Intravascular Papillary Endothelial Hyperplasia in Hypopharynx: A Case Report

Article information

J Korean Soc Laryngol Phoniatr Logop. 2024;35(2):75-78

Publication date (electronic) : 2024 August 30

doi : https://doi.org/10.22469/jkslp.2024.35.2.75

Jeong-In Jang¹, Jinwon Seo², Jeong Wook Kang^,1

¹Department of Otorhinolaryngology-Head and Neck Surgery, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea

²Department of Pathology, Hallym University Sacred Heart Hospital, Anyang, Korea

Corresponding Author Jeong Wook Kang, MD Department of Otorhinolaryngology-Head and Neck Surgery, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, 22 Gwanpyeong-ro 170beon-gil, Dongan-gu, Anyang 14068, Korea Tel +82-31-380-3840 Fax +82-31-386-3860 E-mail simbody@naver.com

Received 2024 April 9; Revised 2024 July 17; Accepted 2024 August 8.

Abstract

INTRODUCTION

Masson’s hemangioma, also known as intravascular papillary endothelial hyperplasia (IPEH), is a rare benign vascular tumor [1]. It was first described by Masson in 1923, and has been known by various names, with IPEH being the preferred term [1,2]. IPEH is characterized by the proliferation of endothelial cells within blood vessels, often surrounding a thrombus [3]. This lesion typically presents as a reddish-blue firm mass, commonly occurring in the head, neck, and extremities, but can affect various body parts [4]. Clinically, it may resemble more aggressive vascular lesions such as angiosarcomas, necessitating accurate diagnosis to avoid unnecessary aggressive treatment [5]. Despite its benign nature, its rarity and potential for misdiagnosis indicate the importance of awareness and careful histopathological examination in its management.

IPEH in the hypopharynx is uncommon, with only once case reported in the English-language medical literature [6]. Herein, we present the case of a patient with hypopharyngeal IPEH and discuss its pathogenesis, pathologic features, and management.

CASE REPORT

A 76-year-old male presented with gradually worsening intermittent oral bleeding and dysphagia. The symptoms had appeared several months prior, initially as a globus, and subsequently advanced to bleeding and dysphagia. One month prior, he had experienced bleeding from the mouth, with no accompanying symptoms such as weight loss or sore throat.

The patient had not been diagnosed with any malignancy. However, he reported a history diabetes and hypertension; therefore, he was receiving antiplatelet treatment. The patient had a record of alcohol consumption and 25 pack-years of smoking. He reported no familial history of genetic diseases, tumors, or mental illnesses.

Laryngoscopy revealed a protruding tumor on the posterior hypopharyngeal wall. The mass was approximately 2-cm long and fixed to the retropharynx (Fig. 1A). Its surface was irregular, reddish blue in color, and slightly hemorrhagic. Liver function tests revealed elevated aspartate transaminase (43 IU/L) and alanine transferase (70 IU/L) levels as well as prolonged bleeding time. Hemoglobin was within the normal range at 17.6 g/dL. However, other hematological parameters, kidney function, electrolytes, urinalysis, coagulation function, and infectious disease screening revealed no significant abnormalities. Cervical computed tomography (CT) revealed a 1.9×1.7 cm soft tissue mass in the middle of the posterior hypopharyngeal wall, near the upper esophageal sphincter (Fig. 2). This mass exhibited slight heterogeneous contrast enhancement.

Fig. 1.

Laryngoscopy findings. A: Preoperative image, the hypopharyngeal mass presented a firm, irregular-shaped soft tissue mass with a reddish-blue hue. B: Postoperative image.

Fig. 2.

Post-contrast neck computed tomography findings. The axial (A) and sagittal plane (B) display a 19×17×9 mm irregular-shaped heterogeneous soft tissue mass in the posterior hypopharyngeal wall, indicated by red arrowheads.

After radiological evaluation, the patient underwent laryngeal microscopic surgery under general anesthesia. Given the endoscopic appearance and CT findings suggesting the possibility of malignancy, we considered the potential need for a frozen biopsy and wide excision during surgery. However, since hemangioma was not strongly suspected, preoperative embolization was not performed. During the excision of the hypopharyngeal tumor with a CO₂ laser via suspension laryngoscopy, bleeding was minimal and was effectively controlled using defocusing laser coagulation under microscopic guidance without acute complication. The intraoperative frozen biopsy revealed benign pathology, so additional wide excision was not performed. Postoperatively, the patient did not require an extended period of fasting and began a soft diet four hours after general anesthesia recovery.

