Intravascular papillary endothelial hyperplasia (Masson lesion) of the hypopharynx and larynx.
Masson lesion is characterized by a benign intravascular papillary hyperplasia and subsequent thrombosis. Clinically, this lesion can be misdiagnosed as mucocele, hemangioma, Kaposi sarcoma, angiosarcoma, pyogenic granuloma, and several other lesions. In this article, we report a case of intravascular papillary endothelial hyperplasia of the hypopharynx and larynx, which caused dysphagia in an 18-year-old female patient. The lesion was excised entirely via a lateral pharyngotomy approach. We discuss the clinical and histopathologic features, differential diagnosis, and treatment of this uncommon entity.
In 1923, Masson first described a benign intravascular lesion consisting of intravascular papillary hyperplasia and secondary thrombosis. (1) He introduced the term vegetant intravascular hemangioendothelioma, but intravascular angiomatosis, intravenous pyogenic granuloma, Masson disease, intravenous papillary endothelial hyperplasia, and intravenous vascular proliferation are the other synonyms used to describe this lesion.
Clinically, intravascular papillary endothelial hyperplasia (IPEH) often presents as a subcutaneous or submucous red-blue mass. Skin lesions are mostly encountered in the head and neck region. The diagnosis might be controversial, and IPEH can be mistaken for mucocele, hemangioma, Kaposi sarcoma, angiosarcoma, pyogenic granuloma, and several other lesions. Recurrence after total excision is extremely rare. (2)
An 18-year-old female patient came to our institution with a complaint of dysphagia of 1 1/2 months' duration. Her medical history was unremarkable. On physical examination, her oropharynx was found to be normal. A reddish-blue mass, vascular in appearance, involving the right pyriform sinus and aryepiglottic fold, and protruding into the laryngeal ventricle was detected on endoscopic examination. Magnetic resonance imaging (MRI) showed a vascular mass obliterating the right pyriform sinus (figure 1) and extending to the laryngeal ventricle (figure 2). The mass was removed in its entirety via a lateral pharyngotomy approach. The patient's postoperative course was without complication, and she was discharged 5 days after the operation. Histopathologic examination of the mass revealed IPEH (figure 3). Two weeks after surgery, her dysphagia had resolved.
IPEH is a relatively rare lesion that occurs in the fingers, head and neck, trunk, lower extremities, and upper extremities, in order of decreasing frequency. (3) IPEH also may involve the pharynx, buccal mucosa, lips, mouth, tongue, masseter muscle, and parotid gland. (2,4) Although the larynx and hypopharynx are rarely affected, extravascular papillary endothelial hyperplasia of the larynx has been reported. (5) The average age of affected patients is stated to be 40 years, but the age distribution can vary from 9 months to 80 years. (2,4) Although a slight female preponderance has been reported, both sexes are almost equally affected. (2,4)
Three forms of IPEH have been described. A pure, or primary, form arises within dilated vascular space; a mixed, or secondary, form occurs within a preexisting vascular lesion, such as a hemangioma or pyogenic granuloma; and a rare, extravascular form arises in a hematoma. (6) Development of a true neoplasm with secondary thrombosis, a reactive process possibly due to trauma, or an unusual thrombus organization have been suggested for the pathogenesis of IPEH. (2)
The differential diagnosis is important because IPEH can be mistaken for several other lesions. Clinically, IPEH can be misdiagnosed as a mucocele, hemangioma, pyogenic granuloma, Kaposi sarcoma, angiosarcoma, Kimura disease, intravenous atypical vascular proliferation, endovascular papillary angioendothelioma, papular angioplasia, or bacillary angiomatosis. (1,2,7)
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Radiologically, IPEH is contrast-enhancing and homogenous on computed tomography (CT) or MRI and might contain microcalcification areas. Hemangiomas, hematomas, or tumors may also contain microcalcification areas. On angiography, IPEH can manifest as a vascular or avascular mass. (2) Thus, there are no specific findings for IPEH on CT, MRI, or angiography.
