|Year : 2021 | Volume
| Issue : 1 | Page : 70-72
Lipomatous hemangiopericytoma of the larynx: An extremely rare tumor at an unusual location
Kanika Singh, Mukta Pujani, Avani Jain, Aparna Khandelwal
Department of Pathology, ESIC Medical College, Faridabad, Haryana, India
|Date of Submission||07-Sep-2020|
|Date of Decision||06-Oct-2020|
|Date of Acceptance||07-Oct-2020|
|Date of Web Publication||26-Mar-2021|
Department of Pathology, ESIC Medical College, Faridabad, Haryana
Source of Support: None, Conflict of Interest: None
Hemangiopericytoma (HPC) arising from the contractile pericyte of Zimmerman comprises less than 1% of the vascular tumors with approximately 200 cases documented in the literature, out of which only 11 cases are reported in the larynx. Lipomatous hemangiopericytoma (LHPC) is an uncommon histological variant composed of a mixture of HPC and mature lipomatous component with around 50 cases reported so far, and majority have been found in the deep soft tissue of the lower extremities and retroperitoneum. HPCs are closely related to solitary fibrous tumors, and the LHPC was designated as a separate entity according to recent the World Health Organization classification of soft tissue tumors in 2002. To the best of our knowledge, even on extensive search of literature, LHPC of the larynx has not been reported till date. We report an extremely rare case of LHPC in a middle-aged female presented with a mass in the arytenoid cartilage of the larynx.
Keywords: Hemangiopericytoma, larynx, lipomatous hemangiopericytoma, solitary fibrous tumor
|How to cite this article:|
Singh K, Pujani M, Jain A, Khandelwal A. Lipomatous hemangiopericytoma of the larynx: An extremely rare tumor at an unusual location. Saudi J Health Sci 2021;10:70-2
|How to cite this URL:|
Singh K, Pujani M, Jain A, Khandelwal A. Lipomatous hemangiopericytoma of the larynx: An extremely rare tumor at an unusual location. Saudi J Health Sci [serial online] 2021 [cited 2022 Sep 28];10:70-2. Available from: https://www.saudijhealthsci.org/text.asp?2021/10/1/70/311959
| Introduction|| |
The common vasoformative tumors of the head and neck region include hemangiopericytoma (HPC), angiosarcoma, and Kaposi's sarcoma. The mesenchymal tumors of the larynx are extremely rare. The histological and clinical behavior of HPC and solitary fibrous tumor (SFT) is similar, and therefore, according to the World Health Organization (WHO), a unifying term “HPC/SFT” was proposed in 2006. SFT was first described by Dr. Klemper in the pleura in 1931. They have also been identified outside the pleura where the term extrapleural or extrathoracic SFT is used. HPC comprises less than 1% of the vascular tumors and arises from the contractile pericyte of Zimmerman, and around 15%–25% of HPC occurs in the head and neck region. It was first described by Stout and Murray in 1942.
SFT has been described in almost every organ, but only seven cases have been reported so far in the larynx. It is usually a slow-growing benign tumor and rarely malignant. The diagnosis is based on the architectural, cytomorphological, and immunohistochemical features. Lipomatous hemangiopericytoma (LHPC) is an uncommon variant composed of a mixture of HPC and mature lipomatous component. It was first described by Theunissen et al. in 1990 and so named by Nielson et al. in 1995. LHPC has been reclassified as fat-forming SFT by the WHO in 2013. There have been approximately 50 cases reported in the literature so far, and majority are found in the deep soft tissue of the lower extremities and retroperitoneum. On extensive search of the literature, none of the cases have been found in the larynx.
Here, we report an extremely rare case of LHPC in a middle-aged female presented with a polypoidal mass in the larynx at the arytenoid cartilage.
| Case Report|| |
A 37-year-old female presented with chief complaint of difficulty in swallowing for the past 7 months. Laryngoscopy was performed which revealed a smooth round submucosal mass with the greatest dimension of 13 mm with prominent vascularity arising from the left arytenoid, leading to luminal narrowing. Computed tomographic findings showed an enhancing polypoidal mass occluding the laryngeal space. There was no extension or destruction of the other laryngeal structures; however, there was significant occlusion. The other parameters were within normal limits, and no palpable neck lymph nodes or nodes at any other site were found. A biopsy was taken from the mass lesion.
The histopathology revealed tumor tissues composed of multiple endothelial lined branching capillaries (Staghorn pattern) and cellular areas comprising spindle cells surrounding the vessels with no definite pattern. The spindle cells had bland vesicular nuclei with inconspicuous nucleoli. Mature adipose tissue was admixed with few myxoid and HPC-like areas. The nuclear atypia and mitosis were not present, and no necrosis or lymphovascular invasion was noted.
