Endoscopic ultrasound-guided fine-needle aspiration cytology in the diagnosis of leiomyomas of the gastrointestinal tract

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Endoscopic ultrasound-guided fine-needle aspiration cytology in the diagnosis of leiomyomas of the gastrointestinal tract José-Fernando Val-Bernal a,∗ , María Martino b , Alvaro Terán c , Elena Yllera d , Beatriz Castro-Senosiain c a

Pathology Unit, Medical and Surgical Sciences Department, University of Cantabria and IDIVAL Research Institute, Santander, Spain b Anatomical Pathology Service, Marqués de Valdecilla University Hospital, University of Cantabria and IDIVAL Research Institute, Santander, Spain c Digestive Service, Marqués de Valdecilla University Hospital, Santander, Spain d Radiodiagnostic Service, Marqués de Valdecilla University Hospital, Santander, Spain Received 21 July 2018; accepted 18 September 2018

KEYWORDS Gastrointesinal tract; Gastrointestinal stromal tumor; Leiomyoma; Leiomyosarcoma; Endoscopic ultrasound

∗

Abstract We investigated the efficiency and accuracy of endoscopic ultrasound-guided fineneedle aspiration cytology (EUS-FNAC) in the diagnosis of gastrointestinal leiomyoma (GIL). Between January 2009 and May 2018 we performed 795 EUS-FNAC studies of lesions of the gastrointestinal (GI) tract for various clinical indications. A diagnosis of GIL by cytological and cell block study was made in 14 patients (57.1% males, mean age 53.6 years, range 22---84 years). 7 tumors (50%) were detected incidentally. The lesions ranged in size from 2 to 10 cm (mean size 4.4 cm). The location of the tumors was: esophagus 7 (50%), stomach 6 (42.9%) and rectum 1(7.1%). The mean size of the symptomatic tumors was 5.2 cm (range 3---10 cm). The follow-up of the 14 patients varied from 1 to 108 months (median 39.5 months), during which no recurrence or evidence of lesion progression was observed. Imaging alone was not sufficient for an accurate diagnosis to be made. The pathological diagnosis was based on a combination of cytological, histopathological, and immunohistochemical features. The intracytoplasmic eosinophilic globule is a useful marker of paucicellular GIL differentiating it from gastrointestinal stromal tumor and leiomyosarcoma. EUS-FNAC is a reliable, accurate, and safe method for the diagnosis of GIL. © 2018 Sociedad Espa˜ nola de Anatom´ıa Patol´ ogica. Published by Elsevier Espa˜ na, S.L.U. All rights reserved.

Corresponding author. E-mail address: [email protected] (J.-F. Val-Bernal).

https://doi.org/10.1016/j.patol.2018.09.003 1699-8855/© 2018 Sociedad Espa˜ nola de Anatom´ıa Patol´ ogica. Published by Elsevier Espa˜ na, S.L.U. All rights reserved.

Please cite this article in press as: Val-Bernal J-F, et al. Endoscopic ultrasound-guided fine-needle aspiration cytology in the diagnosis of leiomyomas of the gastrointestinal tract. Rev Esp Patol. 2018. https://doi.org/10.1016/j.patol.2018.09.003

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PALABRAS CLAVE Tracto digestivo; Tumor del estroma gastrointestinal; Leiomioma; Leiomiosarcoma; Ecografía endoscópica

Citología por aspiración con aguja fina guiada por ecografía endoscópica en el diagnóstico de los leiomiomas del tracto digestivo Resumen Hemos investigado la eficacia y la precisión de la citología por aspiración con aguja fina guiada por ecografía endoscópica (EUS-FNAC) en el diagnóstico del leiomioma gastrointestinal (LGI). Entre enero de 2009 y mayo de 2018 se realizaron 795 estudios EUS-FNAC de lesiones del tracto digestivo por una variedad de indicaciones clínicas. Catorce pacientes (57,1% varones, edad media: 53,6 a˜ nos, rango: 22-84 a˜ nos) fueron diagnosticados mediante estudio citológico y de bloque celular de LGI. Siete tumores (50%) fueron detectados de manera incidental. Las lesiones variaron en tama˜ no de 2 a 10 cm (tama˜ no promedio: 4,4 cm). La localización de los no medio de los tumores fue: esófago 7 (50%), estómago 6 (42,9%) y recto uno (7,1%). El tama˜ tumores sintomáticos fue de 5,2 cm (rango: 3-10 cm). El seguimiento de los 14 pacientes varió de uno a 108 meses (mediana: 39,5 meses). No se observó recurrencia o evidencia de progresión de la lesión. El estudio de las imágenes radiológicas por sí solo no permitió diagnosticar la lesión. El diagnóstico patológico se basó en una combinación de datos citológicos, histopatológicos e inmunohistoquímicos. El glóbulo eosinofílico intracitoplasmático es un marcador útil de LGI paucicelular que permite diferenciarlo del tumor del estroma gastrointestinal y del leiomiosarcoma. La EUS-FNAC es un método fiable, preciso y seguro para el diagnóstico del LGI. © 2018 Sociedad Espa˜ nola de Anatom´ıa Patol´ ogica. Publicado por Elsevier Espa˜ na, S.L.U. Todos los derechos reservados.

