Laparoscopic microwave ablation for giant cavernous hemangioma coexistent with diffuse hepatic hemangiomatosis: Two case reports

Abstract

BACKGROUND

Hepatic hemangioma represents the most common benign primary hepatic neoplasm. Although most such tumors are small and asymptomatic, giant cavernous hemangioma (GCH) is frequently symptomatic, and needs intervention. Moreover, diffuse hepatic hemangiomatosis (DHH) is not rare in the liver parenchyma adjacent to a GCH. The management strategy for hepatic hemangiomas can differ depending on the presence of associated hemangiomatosis and the amount and distribution of the residual hepatic parenchyma.

CASE SUMMARY

Herein, we report two patients with GCH coexistent with DHH successfully treated by laparoscopic microwave ablation. The two GCHs were ablated completely and the ablated zone atrophied obviously in imaging follow-ups after ablation. Surprisingly, there was a trend toward gradual reduction and diminishment of DHH.

CONCLUSION

Thermal ablation treatment might be an effective and less invasive treatment for GCH coexistent with DHH around the hemangioma.

Key Words: Giant cavernous hemangioma; Diffuse hepatic hemangiomatosis; Management; Microwave; Thermal ablation; Case report

Core Tip: Hepatic hemangiomas are the most common benign liver tumors, with giant cavernous hemangioma (GCH) often requiring intervention. This report discusses two patients with GCH coexistent with diffuse hepatic hemangiomatosis (DHH), treated successfully with laparoscopic microwave ablation. Both GCHs were completely ablated, showing significant atrophy on follow-up imaging. Notably, there was also a gradual reduction in DHH. These findings suggest that thermal ablation may be an effective and minimally invasive option for managing GCH coexistent with DHH.

INTRODUCTION

Hepatic hemangioma is the most frequently encountered solid benign liver neoplasm, with an incidence of 3% to 20% in the general population[1]. Giant cavernous hemangioma (GCH) is defined as being ≥ 5 cm and warranting therapy when it leads to continuous growth in clinical symptoms or the risk of complications[2]. Diffuse hepatic hemangiomatosis (DHH) is an uncommon disease of undetermined etiology characterized by numerous hemangiomas infiltrating and replacing the liver parenchyma[3,4]. In contrast to GCH, which presents with smooth, well-defined margins and typical imaging characteristics, DHH appears as a poorly defined lesion[5]. Isolated DHH without extrahepatic involvement is exceedingly rare in adults.

However, hemangiomatosis is frequently occurs in the liver parenchyma adjacent to a GCH[5]. The approach to managing hepatic hemangiomas varies based on the presence of associated hemangiomatosis and the extent and location of the remaining hepatic parenchyma. Surgical candidates must be selected with caution to mitigate complications, including excessive intraoperative blood loss and the risk of postoperative liver failure resulting from overestimation of functional residual liver volume due to unrecognized involvement by hemangiomatosis. Recently, thermal ablation treatment using radiofrequency (RF) ablation or microwave (MW) ablation has been investigated as a less invasive treatment for hepatic hemangioma, which has shown favorable outcomes[6,7]. However, thermal ablation has not been described in the published papers of hepatic hemangioma coexistent with DHH. We herein present two cases with GCH coexistent with DHH around the hemangioma that were treated successfully by laparoscopic MW ablation.

CASE PRESENTATION

Chief complaints

Case 1: In September 2022, a 63-year-old female was admitted to the hospital due to abdominal discomfort.

Case 2: In January 2024, a 54-year-old female was admitted to the hospital because regular follow-up images showed an enlarging hepatic hemangioma over the past 5 years.

History of present illness

Case 1: A hepatic hemangioma and multiple hepatic nodules were incidentally identified during a routine health check via abdominal ultrasound (US).

Case 2: No other specific discomfort was described.

History of past illness

Case 1: The patient had a documented history of hypertension.

Case 2: The patient had no previous abnormalities.

Personal and family history

No significant personal or family history was reported by both patients.

Physical examination

The physical examination findings of case 1 and case 2 were within normal limits.

Laboratory examinations

Laboratory tests revealed no abnormalities for both patients.

Imaging examinations

Case 1: A contrast-enhanced computed tomography (CT) scan demonstrated peripheral enhancement of the GCH (7.4 cm × 9.9 cm) and heterogeneous enhancement of the adjacent liver parenchyma affected by hemangiomatous lesions (Figure 1A-D).

