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An ntrathorac c schwannoma case n F-FDG PET/CT
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Hell J Nucl Med 2020; 23(2): 206-208 Published online: 24 August 2020
Figure 1. A 39-year-old male pat ent presented w th compla nts of ncreased dyspnea w th e ort. Computed tomography (CT) was performed to the pat ent. On CT, a mass was detected n the left lower lobe of super or segment, w th a pleural-based soft t ssue dens ty based on the poster or costovertebral groove. The mass was closely related
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to the thorac c aorta. It was dec ded to perform uor ne-18- uorodeoxyglucose ( F-FDG) pos tron em ss on tomography (PET)/CT to the pat ent w th susp c on of mal g-nancy.
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Pos tron em ss on tomography /CT mages showed a moderately ncreased F-FDG uptake n the mass of left lung lower lobe 18
super or segment (SUVmax: 2.71). No patholog cal F-FDG nvolvement was detected n another reg on of the whole body scan (F gure 1; black and wh te arrows). The pat ent underwent tru-cut b opsy. S nce h stopatholog cal d agnos s could not be made, thoracotomy was performed.
Figure 2. The mass located n the poster or med ast num of the pat ent was surg cally removed by thoracotomy (black arrows) and sent for h stopatholog cal exam nat on. Images
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Hellenic Journal of Nuclear Medicine May-August 2020• www.nuclmed.grFigure 3. In h stopatholog cal exam nat on, neoplast c prol ferat on formed by wavy elonge sp ndle cells, where the areas of Anton A and Anton B were located on the ground show ng xanthomatous and myxo d changes, were observed (A,B). In the mmunoh stochem cal exam nat on, S 100 d uz (+) (C); Act n, Desm n and CD34 are negat ve. The K -67 prol ferat on ndex was 5%. Atyp a and necros s have not been observed. The nal d agnos s was reported as schwannoma.
Schwannomas are the second most common ben gn per pheral nerve sheath or g nated tumor. Due to ts development from Schwann cells, t can be seen n all organs or t ssues dur ng ntracran al, extracran al, or sp nal nerve courses where these cells are found [1]. Schwannomas are extremely rare n the lung, regardless of the pat ent's age. Ohtsuka et al. (2005) [2] stated that n the rev ew of 62 pat ents w th ntrapulmonary or bronch al schwannoma (5-83 years; 28 male, 34 female pat ents), th s neoplasm const tutes approx mately 0.2% of all pulmonary neoplasms. Although t s usually sporad c and s ngle les on, t can also be seen w th neuro bromatos s NF1 or NF2 [3, 4]. Espec ally n schwannomatos s cases, NF2 s observed w th mult ple and ben gn cha-racters [5]. In pat ents w th tumors located prox mal to the lobar bronchus, atelectas s or pneumon a assoc ated w th cough and dyspnea may occur. However, most pat ents w th per pheral ntrapulmonary schwannoma have no symptoms [2]. Fluor ne-18 FDG-PET/CT s a useful mag ng modal ty to separate mal gnant sol tary pulmonary nodules from ben gn nodules. There are few
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cases of F-FDG PET/CT mag ng ntrapulmonary schwannoma n the l terature [6-9]. Max mum standardized uptake values 18
(SUVmax) of Schwannomas n F-FDG PET/CT are var able. Maximum standardized uptake values are generally low and mode-rate, but have been shown to vary between 1.9-7.2. The reason for the var at on n SUVmax s thought to be due to vary ng deg-rees of cellular ty, m crovascular dens ty or vascular permeab l ty [9]. H stopatholog cally, dense cellular areas (Antony A) and more hypocellular areas (Antony B) spec c to Schwannoma appear n vary ng proport ons. Also, the structure formed by sp n-dle schwann cells s de-by-s de w th n the elds of Antony (Verocay body) s character st c [10]. Surg cal resect on, endoscop c re-sect on and yttr um alum num garnet (YAG) laser rere-sect on were used for the treatment of pr mary ntrapulmonary schwan-noma [2].
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The contr but on of F-FDG PET/CT n schwannoma s that t prov des mal gn and ben gn d st nct ons of ntrapulmonary masses. However, a cuto for SUVmax has not been dent ed n the mal gnant ben gn d st nct on. The d agnos s must be ver
-ed h stopatholog cally.
Bibliography
1. Skovronsky DM, Oberholtzer JC. Patholog c class cat on of per pheral nerve tumors. Neurosurg Cl n N Am 2004; 15: 157-66. 2. Ohtsuka T, Nomor H, Naruke T et al. Intrapulmonary schwannoma. Jpn J Thorac Card ovasc Surg 2005; 53: 154-6.
3. Hall day AL, Sobel RA, Martuza RL. Ben gn sp nal nerve sheath tumors: the r occurrence sporad cally and n neuro bromatos s types 1 and 2. J Neurosurg 1991; 74: 248-53.
4. Ferner RE, O'Doherty MJ. Neuro broma and schwannoma. Curr Op n Neurol 2002; 15: 679-84.
5. Evans DG, Huson SM, Donna D et al. A cl n cal study of type 2 neuro bromatos s. Q J Med 1992; 84: 603-18.
6. Yabuk H, Tabata T, Sugawara T et al. Schwannoma occurred n the r ght upper bronch al nlet; report of a case. Kyobu Geka 2012; 65: 594-7. 7. Gonzalez M, Pr or JO, Rotman S et al. Ben gn ntrapulmonary schwannoma: aspect on F-18 uorodeoxyglucose PET/CT. Cl n Nucl Med 2011; 36: 465-7. 8. Nakamura R, Ish kawa S, Saka M et al. Increased uorodeoxyglucose-uptake n pos tron em ss on tomography w th an endobronch al schwannoma
occlud ng the left ma n stem bronchus. J Thorac Oncol 2009; 4: 1183-4.
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9. Ush yama T, Katsuda E, Tanaka M et al. F- uorodeoxyglucose uptake and apparent d us on coe c ent n lung schwannoma. Cl n Imag ng 2012; 36: 65-7.
10. Art co M, Cervon L, W erzb ck V et al. Ben gn neural sheath tumours of major nerves: character st cs n 119 surg cal cases. Acta Neuroch r(W en) 1997; 139: 1108-16.
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Az z Gültek n MD, Üm t Aydo mu MD, Hat ce Ar fo lu MD, Ferda B r MD, Olga Yaylal MD
1. Pamukkale Un vers ty, Med c ne Faculty, Department of Nuclear Med c ne, Den zl , Turkey. 2. Pamukkale Un vers ty, Med c ne Faculty,
Depart-9
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www.nuclmed.gr
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ment of Thorac c Surgery, Den zl , Turkey. 3. Pamukkale Un vers ty, Med c ne Faculty, Department of Pathology, Den zl , Turkey.
Corresponding author: Az z Gültek n, Ass st Prof Dr., Department of Nuclear Med c ne,Faculty of Med c ne, Pamukkale Un vers ty, Den zl ,
Turkey. E-ma l: agultek n@pau.edu.tr. Phone: +90 258 296 5307, Cell phone: +90 505 496 9348