Introduction Gastrointestinal mesenchymal tumors form a heterogeneous group that includes several distinct entities with different clinico-pathologic profiles, principally leiomyomas, schwannomas, lipomas, hemangiomas, gastrointestinal stromal tumors (GISTs) and non-GIST sarcomas. Although leiomyomas are uncommon throughout the digestive system, they are the most common mesenchymal tumors of the esophagus1 ; indeed, the esophagus is the only site in the gastrointestinal (GI)tract where leiomyomas predominate. GISTs far outnumber leiomyomas in the stomach, small bowel and colon and are by far the most frequent mesenchymal tumor of the digestive system, as they account for approximately 90% of all mesenchymal tumors of the GI tract.2 It is of great importance for clinicians and pathologists to distinguish leiomyoma from GIST as leiomyoma is benign and GIST is associated with a variable risk of progression and metastasis; furthermore, it requires different therapeutic regimes. The combination: endoscopic ultrasound-guided (EUS) fine-needle aspiration cytology (FNAC) appears to be of great value in the evaluation of intramural lesions of the gastrointestinal tract. However, there is only limited experience of its use in the diagnosis of gastrointestinal leiomyoma.3,4 In this study, we investigated the efficiency and accuracy of EUS-FNAC in the diagnosis of digestive tract leiomyoma in a series of 14 cases.

Materials and methods Between January 2009 and May 2018, we performed 795 EUS-FNAC studies of GI tract lesions. All the cases were

seen in-house. Gastrointestinal leiomyoma was diagnosed in 14 patients by cytopathological examination. Clinical and pathological reports were reviewed. Patients were prepared for EUS-FNAC procedure by using conscious sedation with propofol and fentanyl. The procedure was performed on an outpatient basis. We used an echoendoscope EG 3630UR, Pentax (SIMMEDICA, Madrid Spain). The echoendoscope was connected to a monitoring device EUB-7500A, Hitachi (Hitachi Medical Systems SLU, Madrid, Spain), and the EUS-FNAC was performed using 22-gauge needles. All patients underwent endoscopic ultrasound; in 11 cases a computed tomography (CT) scan was carried out to evaluate diverse abdominal symptoms. One magnetic resonance image (MRI) was available for review. A rapid on-site evaluation of the aspirate was performed in all cases for specimen adequacy. The aspirate smears were stained with Diff-Quik and Papanicolaou method. Slides were reviewed for cellularity, density of nuclei, amount of cytoplasmic volume, cellular and nuclear shape, presence of nucleoli, and cohesiveness of tissue fragments in the smears. In 13 cases we had cell block preparations. Cell block material was fixed in 10% formalin and embedded in paraffin. Thin (4␮m-thick) sections were stained with hematoxylin and eosin and periodic acid Schiff (PAS) procedure. Immunopathological study was carried out on cytoblock sections, using the EnVision FLEX Visualization System (Dako, Agilent Technologies, SL, Las Rozas, Madrid, Spain). Antibodies used in the immunohistochemical study are detailed in Table 1. Immunohistochemical reactions were performed using appropriate tissue controls. Automatic staining was accomplished on a Dako Omnis autostainer (Agilent Technologies, SL). Due to the limited material in the cytoblocks, not all tumors were stained with the same series of antibodies. Sufficient material for diagnosis was obtained in all cases.