The excised tissue was histopathologically evaluated. Histopathology revealed increased vasculature (Fig. 3). The endothelial cells formed numerous papillary projections within the vascular lumen. An enlarged, endothelial cell-lined vascular space, characterized by numerous interconnecting channels was observed. The papillary formations extended into the vessel lumen. No significant increase in mitotic activity was observed. Angiosarcoma was ruled out due to the absence of dysplasia in the endothelial lining. However, no thrombus was apparent within the blood vessel lumen. Additionally, immunohistochemical staining for CD31 and CD34 yielded positive findings. Therefore, the final pathological diagnosis was IPEH of the posterior hypopharyngeal wall.

Fig. 3.

Histopathological findings. Intravascular papillary endothelial hyperplasia is a well-circumscribed reactive lesion characterized by papillary fronds lined by a single layer of endothelial cells (arrowheads), proliferating within a vascular lumen (Rhombus). A single layer of banal-appearing flat cells wraps around the fibrotic core (star). Papillary fronds (arrow) are lined by a single layer of endothelial cells (hematoxylin and eosin stain, ×100).

The patient was followed-up for 1 year, by which point all symptoms subsided, with no evidence of local recurrence (Fig. 1B).

DISCUSSION

Diagnosing IPEH in the hypopharynx is particularly challenging and differs from cases in other parts of the body. In our case, a biopsy was performed under general anesthesia. This approach is necessary because fiberoptic endoscopic biopsies in the hypopharynx without general anesthesia can result in severe bleeding, leading to aspiration or respiratory issues. Additionally, the endoscopic appearance of IPEH in our case closely resembled that of a malignant tumor. These factors show the unique challenges and clinical significance of our case, which are not commonly seen in other reports of IPEH. Our case emphasizes the need to consider IPEH when diagnosing hypopharyngeal masses to avoid misdiagnosis and ensure proper treatment.

IPEH is a relatively rare condition with a slight female predilection and can occur in any body part, though it is more common in the head, neck, fingers, and trunk [7,8]. The pathogenesis is thought to involve the organization of a thrombus, providing a framework for endothelial cell proliferation and papillary formation [7,9-11]. There are three types of IPEH: primary, secondary (or mixed), and extravascular, each associated with different clinical settings [7].

Histopathologically, IPEH is characterized by papillary proliferation of vascular endothelial cells [5]. Endothelial cells are typically identified using immunohistochemical markers such as CD31, CD34, or factor VIII [12]. It is important to distinguish IPEH from more aggressive lesions like angiosarcoma. Key distinguishing features include the confinement of the lesion within a vessel, frequent association with thrombus formation, lack of significant cellular atypia, and absence of necrosis and low mitotic activity [12]. Misdiagnosing IPEH as angiosarcoma can lead to unnecessarily aggressive treatments.

IPEH is rarely known to undergo malignant transformation. However, in clinical practice, angiosarcoma and IPEH can appear similar upon gross examination. Differentiating between malignant tumors and IPEH based solely on gross findings is challenging. Therefore, a thorough histopathological analysis is essential for accurate diagnosis. Nonetheless, the possibility of malignancy should be considered if the gross findings reveal extensive necrotic tissue, poorly defined tumor margins, or an invasive pattern disrupting normal anatomical structures.

The primary treatment for IPEH is complete surgical excision, which is usually curative. In some cases, particularly those involving the mixed form of IPEH, preoperative embolization may be used to reduce bleeding during surgery [12]. Recurrence is rare with proper excision, though regular follow-up is necessary, especially in cases of incomplete excision.

In our case, the endoscopic findings did not strongly suggest the possibility of hemangioma, so we did not perform preoperative embolization. Instead, the initial assessment indicated a higher probability of malignancy, particularly hypopharyngeal cancer, based on the laryngoscopic findings. The neck CT scan also suggested a high possibility of hypopharyngeal cancer. Consequently, we performed surgery with the consideration of a potential wide excision following intraoperative frozen section analysis. The frozen section analysis revealed benign pathology, so only a simple excision was performed. Similar to the general prognosis for IPEH, our patient did not experience recurrence during the one-year follow-up period after excision.

In conclusion, considering IPEH as a differential diagnosis for hypopharyngeal vascular lesions is crucial for appropriate management and to avoid misdiagnosis.

Article information Continued