Background

Cavernous hemangioma (CH) is a common benign tumor with vascular origin. It can grow in many locations and its occurrence in some organs, like the liver, is so frequent that it is considered the most common primary tumor of the liver [1]. Nevertheless, an incidence rate of less than 0.5% makes cavernous hemangioma of mediastinum (CHM) a rare cause of mediastinal mass [2].

While there have been reports of CH in the middle mediastinum, the majority of hemangiomas tend to present in the anterior mediastinum [3, 4]. A preoperative definite diagnosis is somewhat challenging due to the rarity of CHM and its nonspecific clinical manifestation, and paraclinical findings and diagnosis are often made after total resection of the tumor, which is the mainstay of management [5, 6]. Here, we intend to present a case of CHM with no symptoms other than persistent cough.

Case presentation

A 48-year-old man was referred to our center after dealing with a persistent severe cough for more than a month. Past medical history was positive for hypertension. He also had a recent episode of syncope which had been resolved spontaneously. Vital signs were within the normal range with an arterial oxygen saturation of 97%. Physical examinations were unremarkable including heart and lung examination. Laboratory findings were also unremarkable.

In order to evaluate his persistent cough, spiral chest computed tomography (CT) scan with intravenous contrast was performed which revealed a heterogeneous lobulated mass in the anterior superior mediastinum measuring 125 × 77 × 99 mm in size, with pressure over the aortic arch, and mild pericardial effusion (Fig. 1).

Fig. 1
figure 1

Chest computed tomography scan showing a large mediastinal mass; A Sagittal view, B coronal view, and C axial view

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A tru-cut biopsy from the mass was reported as a benign vascular tumor. The patient was operated to resect the mass. During the operation a full sternotomy was conducted. The pleura was opened and a bilateral mediastinal pleurectomy was performed. The tumor was then dissected from the diaphragm, as well as pericardium. Due to encasement of innominate vein by the mass, a dissection of the tumor and innominate vein was performed, while preserving both phrenic nerves.

The specimen was sent for pathologic examination. The gross examination of the tissues obtained from surgery showed a bosselated brown soft tissue (12 × 11 × 6 cm) and a fragment of fibro-fatty tissue (7.5 × 4 × 3 cm) (Fig. 2). Cut section of the tumor was hyper-vascular filled with blood, exhibiting brown color. Microscopic histopathological evaluation of the tumor showed large and dilated vascular channels filled with blood. The vascular spaces were lined by normal and bland looking endothelial cells. These histopathologic features were typical for CH. A reactive lymph node was also identified (Fig. 3).

Fig. 2
figure 2

Gross lobulated mass in the anterior mediastinum identified as cavernous hemangioma

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Fig. 3
figure 3

H&E staining of anterior mediastinum mass demonstrating large and dilated vascular channels filled with blood, with vascular spaces lined by normal and bland looking endothelial cells, typical for cavernous hemangioma

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The patient had an uncomplicated surgery and a postoperative chest X-ray was unremarkable (Fig. 4). The patient was discharged in good condition a week after the operation. The patient is relatively well and completely symptom free during his fourth month follow-up.

Fig. 4
figure 4

Post-operative chest X-ray of 48-year-old male patient undergoing Cavernous Hemangioma of mediastinum tumoral resection

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Discussion

Cavernous Hemangioma of mediastinum (CHM) is a rare benign tumor originating from vascular endothelial cells. It is mainly an internally endothelium lined multilocular mass consisted from cavernous sinusoids of varying size [2, 7]. A rare cause of mediastinal mass is CHM, which usually involves the anterior mediastinum [2, 5]. However, there have been reports of posterior [8, 9], middle [3, 4] and even concurrent anterior and middle [10] mediastinum involvements. We further investigated all reports regarding CHM among the major databases of PubMed, Scopus, Web of Science, and Google Scholar, based on related Mesh terms (“Cavernous Hemangioma”, and “Mediastinal” or similar phrases) till before October 2022. The related reports are described in Table 1.