Please cite this article in press as: Val-Bernal J-F, et al. Endoscopic ultrasound-guided fine-needle aspiration cytology in the diagnosis of leiomyomas of the gastrointestinal tract. Rev Esp Patol. 2018. https://doi.org/10.1016/j.patol.2018.09.003

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EUS-FNAC in gastrointestinal leiomyomas Table 1

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Antibodies used in this study.

Antibody

Source

Clone

Dilution

Retrieval solution pH (Dako)

Smooth-muscle actin Desmin Human-muscle actin h-Caldesmon CD34 CD117 DOG-1 S100 protein Ki-67

Dako Dako Dako Dako Dako Dako Novocastra Dako Dako

1A4 D33 HHF35 h-CD QBEnd 10 Polyclonal K9 Polyclonal MIB-1

FLEX RTU FLEX RTU FLEX RTU FLEX RTU FLEX RTU 1/200 1/100 FLEX RTU FLEX RTU

High High High High High High High High Low

Dako, Agilent Technologies SL, Madrid, Spain; Novocastra, Leica Biosystems, Wetzlar, Germany.

We considered as incidental findings those cases where symptoms were not attributable to the tumor; the asymptomatic lesions had been discovered in an imaging study prior to the practice of EUS-FNAC.

Results Over the study period (9 years and 4 months) we analyzed the data from 14 patients who underwent EUS-FNAC (Table 2). The patients ranged in age from 22 to 84 years (mean 53.6 years). 8 (57.1%) patients were male and 6 were female. 7 (50%) tumors were detected incidentally. The lesions ranged in size from 2 to 10 cm (mean size 4.4 cm). The location of the tumors was the following: esophagus 7 (50%), stomach 6 (42.9%), and rectum 1(7.1%). The mean size of the incidental tumors was 3.7 cm (range 1.6---7.0 cm). The mean size of the symptomatic tumors was 5.2 cm (range 3---10 cm). The follow-up of the 14 patients varied from 1 to 108 months (median 39.5 months), during which no recurrence or evidence of lesion progression was observed. EUS findings in all cases were characterized by low echogenicity similar to that of proper muscle layer. Lesions showed round to oval shapes and regular borders (Fig. 1). CT unenhanced scans revealed round to ovoid, smoothly marginated masses of muscle attenuation, lying intramurally in the GI tract (Fig. 2A). Enhanced scans showed that tumor attenuation was homogeneously isointense, or slightly lower, compared to chest or abdominal wall muscle. Calcification, central necrosis, or peritumoral invasion was not seen. In one patient (case 10), unenhanced T1-weighed axial MR images showed slight hyperintensity, while enhanced T1-weighted MR images demonstrated slight homogeneous enhancement. On T2-weighed MR images, the lesion was slightly hyperintense (Fig. 2B). The smears of all 14 cases showed a hemorrhagic background with a few dissociated single cells. The nuclei appeared stripped and ranged in shape from oval to markedly elongated, showing fine chromatin and faint nucleoli. These rod-like nuclei sometimes displayed light waviness (Fig. 3A). In addition, in 11 (78.6%) cases the smears contained a variable number of microfragments with tightly clustered tumor cells (Fig. 3B). The cells were of uniform size and had thin, rod-shaped nuclei in parallel alignment

