Kaposiform hemangioendothelioma in tonsil of a child associated with cervical lymphangioma: a rare case report

Abstract

Kaposiform hemangioendothelioma (KHE) is an uncommon vascular tumor of intermediate malignant potential, usually occurs in the extremities and retroperitoneum of infants and is characterized by its association with lymphangiomatosis and Kasabach-Merritt phenomenenon (KMP) in certain cases. It has rarely been observed in the head and neck region and at times, can present without KMP. Herein, we present an extremely uncommon case of KHE occurring in tonsil of a child, associated with a neck swelling, but unassociated with KMP. A 2-year-old male child referred to us with history of sore throat, dyspnoea and right-sided neck swelling off and on, since birth, was clinicoradiologically diagnosed with recurrent tonsillitis, including right sided peritonsillar abscess, for which he underwent right-sided tonsillectomy, elsewhere. Histopathological sections from the excised tonsillar mass were reviewed and showed a tumor composed of irregular, infiltrating lobules of spindle cells arranged in kaposiform architecture with slit-like, crescentic vessels. The cells displayed focal lumen formation containing red blood cells (RBCs), along with platelet thrombi and eosinophilic hyaline bodies. In addition, there were discrete foci of several dilated lymphatic vessels containing lymph and lymphocytes. On immunohistochemistry (IHC), spindle cells were diffusely positive for CD34, focally for CD31 and smooth muscle actin (SMA), the latter marker was mostly expressed around the blood vessels. Immunostaining for HHV8 was negative and Ki-67 (proliferation marker) displayed focal positivity. Diagnosis of KHE was made. Platelet count was towards lower side of range. Postoperative imaging showed discrete, multiple fluid containing lesions in the right neck that were high on T2-weighed sequences, on magnetic resonance imaging (MRI) and ipsilateral intraoral mucosal growth. Fine needle aspiration cytology (FNAC) smears from neck swelling showed blood, fluid and lymphocytes. Possibility of a coexisting lymphangioma was considered. The patient was offered sclerotherapy and is on follow-up. This case forms the second documented case of KHE at this site, along with its unique association with neck lymphangioma. KHE has distinct histopathological features and can be sorted out from its other differentials like juvenile hemangioma and Kaposi's sarcoma. IHC stains are useful in substantiating a definite diagnosis.

C-Kit, CD34 & α-SMA Immunohistochemical Features in Classic Kaposi Sarcoma and Kaposiform Hemangioendothelioma

“…However, the cause and significance of this phenotypic heterogeneity are unclear yet [ 47 ]. Similar to our findings in KHE, others [ 48 49 ] reported α-SMA expression by pericytes that outlines tumor spindle cells, but not by the spindle tumor cells of KHE.…”

Cytokeratin-positive epithelioid angiosarcoma presenting in the tonsil: a diagnostic challenge

“…All of these metastatic deposits were minute bleeding lesions, and none of them was compatible with a primary tumor. Rare low-grade variants of malignant vascular neoplasms reported as tonsillar or intraoral primary include epithelioid [14] and kaposiform [15] hemangioendothelioma. Both are low-grade vascular sarcomas that can be readily distinguished from epithelioid angiosarcoma by their characteristic histologic and clinicopathologic features.…”

Tonsillar malignancy in adult patients with peritonsillar abscess: retrospective study of 275 patients and review of the literature

“…Six patients are described in case reports [6,7,9,10,[12][13] and the remaining two in retrospective cohort series, including the present study [11]. To our knowledge, this study is the first to report on the prevalence of unsuspected tonsillar malignancy in a series of PTA patients only.…”

“…In agreement with other researchers, the possibility of PTA as an independent risk factor for tonsillar malignancy was questioned [1,3,10]. A literature search revealed several case reports on tonsillar malignancy presenting as PTA, which supported the concept that PTA may be associated with tonsillar malignancy [5][6][7][8][9][10][12][13][14]. Thus, clarification of whether PTA should be added to the list of risk factors indicating histological examination is warranted.…”

“…During a severe episode of throat pain, he was clinical and radiological diagnosed with PTA and underwent tonsillectomy. Malignancy was not suspected at the time of surgery, but histological review of the tonsillar specimen revealed Kaposiform hemangioendothelioma [13].…”