Abstract
Malignant peripheral nerve sheath tumors are highly aggressive tumors and they arise either de novo or from preexisting benign schwannoma or neurofibromatosis. Malignant peripheral nerve sheath tumor of the larynx is an extremely rare neoplasm, for which accurate diagnosis is difficult and the therapy is usually delayed. Although wide surgical excision is the mainstay of treatment, radiation therapy also plays an important role in the control and treatment of locally recurrent disease and non resectable cases. Here we are reporting a case of malignant peripheral nerve sheath tumor of the larynx without definite evidences of von Recklinghausen’s disease or preexisting benign peripheral nerve sheath tumor.
Keywords: Malignant peripheral nerve sheath tumor, Larynx
Case Summary
This 75 year old gentleman, with no history of any comorbidites, presented with complaints of hoarseness of voice, which he noticed for 2 month duration. General physical examination and systemic examinations were nothing contributory. He was evaluated and laryngoscopy was done which showed an ulcerated fleshy mass in the subglottic region, more towards the left side. CT of the neck (Fig. 1a) was taken for further evaluation, in which a minimally enhancing soft tissue thickening of size 1.5 × 1 cm was noted in the infraglottic region, more to the left side and extending to the anterior commissure with enlarged bilateral level 1b, 2 and level 5 lymphnodes. No luminal narrowing was noted. Biopsy was taken with help of VLS and tracheostomy was performed in view of possible stridor. Morphology and immunohistochemistry features (elevated S100) of the specimen was suggestive of Malignant peripheral nerve sheath tumor.
Fig. 1.
(a) CT scan of neck showing laryngeal lesion with minimal narrowing of lumen (red arrow). (b) Laryngectomy specimen with lesion marked using white arrow
As the metastatic workup was negative, decided to proceed with total laryngectomy. Intraoperatively, a greyish white ulceroproliferative mass of size 3 × 1.8 × 1 cm was noted, extending from supraglottic region to subglottic region (Fig. 1b). Laryngectomy was done and an end tracheostomy was created. Pathological examination showed neoplasm in the larynx, composed of spindle shaped cells arranged diffusely and in fascicles (Fig. 2a). Cells showed fusiform and ovoid vesicular hyperchromatic nuclei and distinct nucleoli with moderate cytoplasm. Tumor cells were showing positivity on S100 staining (Fig. 2b). Tumor was invading the thyroid and cricoids cartilage. There were of necrosis present within the tumor. All margins were free of tumor and there was no metastatic deposits in the lymphnodes. Post operative period was uneventful and patient was discharged with tracheostomy insitu with a plan for adjuvant radiotherapy during followup.
Fig. 2.
(a) (H&E, 10×) Showing hypercellular tumor with spindle cells arranged in fascicles. (b) (S100, 40×) Tumor cells showing positivity for S100
Discussion
MPNSTs are very rare tumors with an incidence of approximately 0.001% in the population [1]. They usually affect the proximal extremities and trunk and are very rare in the head and neck region. Very few cases of MPNST larynx have been reported in English literature. MPNSTs usually arise in adulthood, with most occurring in age around 20–50 years [1]. They can occur sporadically or more commonly as a consequence of malignant degeneration of a neurofibroma or schwannoma in patients with NF1 and the frequency of malignant conversion is reported to be approximately 3% to 30% [3].MPNSTs of larynx will have ambiguous clinical symptoms and non-specific radiographic findings, making the diagnosis very difficult and causes treatment delay in many cases. In patients with NF-1, these lesions are often misdiagnosed as neurofibroma and/or plexiform neurofibroma. Masses are the most common presentation and [2] non-specific pain or abnormal sensations in the area supplied by the nerves which are invaded by the tumor is also common. Some patients also develop symptoms of airway obstruction. MPNSTs can resemble benign tumors, both radiologically and histologically. To make an early diagnosis of MPNST, evaluation by magnetic resonance imaging and a biopsy should be performed.