with scant nuclear overlap. These nuclei were embedded in a fibrillary cytoplasmic syncytium. The cells were uniformly distributed and lacked significant atypia (Fig. 3C). No mitoses were observed. In addition, depending on the location, squamous or columnar cells of the mucosal covering were seen. Microscopically, the sections of the cytoblocks showed mature-appearing spindle cells arranged in intersecting fascicles and whorls. Cells had eosinophilic cytoplasm and unremarkable, uniformly blunt-ended, cigar-shaped nuclei. Cellularity was variable. Most lesions were paucicellular (11/13, 84.6%) showing large amounts of cytoplasm (Fig. 4A). In other cases, the cellularity was moderate (2/13, 15.4%), with smaller, closely packed cells (Fig. 4B). No multinucleated tumor cells, nuclear atypia, mitotic activity or necrosis were seen. Occasionally, deposition of dense hyalinized collagen was observed. A significant finding was the presence of intracytoplasmic eosinophilic (hyaline) globules (IEGs) in 38.5% (5/13) of cases. IEGs were only observed in paucicellular tumors. These IEGs stood out when the refringence was increased by pulling down the auxiliary lens of the condenser. They had an irregular distribution and were abundant in some areas. These intracytoplasmic inclusions resulted in rhabdoid (Fig. 5A) or skeletal muscle-like features (Fig. 5B). IEGs were not observed in the smears. Tumor cells showed reactivity for smooth-muscle actin (13/13, 100%, Fig. 6A), desmin (13/13, 100%, Fig. 6B), human-muscle actin (HHF35, 7/7, 100%, Fig. 6C), and h-caldesmon (7/7,100%, Fig. 6D). All 13 cases showed positivity for at least two immunohistochemical muscle cell markers. CD34 (0/13, 0%), CD117 (c-kit, 0/13, 0%), DOG-1 (0/7, 0%) and S100 protein (0/13, 0%) stains were negative in all cases. Ki-67 labeling index revealed a low growth tumor fraction in the 6 cases in which it was carried out. The IEGs were PAS negative, and reactive for smooth-muscle actin, desmin, human-muscle actin, and h-caldesmon. The case without cell block (case 1) showed tissue microfragments in the smears that were typical of paucicellular leiomyoma. No clinical complications arose from the use of the EUSFNAC technique. 8 (57.1%) patients underwent surgical excision of the tumors (cases 1, 4---8, 10, and 11) and histopathology confirmed the diagnosis of leiomyoma in all of them; cases 7 and 10 were of moderate cellularity type. Due to the

Please cite this article in press as: Val-Bernal J-F, et al. Endoscopic ultrasound-guided fine-needle aspiration cytology in the diagnosis of leiomyomas of the gastrointestinal tract. Rev Esp Patol. 2018. https://doi.org/10.1016/j.patol.2018.09.003

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Clinical details of patients with leiomyomas of the digestive system. Age(y)/Sex

Presentation

Main ailment

Location

Size (cm)

Follow-up (months)/outcome

1

22/M

Dysphagia

Esophagus (middle third)

10.0

108/NEP

2

58/M

Incidental

Esophagus (lower third)

4.2

99/NEP

3 4 5 6 7

38/M 54/F 59/F 51/M 61/M

Incidental Incidental Dyspepsia Incidental Melenas

Stomach (antrum) Stomach (fundus) Stomach (cardia) Esophagus (lower third) Stomach (cardia)

2.3 5.0 3.4 7.0 4.2

62/NEP 58/NEP 49/NEP 46/NEP 44/NEP

8

61/F

Stomach (antrum)

3.0

35/NEP

9 10 11 12 13

84/F 54/M 26/M 62/M 49/F

High digestive hemorrhage Melena Incidental Constipation Gastroesophageal reflux Incidental Dyspepsia

Dysphagia Occasional vomiting Peptic ulcer Hepatic cirrhosis Chronic diarrhea Sigmoid diverticulitis Dyspepsia Acute cholecystitis Deficit of vitamin B12 and folic acid Colon adenomas Peptic ulcer Colon carcinoma Acquired immunodeficiency syndrome Gastroesophageal reflux Hypopharyngeal carcinoma Dyspepsia

Stomach (cardia) Rectum Esophagus (lower third) Esophagus (middle third) Esophagus (lower third)

3.5 7.5 3.9 2.0 4.6

33/NEP 24/NEP 10/NEP 8/NEP 1/NEP

14

72/F

Incidental

Chronic bronchitis Paraseptal and centrilobular emphysema Bronchiectasis

Esophagus (middle third)

1.6

2/NEP

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Case no.

NEP, no evidence of progression.

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Please cite this article in press as: Val-Bernal J-F, et al. Endoscopic ultrasound-guided fine-needle aspiration cytology in the diagnosis of leiomyomas of the gastrointestinal tract. Rev Esp Patol. 2018. https://doi.org/10.1016/j.patol.2018.09.003

Table 2

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EUS-FNAC in gastrointestinal leiomyomas

Figure 1 Endoscopic ultrasound revealing a 16 × 11 mm, anechoic, ovoid, well-delimited lesion originating from the muscular layer of the middle third of the esophagus (case 14).

stability of the lesions and the clinical condition of the 6 remaining patients, a biannual control was carried out.