Histopathologic examination is the mainstay of differential diagnosis. Histologically, bundles of papillae with single or several stalks presenting in a dilated vascular space, projecting and even occluding the lumen, are the main features of IPEH. (1) Angiosarcoma is differentiated by its invasive pattern, increased mitotic activity, necrotic loci, and cellular pleomorphism. The pyogenic granuloma is mostly found on the gingiva, but it also can affect the lips, buccal mucosa, and tongue. This lesion is characterized by a pedunculated mass with a smooth, verrucous surface and may become hemorrhagic. Endothelial cells are prominent features in both pyogenic granuloma and IPEH, but in the latter no surrounding vascular wall is evident.
Clinically, Kaposi sarcoma can be detected in the oral cavity, palate, or tongue as a reddish-brown or blue, flat, vascular lesion, and it may mimic IPEH. Histopathologically, characteristic features of Kaposi sarcoma include anastomosing slit-like vessels with a fascicular pattern of spindle-shaped cells, capillary proliferation, hemosiderin pigment deposition, and plasma-cell infiltration.
Hemangiomas can be differentiated from IPEH by their lack of endothelial proliferation unless they are secondarily traumatized. Endovascular papillary angioendotheliomas are histologically similar to IPEH, but they can be differentiated by their more columnar endothelial cells and their lymphatic component. Mucoceles may resemble IPEH clinically when they present as a bluish raised mass on the lower lip, floor of the mouth, or tongue. However, these lesions are easily distinguished microscopically, as they are seen as a cavity consisting of fibrous connective tissue and fibroblasts, and containing eosinophilic coagulum.
In conclusion, IPEH may clinically and radiologically mimic several other lesions. Histopathologic examination is required to confirm the diagnosis. When IPEH is located in the supraglottic larynx and hypopharynx, as in our patient, the initial symptom might be dysphagia. The treatment of choice for this benign lesion is surgical removal. Recurrence is extremely rare.
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(1.) Lancaster JL, Alderson DJ, Sherman IW, Clark AH. Papillary endothelial hyperplasia (Masson's tumour) of the maxillary sinus. J Laryngol Otol 1998;112(5):500-2.
(2.) Pantanowiz L, Muc R, Spanger M, et al. Intravascular papillary endothelial hyperplasia (Masson's tumor) manifesting as a lateral neck mass. Ear Nose Throat J 2000;79(10):806, 809-10,812.
(3.) Hong SG, Cho HM, Chin HM, et al. Intravascular papillary endothelial hyperplasia (Masson's hemangioma) of the liver: A new hepatic lesion. J Korean Med Sci 2004;19(2):305-8.
(4.) Luce EB, Montgomery MT, Redding SW, Aufdemorte TB. Intravascular angiomatosis (Masson's lesion). J Oral Maxillofac Surg 1988; 46(9):736-41.
(5.) Sezgin S, Kotiloglu E, Kaya H, Inanli S. Extravascular papillary endothelial hyperplasia of the larynx: A case report and review of the literature. Ear Nose Throat J 2005;84(1):52-3.
(6.) Hashimoto H, Daimaru Y, Enjoji M. Intravascular papillary endothelial hyperplasia. A clinicopathologic study of 91 cases. Am J Dermathopathol 1983;5(6):539-46.
(7.) Manivel JC, Wick MR, Swanson PE, et al. Endovascular papillary angioendothelioma of childhood: A vascular lesion possibly characterized by "high" endothelial cell differentiation. Hum Pathol 1986;17(12):1240-4.
M. Guven Guvenc, MD; Levent Derekoylu, MD; Nazim Korkut, MD; Ferhan Oz, MD; Buge Oz, MD
From the Department of Otorhinolaryngology and Head and Neck Surgery (Dr. Guvenc Dr. Derekoylu, Dr. Korkut, and Dr. F. Oz) and the Department of Pathology (Dr. B. Oz), Istanbul University, Cerrahpasa Medical Faculty, Istanbul, Turkey.
Corresponding author: M. Guven Guvenc, MD, Oguzhan Cad, Ugurpalas Ap. No: 21/534270 Findikzade/Istanbul, Turkey. Phone: 90-5326028424; fax: 90-2124143408; e-mail: email@example.com