MRI can reveal the nerve of origin and it’s more accurate to evaluate the topographical relationship of the tumour with neighboring vascular structures, muscular structures and fat planes involvement. CT scan is useful to assess the tumour extension as well as metastasis. The most common metastatic sites are the lungs. They are also seen in bone, liver and soft tissues [3]. Histological features are those of a highly cellular spindle cell neoplasm, resembling a soft tissue sarcoma but with differentiation towards elements of nerve sheath, Schwann cells and perineural cells. Frequent mitosis and focal necrosis are typical for MPNSTs [4]. Similar to most the soft-tissue sarcomas, surgery is the mainstay of treatment for MPNSTs of the head and neck, with complete surgical excision of the tumor with negative margins correlating with longer overall survival [5]. But due to the relatively small space within the head and neck, the proximity of the tumor to the vital structures, and the risk of microscopic local spread, obtaining negative margins may be difficult. These factors will lead to high rates of local recurrence (22–52%) and distant metastasis (18–33%) and thus a multimodality treatment approach is most favorable for treatment of MPNSTs of head and neck [5, 6]. Many studies have cited the importance of radiotherapy as adjunctive treatment, in addition to surgery, especially for improving the local control [5, 6]. The radiation dose commonly administered in cases of head and neck MPNSTs is 50–60 Gy. As part of a uniform treatment policy for MPNSTs, the oncology consensus group has recommended adjuvant radiotherapy for all “intermediate- to high-grade lesions and for low-grade tumors after a marginal excision” [7]. Although the consensus group states that radiotherapy will provides local control only and has limited effect on long-term survival, some more recent studies have reported survival benefit for it [5, 6].
Conclusion
Though very rare, a suspicion of malignant peripheral nerve sheath tumour should also be kept in mind while dealing with a case of laryngeal mass. Diagnosis is made by a combining of clinical, radiological and pathological features. Early surgical resection followed by radiotherapy is the preferred mode of treatment for MPNSTs of head and neck.
Author Contributions
All authors were involved in the clinical care of the patient. All authors have read and approved the manuscript.
Funding
None.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflicts of interest.
Footnotes
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References
- 1.Weiss SW. Enzinger and Weiss’s soft tissue tumors. St. Louis: Mosby; 2001. Benign tumors of peripheral nerves; pp. 1111–1207. [Google Scholar]
- 2.Gupta TD, Brasfield RD. Solitary malignant schwannoma. Ann Surg. 1970;171(3):419. doi: 10.1097/00000658-197003000-00016. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Ducatman BS, Scheithauer BW, Piepgras DG, Reiman HM, Ilstrup DM. Malignant peripheral nerve sheath tumors. A clinicopathologic study of 120 cases. Cancer. 1986;57(10):2006–2021. doi: 10.1002/1097-0142(19860515)57:10<2006::AID-CNCR2820571022>3.0.CO;2-6. [DOI] [PubMed] [Google Scholar]
- 4.Chitale AR, Dickersin GR. Electron microscopy in the diagnosis of malignant schwannomas a report of six cases. Cancer. 1983;51(8):1448–1461. doi: 10.1002/1097-0142(19830415)51:8<1448::AID-CNCR2820510819>3.0.CO;2-P. [DOI] [PubMed] [Google Scholar]
- 5.Anghileri M, Miceli R, Fiore M, Mariani L, Ferrari A, Mussi C, Lozza L, Collini P, Olmi P, Casali PG, Pilotti S. Malignant peripheral nerve sheath tumors: prognostic factors and survival in a series of patients treated at a single institution. Cancer. 2006;107(5):1065–1074. doi: 10.1002/cncr.22098. [DOI] [PubMed] [Google Scholar]
- 6.L’Heureux-Lebeau B, Saliba I. Updates on the diagnosis and treatment of intracranial nerve malignant peripheral nerve sheath tumors. Onco Targets Ther. 2013;6:459. doi: 10.2147/OTT.S41397. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Ferner RE, Gutmann DH. International consensus statement on malignant peripheral nerve sheath tumors in neurofibromatosis. Cancer Res. 2002;62:1573–1577. [PubMed] [Google Scholar]