Discussion Mesenchymal tumors of the GI tract are uncommon, accounting for only a small percentage of all gastrointestinal neoplasms.1 Clinically, significant gastrointestinal leiomyoma mainly occurs in the esophagus and stomach. The incidence in the small and large intestine is markedly lower. In an ultrasonography endoscopic study of 106 patients, the frequency of cases of this tumor was: esophagus 66 (62.3%), stomach 35 (33%), duodenum 2 (1.9%), and colon 3 (2.8%).5 Furthermore, rectal leiomyoma is considered a rare entity.6 This is consistent with our data, as we found that leiomyomas were more frequent within theesophagus. Gastrointestinal leiomyomas may cause obstructive symptoms and/or bleeding due to ulceration, or are discovered during endoscopy for unrelated symptoms. 50% of

5 our cases were detected in this way. Yang et al. observed 7 (58.3%) incidental cases in a series of 12 esophageal leiomyoma.7 Mean tumor size among symptomatic patients was 5.2 cm. This figure is similar to that reported by Jiang et al.8 A rare case presenting as gastric volvulus has been reported.9 Due to their intramural location, leiomyomas can be difficult to biopsy by traditional methods. EUS combines the function of endoscope and ultrasound, allowing both an inspection of the surface and a complete image of the GI tract and thus the size, margins, and echotexture can all be assessed. With this procedure, gastrointestinal leiomyoma usually appears as a homogeneous and hypoechoic lesion with clear margins.5 EUS features, such as inhomogeneity, hyperechogenic spots, a marginal halo, and higher echogenicity than the surrounding muscle layer, may help to differentiate GISTs from leiomyomas.10 However, the EUS image alone lacks specificity.11 As EUS-FNAC enables sampling of intramural lesions, it can be used to diagnose these tumors. Homogeneous tumor attenuation and poor enhancement pattern on CT scan are the most significant features of gastrointestinal leiomyoma. Low to intermediate enhancement degree of leiomyomas can be due to their low to moderate cellularity and vascularity.7,12 Conversely, GIST shows areas of hemorrhage, necrosis or cystic degeneration that result in heterogeneous enhancement and intratumoral low attenuation.7 Although CT scans may recognize these lesions, they are unable to reveal their precise nature.5,13 MRI of gastrointestinal leiomyoma shows a wellcircumscribed mass of low signal intensity or isointense compared with normal muscularis propria on T1-weighted images, and low signal intensity on T2-weighted images. Thus, in order to establish an exact diagnosis, the lesion must be sampled. Imaging alone is not sufficient for an accurate diagnosis of the tumor’s subcategory. Cytologically, the density of nuclei and cohesivity of tumor microfragments in the smears are the most important criteria in the distinction between leiomyoma and GIST

Figure 2 Computed tomography (CT) and magnetic resonance imaging (MRI). (A) In the lesser gastric curvature a hypodense, rounded, well-defined intramural mass of 5 cm in diameter is observed (CT axial image, case 4). (B) In the rectal wall there is a well-defined, solid mass homogenously hypointense in T1 and T2. After administration of intravenous contrast, it has a homogenous character. The mass compresses the postero-inferior aspect of the bladder and prostate (MRI, case 10).

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Figure 3 Cytologic features. (A) Low cellularity smear showing dissociated single cells with stripped cigar-shaped or ovoid nuclei (case 2, Diff-Quik stain, 400×). (B) Tightly aggregated microfragment of tumor cells embedded in a syncytium and in parallel arrangement (case 13, Papanicolaou stain, 200×). (C) Nuclei are uniformly sized and rod-shaped. Cells are somewhat spaced and lack significant atypia (case 13, Papanicolau stain, 400×).

Figure 4 Histopathology of leiomyoma of the GI tract. (A) Paucicellular type (case 6, H/E stain, 200×). (B) Moderately cellular type (case 10, H/E stain, 200×).

or leiomyosarcoma. GISTs show higher overall cellularity, with spindle, epithelioid, or, rarely, pleomorphic cells with a basophilic appearance. Leiomyosarcomas display high cellularity, numerous mitotic figures and necrosis. Histopathological assessment of low or moderate cellularity, eosinophilic cytoplasm, few or absent mitoses, and lack of nuclear pleomorphism and necrosis suggest leiomyoma. However, an immunohistochemical study of the cell block is essential. Almost 100% of the GISTs will show positivity for CD117 or DOG-1 and up to 80% will be reactive for CD34.1,14 DOG-1 is the most sensitive and specific of the three markers.15 GISTs may display reactivity for smooth muscle actin but is focal. Conversely, leiomyomas