Table 1 Literature review of mediastinal tumor cases
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Based on the mentioned cases in Table 1 and our literature review, a total of 77 patients with mediastinal mass have been reported to date, with the oldest being reported on 1953 [63]. Among them, 31 (40.3%) were male and 46 (59.7%) were female. The age of the patients varied from a new born to 74 years with an average of 39.18 ± 21.67. Among the patients, 19 (24.7%) had no significant past medical history. The symptoms of the patients included cardiac symptoms in 19 (25.3%) and pulmonary symptoms in 26 (34.7%) of the patients, while also incidental in 26 (33.8%) of the cases. The most common location of the tumour was in the anterior mediastinum in 41 (53.2%) of cases, followed by middle mediastinum in 16 (20.8%) of cases, superior mediastinum in 16 (20.8%) of the cases, and posterior mediastinum in 12 (15.6%) of the cases. The size of the tumor ranged from 17 to 215 (median 56, Q1–Q3: 30–90.50), while the weight ranged from 20 to 1075 (median: 170, median 170, Q1–Q3: 52.0–657.5) grams. Treatment included surgical resection in 71 (92.2%) of the patients, in which two also received medication prior to surgery. Also, two (2.6%) patients solemnly received conservative management. The median follow-up duration was 12 [Q1–Q3: 6–33.75] months and the mortality rate was 40 (51.9%). Furthermore, two (2.6%) of the cases were diagnosed during autopsy.

A paper by Cohen et al. published in 1987 was the first comprehensive case series regarding CHMs. They presented 15 cases of CHM with 8 of them being asymptomatic [2]. This is consistent with a recent retrospective systematic review conducted by Li et al., when 52 percent of their studied cases were asymptomatic, discovered during routine checkups and imaging studies performed for other reasons [6]. Aside from the asymptomatic cases, clinical presentation usually correlates with the location of the tumor in the mediastinum and the compression it puts on the adjacent structures [2]. Symptoms include cough, dyspnea, chest pain, hemoptysis, plural effusion, and in some extreme situations, CHMs can present as congestive heart failure [39, 64]. The persistent cough noted in our patient is unique due to the fact it was the sole presenting symptom. A similar case in a study by Bagheri et al. presented not only with cough, but also with a large neck mass [16].

CHM’s imaging finding usually indicates a round to oval-shaped mass with a well-defined border, but it can also invade adjacent organs and this renders the tumor border to be hazy to an extent that it can be confused with a malignant lesion [7, 65]. The presence of phleboliths, pampiniform growth pattern and aberrant draining veins are relatively specific in diagnosing CHMs [6]. Magnetic resonance imaging can be helpful in CT suspected cases of CHM [7]. Markedly high intensity on fat suppression T2-weighted image might be a characteristic feature of CHMs [66]. Fatty components in the peripheral region of tumor is a sensitive indicator for CHM, but a central fatty component is not sensitive as it can also be seen in teratomas [6]. Table 2 demonstrates most common causes of anterior mediastinal masses in a comparative style.

Table 2 Differential diagnosis of anterior mediastinal masses
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Just like our case, a CHM diagnosis is usually established after surgery and examination of the excised tumor, and preoperative diagnosis is seldomly reached [9]. This was also evidenced by a case series of 18 patients by Xu et al. in which two cases had an accurate preoperative diagnosis. They concluded their study by describing their surgical approach to these patients. While eight of their cases were initially treated by video-assisted thoracic surgery, three of them required thoracotomy due to extensive hemorrhage. This made their total number of thoracotomies 13 out of 18 cases [69]. Hence, we used the more traditional approach of thoracotomy in our patient.

While it has been proposed that a subtotal resection would suffice without any increase in morbidity and mortality [2], we performed a total resection due to encasement of the innominate vein by tumor and adhesions to pleura.

There have been reports of additional treatments alongside surgery. Radiotherapy and extracorporeal membrane oxygenation has been used in cases of CHMs with low platelet counts (i.e. Kasabach–Merritt syndrome) and massive hemoptysis, respectively [70, 71].

Conclusion

Cavernous Hemangioma, a rare cause of mediastinal mass, should be considered in the differential diagnosis of mediastinal tumors. Our review of literature demonstrated a female dominance and average age of 40 years, with a 52% mortality rate based on previous reports. While imaging study can be helpful in diagnosing these benign lesions, it often needs surgery for both definite diagnosis and treatment.