue invasion is evident. Unlike a simple bone cyst or common metastatic tumor, an irregular tissue density may be seen within the lesion.
3. MRI Examination: On T1-weighted images, the lesion exhibits relatively low signal intensity, and on T2-weighted images, it shows medium-to-high signal intensity, suggesting features of a vascular or soft tissue tumor. Partial involvement is seen near the joint surface, but there is no significant formation of a large soft tissue mass. MRI aids in determining the extent of the lesion within the bone and around the joint.
4. Histopathology: Biopsy shows epithelioid cells suggestive of vascular endothelial origin (Epithelioid cells). Immunohistochemistry reveals positive staining for vascular markers such as CD31 and CD34, consistent with a vascular-derived tumor.
Considering the patient’s age, clinical symptoms, imaging findings, as well as biopsy pathology and immunohistochemistry results, the most likely diagnosis is: Epithelioid Hemangioendothelioma (EHE). Due to its rarity and unique morphological features, pathological examination and immunohistochemical confirmation are required. If uncertainty remains in imaging or clinical diagnosis, further multidisciplinary discussion or additional imaging of other areas is recommended to rule out multifocal lesions.
Given that the patient is a middle-aged female with shoulder joint lesions involving bone tissue and limited joint mobility, rehabilitation during or after treatment should emphasize the following principles:
Overall, close attention should be paid to bone integrity and pain levels throughout rehabilitation to prevent secondary injuries. Exercise intensity and duration should be increased gradually, following the FITT-VP principle (Frequency, Intensity, Time, Type, Volume, Progression) and adjusted based on the patient’s tolerance.
Disclaimer: This report is a reference analysis based solely on existing imaging and clinical data. It does not replace in-person consultation or a professional doctor’s diagnosis and treatment plan. Specific treatment should be determined by the patient in collaboration with a professional medical team, based on the patient’s individual condition.
Malignant epithelioid haemangioendothelioma of the right shoulder