are diffusely reactive for smooth-muscle actin, desmin, and human-muscle actin and show negativity for CD117, DOG-1, CD34, and S100 protein. Leiomyosarcomas display high cellularity, numerous mitotic figures, high growth tumor fraction, by the Ki67 labeling index, and necrosis. IEGs can be observed in leiomyomas of diverse locations, such as uterus,16,17 bladder,18 and GI tract.19---21 IEGs have been described in 2.7% of uterine leiomyomas.16 Recently, these structures have been considered a characteristic feature of fumarate hydratase deficiency in uterine leiomyomas.17 Gastrointestinal leiomyomas frequently contain IEGs; Matsukuma et al.20 observed IEGs in 60% of

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Figure 5 Intracytoplasmic eosinophilic (hyaline) globules. (A) Multiple eosinophilic globules. Some cells have a rhabdoid appearance (case 9, H/E stain, 400×). (B) In some cells, there is skeletal muscle-like appearance (case 4, H/E stain, 400×).

Figure 6 Immunohistochemistry. Tumor cell show reactivity for: (A) smooth muscle actin (case 13, 100×), (B) desmin (case 4, 200×), (C) human-muscle actin (case 7, 400×), and (D) h-caldesmon (case 7, 400×).

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colorectal leiomyomas whose size varied from 2 to 10 mm. Agaimy et al.21 reported these globular structures in 100% of paucicellular leiomyomas and their absence in cellular leiomyomas or leiomyosarcomas. On the other hand, IEGs show variable histochemical and immunohistochemical reactivity. They are considered to be degenerating smooth muscle cells,18 whose characteristic feature is a globular (hyaline) eosinophilic aspect with H&E staining. These intracellular globules must be differentiated from the extracellular, PAS-positive skeinoid fibers characteristic of GISTs and from the intra- and extra-cellular thanatosomes that are more prominent in aggressive neoplasms with a high cell turnover, or in treatment with chemotherapy or radiation.22 Therefore, IEG is a useful marker of paucicellular gastrointestinal leiomyoma that allows differentiation from GIST or leiomyosarcoma without using immunohistochemistry. Matsukuma et al.20 observed the constant absence of IEGs in the intestinal muscle layer. They suggested that this could be valuable in differentiating intramural leiomyoma from the reactive thickening of the muscular layer of the gastrointestinal tract in small biopsies. However, Agaimy et al.21 reported the occasional presence of IEGs in the normal muscular layer. Therefore, IEGs have only a limited value in this differential diagnosis. The absence of IEGs in the smears and their presence in a few cytoblock sections is attributable to their irregular distribution in the tumors. EUS-FNAC is a safe technique. Overall complication rates published range between 0.3% and 2.2%.11 Major complications include infections, intraluminal and extraluminal bleeding, and acute pancreatitis.13 In the present study, suitable cellular smears and cell blocks were obtained using the EUS-FNAC procedure and no complications were observed. In conclusion, EUS-FNAC is a reliable, accurate and safe method for the diagnosis of leiomyomas of the gastrointestinal tract. The pathological diagnosis is based on a combination of cytological, histopathological, and immunohistochemical characteristics. IEG is a useful marker of paucicellular gastrointestinal leiomyoma differentiating it from GIST and leiomyosarcoma.

Compliance with ethical standards This study was approved by the Ethics Committee of IDIVAL Research Institute (CI:2018.162) and confirmed to the provisions of the Declaration of Helsinki

Funding No external funding for this work.

Conflicts of interest None to declare.