Figure 1 Initial contrast-enhanced computed tomography scan of the abdomen obtained, intraoperative findings and follow-up contrast-enhanced computed tomography scan of the abdomen obtained of case 1. A-D: Initial contrast-enhanced computed tomography (CT) scan of the abdomen obtained. A hemangioma (9.9 cm, white arrow) is evident in the left lateral segment of the liver, with multiple disseminated small enhanced nodular lesions (black arrows) adjacent to the hemangioma (A: Arterial phase; B: Arterial phase; C: Venous phase; D: Venous phase); E: Intraoperative findings of complete giant cavernous hemangioma (GCH); F: Microwave ablation of GCH, with the first application being launched from the exterior margin of the tumor; G: The second puncture point should be selected at the edge of the ablated zone rather than at the hemangioma to avoid bleeding at the puncture site. At the same time, numerous variably-sized red nodules were present near the GCH; H: After ablation, the ablated zone atrophied and collapsed; I-L: Follow-up contrast-enhanced CT scan of the abdomen obtained. Three months after ablation, contrast-enhanced CT revealed that the hemangioma was completely ablated, and the ablated zone (orange arrow) volume decreased. The reduction in the size of remained diffuse hepatic hemangiomatosis (blue arrow) was noted (I: Arterial phase; J: Arterial phase; K: Venous phase; L: Venous phase); M-P: Twenty months after ablation, contrast-enhanced CT showed that the ablated zone (orange arrow) had decreased further, with obvious shrinkage of the subtle residual diffuse hepatic hemangiomatosis (blue arrow) (M: Arterial phase; N: Arterial phase; O: Venous phase; P: Venous phase).

Case 2: Contrast-enhanced CT demonstrated a GCH (10.7 cm × 8.2 cm) and multiple small hemangiomatous lesions adjacent to the hemangioma in the liver (Figure 2A and B).

Figure 2 Initial contrast-enhanced computed tomography scan of the abdomen obtained, intraoperative findings, histological findings of resected liver tissue and follow-up contrast-enhanced computed tomography scan of the abdomen obtained of case 2. A and B: Initial contrast-enhanced computed tomography (CT) scan of the abdomen obtained. A hemangioma (10.7 cm, white arrow) is evident in the liver, with multiple disseminated small enhanced nodular lesions (black arrow) adjacent to giant cavernous hemangioma (GCH) (A: Arterial phase; B: Venous phase); C: Intraoperative findings of complete GCH; D: Multiple small hemorrhagic blood-filled honeycomb areas from 2-3 mm up to 3 cm in diameter were scattered adjacent to the GCH throughout the entire left lobe; E: The first application was launched from the exterior margin of the GCH; F: After ablation, the ablated zone atrophied and collapsed. Diffuse hepatic hemangiomatosis was left in situ without ablation; G and H: Histological findings of resected liver tissue revealed that the large majority of the portal tracts and the central veins showed expansion due to the formation of micro-angiomas along with dilatation of the native vessels. And micro-angiomatous lesions characterized by irregular-shaped dilated vascular channels arranged along with sinusoidal dilatation with some accompanied by tumor-like proliferation and red blood cell siltation seen in the lumen, and the stroma was hyperplastic fibrous tissue. The lesion was lined with flat endothelial cells without cellular atypia (black arrowhead). This lesion was diagnosed as hemangiomatosis (hematoxylin and eosin staining, G: 5 ×; H: 10 ×); I and J: Follow-up contrast-enhanced CT scan of the abdomen obtained. Three months after ablation, contrast-enhanced CT revealed that the hemangioma was completely ablated, and the ablated zone (orange arrow) volume decreased; The reduction in the size of remained diffuse hepatic hemangiomatosis (blue arrow) was noted (I: Arterial phase, J: Venous phase).

FINAL DIAGNOSIS

Based on imaging findings and clinical features, both patients in the study were diagnosed with GCH coexistent with DHH.

TREATMENT

Case 1

Following multidisciplinary team discussions, laparoscopic MW ablation was planned and executed to target the hemangioma. Two hepatobiliary surgeons, each with over a decade of experience in percutaneous and laparoscopic image-guided MW ablation of giant hemangiomas, performed the procedures (Figure 1E-H). Tumor coagulation was achieved using an ECO-100Al8 internally cooled MW antenna and a water-cooled MW ablation system (Yigao Medical, Nanjing, China), with the power output set at 150 W and a frequency of 2450 MHz. Details of the MW ablation process have been previously described[1]. Intraoperative US monitored tissue responses, with hyperechoic areas indicating adequately ablated tissue due to gas release from heating. DHH lesions were left intact to preserve as much normal liver parenchyma as possible. The ablation procedure lasted 56 minutes, with a total operative time of 125 minutes, including 20 sessions of ablations at different tumor sites. Intraoperative blood loss, quantified through drained blood, was measured at 10 mL.