The immunohistochemistry showed that the tumor cells were diffusely positive for CD34, vimentin, and smooth muscle actin.
A diagnosis of LHPC was given based on the histological features and immunohistochemical findings.
| Discussion|| |
The classic SFT of the head and neck region constitutes ~ 6% of all SFTs. The neoplasm is extremely rare in the larynx. It can be seen at all ages; however, the mean age of presentation is 46.7 years. The patients may present with hoarseness of voice, foreign body sensation, breathing difficulty, or changes in phonation. In the present case, the patient was a middle-aged female of 37 years who presented with difficulty in swallowing.
LHPC, an uncommon variant of HPC, was first described by Theunissen et al. in 1990 and the name was given by Nielson et al. in 1995. It is composed of mature adipose tissue and HPC-like areas. Guillou et al. studied the morphological, immunohistochemical, and ultrastructural features in a series of 13 cases and suggested that LHPC represents a fat containing variant of solitary fibrous tumor and not a separate entity.
Grossly, LHPC usually presents as a well-demarcated medium-sized mesenchymal tumor which is variably encapsulated. The cut sections of the tumor show a lobular or fascicular appearance with alternating whitish and yellowish areas. Microscopically, a varying combination of cellular areas consisting of round to spindle cells along with myxoid or collagenous tissue with focal sclerosis was noted. The areas corresponding to HPC consisted of thick-walled small to medium sized branched vessels admixed with lipomatous region comprising mature adipose tissue [Figure 1].
|Figure 1: Section showing tumor composed of multiple endothelial lined branching capillaries (Staghorn pattern) and cellular areas comprising spindle cells admixed with lipomatous areas (a, H and E, ×40); (b) at high power (H and E, ×100)|
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The histopathological features of malignancy are increased cellularity, pleomorphism, high mitosis (4 mitosis/10 high-power field), necrosis, and nuclear pleomorphism., In the present case, no such features were identified, pointing toward a benign tumor.
The differential diagnosis includes other soft tissue tumors such as liposarcoma and spindle cell lipoma. The myxoid variant of liposarcoma may have a prominent vasculature where the vessels demonstrate a delicate plexiform capillary vascular network in contrast to the Staghorn pattern in the case of HPC with the absence of lipoblasts. According to Weiss' criteria, a lipoblast must demonstrate “a hyperchromatic indented or scalloped nucleus, lipid-rich (neutral fat) droplets in the cytoplasm, and an appropriate histologic background.” which is helpful in differentiating multivacuolated fat containing cells (lipoblast-like cell). The normal fat entrapment in the tumor can be excluded by the presence of a pseudocapsule and its presence throughout the tumor tissue which was seen in our case where the adipocytes were seen admixed with the tumor cells at several places within the tumor.
The immunohistochemical staining may be helpful in the diagnosis. The nonadipocytic tumor cells stain positive for CD99, CD34 (75%), and Bcl-2 (60%). Reticulin stain may also be helpful where individual cells are seen surrounded by reticulin which is seen in our case illustrated in [Figure 2]. In our case, the tumor cells were diffusely positive for vimentin, smooth muscle actin, and CD34 [Figure 2]. Thus, on the basis of histological and immunohistochemical analysis, a diagnosis of LHPC was rendered in the present case. The molecular diagnosis is possible by detection of STAT6-NAB2 gene fusion product, which is highly specific and sensitive, and can be demonstrated by PCR in 91% of cases of SFT.
|Figure 2: Section showing individual tumor cells surrounded by reticulin fibers (reticulin stain, ×100); tumor cells are diffusely positive for CD34 and vimentin (IHC, ×40)|
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LHPC is a slow-growing benign mesenchymal neoplasm with low rates of local recurrence after excision. A complete surgical excision is the mainstay of treatment. The CO2 laser surgery is being used as a modality as the neoplasm is highly vascular. The recurrence has not been reported in LHPC; however, a close clinical follow-up is warranted as little is known about the behavior of these tumors in the larynx due to a paucity of data.
| Conclusion|| |
LHPC is an extremely rare clinical and pathological entity in the larynx. It is composed of benign HPC-like areas and mature adipose tissue. Most of these tumors behave in a benign fashion; however, it is known for recurrence. It is essential for the clinicians, radiologists, and pathologists to have knowledge about this entity and the possibility of its occurrence at rare sites such as larynx for the proper evaluation and management of the patient.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]