References 1. Hamilton SR, Aaltonen LA. World Health Organization Classification of tumors. Pathology and genetics of tumors of the digestive system. Lyon: IARC Press; 2000. 2. Kang HC, Menias CO, Gaballah AH, Shroff S, Taggart MW, Garg N, et al. Beyond the GIST: mesenchymal tumors of the stomach. Radiographics. 2013;33:1673---90. 3. Stelow EB, Stanley MW, Mallery S, Lai R, Linzie BM, Bardales RH. Endoscopic ultrasound-guided fine-needle aspiration findings of gastrointestinal leiomyomas and gastrointestinal stromal tumors. Am J Clin Pathol. 2003;119:703---8. 4. Todaro P, Crino SF, Ieni A, Pallio S, Consolo P, Tuccari G. Intraparietal esophageal leiomyomas diagnosed by endoscopic ultrasound-guided fine-needle aspiration cytology: cytological and immunocytochemical features in two cases. Oncol Lett. 2014;8:123---6. 5. Xu G-Q, Zhang BL, Li YM, Chen LH, Ji F, Chen WX, et al. Diagnostic value of endoscopic ultrasonography for gastrointestinal leiomyoma. World J Gastroenterol. 2003;9: 2088---91. 6. Sunkara T, Then EO, Culliford A, Gaduputi V. Rectal leiomyoma, a rare entity. Clin Pract. 2018;8:1053. 7. Yang HK, Kim YH, Lee YJ, Park JH, Kim JY, Lee KH, et al. Leiomyomas of the gastric cardia: CT findings and differentiation from gastrointestinal stromal tumors. Eur J Radiol. 2015;84:1694---700. 8. Jiang W, Rice TW, Goldblum JR. Esophageal leiomyoma: experience from a single institution. Dis Esophagus. 2013;26: 167---74. 9. Deevaguntla CR, Prabhakar B, Prasad GR, Bhaskaran S, Venkateswarlu K. Gastric leiomyoma presenting as gastric volvulus. Indian J Gastroenterol. 2003;22:230---1. 10. Kim GH, Park DY, Kim S, Kim DH, Kim DH, Choi CW, et al. Is it possible to differentiate gastric GISTs from gastric leiomyomas by EUS? World J Gastroenterol. 2009;15: 3376---81. 11. Pavic T, Hrabar D, Duvnjak M. The role of endoscopic ultrasound in evaluation of gastric subepithelial lesions. Coll Antropol. 2010;34:757---62. 12. Lee MJ, Lim JS, Kwon JE, Kim H, Hyung WJ, Park MS, et al. Gastric true leiomyoma: computed tomographic findings and pathological correlation. J Comput Assist Tomogr. 2007;31:204---8. 13. Jenssen C, Dietrich CF. Endoscopic ultrasound-guided fineneedle aspiration biopsy and trucut biopsy in gastroenterology. An overview. Best Pract Res Clin Gastroenterol. 2009;23:743---59. 14. Lopes LF, West RB, Bacchi LM, van de Rijn M, Bacchi CE. DOG1 for the diagnosis of gastrointestinal stromal tumor (GIST): comparison between 2 different antibodies. Appl Immunohistochem Mol Morphol. 2010;18:333---7. 15. Fatima N, Cohen C, Siddiqui MT. DOG1 utility in diagnosing gastrointestinal stromal tumors on fine-needle aspiration. Cancer Cytopathol. 2011;119:202---8. 16. Dundr P, Pov´ ysil C, Tvrdík D, Mára M. Uterine leiomyomas with inclusion bodies: an immunohistochemical and ultrastructural analysis of 12 cases. Pathol Res Pract. 2007;203: 145---51. 17. Siegler L, Erber R, Burghaus S, Brodkorb T, Wachter D, Willkinson N, et al. Fumarate hydratase (FH) deficiency in uterine leiomyomas: recognition by histological features

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EUS-FNAC in gastrointestinal leiomyomas versus blind immunoscreening. Virchows Arch. 2018;472: 789---96. 18. Alroy J, Ucci AA, Tischler AS, Mitcheson HD. Intracytoplasmic inclusion bodies in leiomyoma of the urinary bladder. Ultrastruct Pathol. 1983;5:89---91. 19. Dundr P, Pov´ ysil C, Tvrdík D. Leiomyoma of the gastrointestinal tract with intracytoplasmic inclusion bodies. Report of three cases. Cesk Patol. 2006;42:139---44. 20. Matsukuma S, Takeo H, Ohara I, Sakai Y. Endoscopically resected colorectal leiomyomas often containing eosinophilic globules. Histopathology. 2004;45:302---3.

9 21. Agaimy A, Wünsch PH, Hofstädter F, Schroeder J. Hyaline globules in paucicellular leiomyomas of the gastrointestinal tract are distinct from skeinoid fibers and represent degenerating smooth muscle cells. Pathol Res Pract. 2009;205: 417---22. 22. Papadimitriou JC, Drachenberg CB, Brenner DS, Newkirk C, Trump BF, Silverberg SG. Thanatosomes: a unifying morphogenetic concept for tumor hyaline globules related to apoptosis. Hum Pathol. 2000;31:1455---65.

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