Case 2

Two hepatobiliary surgeons, each with over a decade of experience in percutaneous and laparoscopic image-guided MW ablation of giant hemangiomas, performed the procedures as previously described (Figure 2C-F). In the operative field, multiple small hemorrhagic blood-filled honeycomb areas from 2-3 mm up to 3 cm in diameter were scattered adjacent to the GCH throughout the entire left lobe (Figure 2D). To further obtain a definitive diagnosis, a liver biopsy was conducted from the left hepatic lobe. The ablation procedure lasted 37 minutes, with a total operative time of 165 minutes, including 5 sessions of ablations at different tumor sites. Intraoperative blood loss was measured at 20 mL. Histological findings of the resected liver tissue revealed that the large majority of the portal tracts and the central veins showed expansion due to the formation of micro-angiomas along with dilatation of the native vessels. Micro-angiomatous lesions were characterized by irregular-shaped dilated vascular channels arranged along with sinusoidal dilatation, some accompanied by tumor-like proliferation and red blood cell siltation seen in the lumen, and the stroma was hyperplastic fibrous tissue. The lesion was lined with flat endothelial cells without cellular atypia. This lesion was diagnosed as hemangiomatosis (Figure 2G and H).

OUTCOME AND FOLLOW-UP

Case 1

The patient was discharged on postoperative day 3 without significant complications, such as intrahepatic hematoma, and was in good health at the latest follow-up. Three months and 18 months after ablation, contrast-enhanced CT scans showed that the GCH was completely ablated and remarkably smaller. Moreover, a reduction in the size of DHH was noted (Figure 1I-P). No recurrence or delayed complications were identified, and the patient’s subjective health status and quality of life were assessed as good to excellent at the final follow-up.

Case 2

The patient was discharged on postoperative day 5 without significant complications, such as intrahepatic hematoma, and was in good health at the latest follow-up. Four months after ablation, contrast-enhanced CT scans showed that the hepatic hemangioma was completely ablated and remarkably smaller. Moreover, a reduction in the size of DHH was noted too (Figure 2I and J). Subsequently, we will continue to monitor the patient’s follow-up one year after ablation. No recurrence or delayed complications were identified, and the patient’s subjective health status and quality of life were assessed as good to excellent at the final follow-up.

DISCUSSION

Hepatic hemangiomas are the most common benign liver tumors incidentally detected in most patients. DHH is a rare disease characterized by ill-defined tissue with a similar histological presentation to typical cavernous hemangiomas, replacing the hepatic parenchyma[5,8,9]. Histological features of DHH include irregularly dilated non-anastomotic vascular spaces lined with flat endothelial cells, infiltration of the native hepatic parenchyma without any encapsulation, and the latter two features distinguishing it from a cavernous hemangioma. However, hemangiomatosis is not rare in the liver parenchyma adjacent to a GCH[5]. Jhaveri et al[5] evaluated 41 patients who had undergone CT or magnetic resonance imaging (MRI) with reported GCH. They found 42 GCHs identified in 41 patients, and hemangiomatosis was present in 18 of 41 patients (44%). The extent of liver tissue involved by hemangiomatosis was variable but was confined to the same lobe as the GCH in the majority of patients (13/18).

As previously explained, enucleation is preferred when feasible for symptomatic GCH[10]. However, for GCH coexistent with DHH around the hemangioma, surgical candidates must be carefully selected to avoid surgical complications related to excessive blood loss from oozing due to the deroofing of the areas of hemangiomatosis after the enucleation of a GCH[5]. These cases can be better managed by extensive lobectomy, as the GCH may have small hemangiomatous lesions around the hemangioma, and large surgical margins are needed. When the tumor exceeds a certain volume in patients with limited hepatic reserve, liver resection is precluded. Liver transplantation should be considered for nonresectable benign hepatic neoplasms in patients with imminent life-threatening complications, an underlying liver disease, or the presence of severe symptoms[11]. In current published literature, there have been a total of 6 reported cases of GCH with DHH undergoing surgical intervention. In these 6 cases, 5 GCHs with DHH around the hemangioma underwent enucleation (one case)[3], extensive lobectomy (three cases)[12-14], and liver transplantation (one case)[11] respectively. Only one giant hepatic hemangioma was accompanied by DHH distributed throughout the liver, which received liver transplantation (Table 1)[15]. In fact, liver transplantation should be considered for hepatic hemangioma with DHH distributed throughout the entire liver. For hepatic hemangioma with DHH around the hemangioma, the target of treatment is the hemangioma. However, hemangiomatosis adjacent to the hemangioma does not require intervention.

Table 1 Retrievable reports on surgical treatment of giant cavernous hemangioma coexistent with diffuse hepatic hemangiomatosis.

Year	Clinical features	The largest GCH location	The largest GCH size, cm	DHH distribution	Treatment	Operation time, minutes	Intraoperation blood loss, mL	Postoperative length of stay, days	Follow up	Prognosis
2000	Post-prandial epigastric discomfort	Right lobe	17 × 14 × 9	Locally	Right hepatectomy	NA	NA	14	9 months	No recurrence
2014	Epigastric pain and abdominal fullness	Right lobe	20 × 14 × 8.5	Locally	Extensive right hepatectomy	190	845	9	NA	NA
2018	Abdominal pain, hepatomegaly	Central portion of the liver	16	Locally	Liver transplantation	575	1100	11	1.5 year	No recurrence
2020	NA	Segment IVb	7.8	Locally	Left hepatectomy	NA	NA	12	1 year	No recurrence
2021	Abdominal pain and distension	Segment IV	32 × 23 × 20	Throughout the liver	Liver transplantation	660	3000	16	6 months	No recurrence
2022	Right upper quadrant fullness	Left lobe	11 × 8 × 11.3	Locally	Enucleation	NA	NA	5	6 months	No recurrence

No Complication was observed in these cases. GCH: Giant cavernous hemangioma; DHH: Diffuse hepatic hemangiomatosis; NA: Not available.

In recent years, thermal ablation techniques, including RF ablation and MW ablation, have gained prominence in the treatment of hepatic hemangiomas due to advantages, such as minimal invasiveness, high efficacy, safety, rapid recovery, and broad applicability[1]. RF and MW ablation utilize heat generated by high-frequency alternating current or electromagnetic waves to disrupt endothelial cell-lined vascular structures, promoting thrombosis, inducing necrotic coagulation, destroying erythrocytes, and causing vascular smooth muscle cell loss and fibrosis in the ablated zone[16]. MW ablation offers certain advantages over RF ablation, including the creation of a larger necrotic area of necrosis, shorter treatment times, and reduced sensitivity to the conductivity of surrounding tissues caused by the heat-sink effect[17]. Success in this study relied on extensive experience, adherence to detailed treatment protocols, precise imaging guidance, and accurate antenna placement[18]. The puncture direction of the MW ablation antenna should be as parallel as possible to significant intrahepatic tracts. Additionally, when the MW antenna is positioned more than 2.0 cm away from hepatic vessel, vascular cooling effects help safeguard peritumoral vessels from damage[1]. Direct puncturing of normal liver parenchyma by the MW antenna should be avoided. After each ablation, the antenna is repositioned to target areas using the overlapping ablation method, particularly for large tumors[18]. Real-time visualization of the antenna trajectory is critical to prevent damage to bile ducts and hepatic vessels. Ablation is halted when microbubbles form near the antenna tip in proximity to major vessels or bile ducts, as monitored by intraoperative US guidance. Routine postprocedural imaging, alongside close monitoring of blood counts, coagulation profiles, hepatorenal function tests, and urine analysis, is strongly recommended[19]. Following ablation, the edge of the ablation zone shifted farther from peritumoral vessels due to tumor volume reduction, contributing to the alleviation of clinical symptoms[2]. In addition, all operators were required to observe MW ablation performed in a minimum of 10 patients at a center with more experience prior to commencing MW ablation at their own institution, which may provide the critical threshold knowledge to master the MW ablation technique. And many of the smaller centers were required to perform MW ablation only in straightforward cases, and refer more difficult cases to the larger centers.

Herein, we report two patients with GCH coexistent with DHH successfully treated by laparoscopic MW ablation. The two patients presented without severe complications during hospitalization and were in generally good condition, thus qualifying for thermal ablation. Protruding hemangiomas and superficial hemangiomas are indications for laparoscopic thermal ablation[18]. Therefore, a laparoscopic MW ablation procedure was employed in our two cases. Due to DHH within the liver parenchyma, it was left in situ without ablation to preserve liver parenchyma. It is worth noting that, due to the perivenous hemangioma in case 2, even though the tumor is larger, we aimed to minimize the ablation time and the number of ablation sessions in order to protect the surrounding normal tissue.

To the best of current knowledge, this report is the first to investigate the safety and efficacy of thermal ablation for GCH coexisting with DHH. In the study, both patients underwent successful MW ablation. Complete ablation of the hemangiomas was achieved, and the ablated zones demonstrated significant atrophy. Notably, follow-up imaging revealed a gradual reduction and eventual diminishment of DHH. Compared to surgical therapies described in previous literature, MW ablation was associated with reduced intraoperative bleeding and a shorter postoperative hospital stay, although no statistical comparisons were performed. Both patients were discharged shortly after the procedure without any symptoms or complications. The postoperative course was uneventful, with no recurrence of liver lesions detected during follow-up. It is important to note that this report specifically addresses cases involving thermal ablation for DHH located in proximity to GCH. Further clinical studies are needed to confirm the efficacy of thermal ablation for GCH combined with diffusely distributed DHH throughout the liver.

CONCLUSION

In conclusion, we reported two patients with GCH coexistent with DHH successfully treated by laparoscopic MW ablation. Thermal ablation treatment may be an effective and less invasive treatment for GCH coexistent with DHH around the hemangioma.

ACKNOWLEDGEMENTS

The authors would like to thank each of the investigators who contributed to this article.