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 Table of Contents  
Year : 2019  |  Volume : 8  |  Issue : 1  |  Page : 24-26

Leiomyoma of the sigmoid mesocolon associated to hemorrhagic infarct and high count of mast cells

1 Department of Pathology, Carlos Van Buren Hospital; Department of Molecular Cell Biology, Universidad de Vaparaíso, Valparaíso, Chile
2 Department of Gastroenterology, Carlos Van Buren Hospital, Valparaíso, Chile
3 Department of Molecular Cell Biology; CResearch Center of Dental and Medical Sciences (CICOM),Universidad de Vaparaíso, Valparaíso, Chile

Date of Web Publication12-Mar-2019

Correspondence Address:
Dr. Carlo Lozano-Burgos
Department of Pathology, Carlos Van Buren Hospital, San Ignacio 725, Valparaíso
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/WJCS.WJCS_8_18

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Leiomyoma is a soft-tissue benign tumor and its occurrence in the mesocolon is extremely rare. We present a particular case of a leiomyoma of the sigmoid mesocolon of a 58-year-old man, associated to a hemorrhagic infarction treated surgically and without recurrences after 1 year of follow-up. The macroscopic, histopathologic, and immunohistochemical features are presented and discussed. The high mast cell count associated with a low rate of cell proliferation is a sign of the benign biological behavior in this entity and may be helpful hallmarks for the differential diagnosis with other gastroenterological neoplasia.

Keywords: Gastroenterology, immunohistochemistry, leiomyoma, macroscopy, mast cells, mesocolon

How to cite this article:
Lozano-Burgos C, Etcheverry-Pizarro C, González-Arriagada WA, Ochova-Gallardo P. Leiomyoma of the sigmoid mesocolon associated to hemorrhagic infarct and high count of mast cells. World J Colorectal Surg 2019;8:24-6

How to cite this URL:
Lozano-Burgos C, Etcheverry-Pizarro C, González-Arriagada WA, Ochova-Gallardo P. Leiomyoma of the sigmoid mesocolon associated to hemorrhagic infarct and high count of mast cells. World J Colorectal Surg [serial online] 2019 [cited 2021 Oct 27];8:24-6. Available from: https://www.wjcs.us.com/text.asp?2019/8/1/24/254039

  Introduction Top

Tumors of the mesocolon are infrequent, usually of mesenchymal origin, and in particular, those originating in the smooth muscle may have malignant biological behaviors even with an apparently benign morphology.[1],[2],[3],[4],[5] We present the infrequent case of a leiomyoma of the sigmoid mesocolon associated to a hemorrhagic infarction and megacolon, in a patient without previous diseases or recurrence after 1 year of surgery.

  Case Report Top

A 58-year-old man with a history of controlled arterial hypertension went to the gastroenterology department with the complaint of 1 week with abdominal pain and diarrhea. In the surgical emergency room, the patient had signs of intestinal obstruction, and computed tomography (CT) scan reports a probably obstructive tumor of the sigmoid colon, locally advanced.

In the surgery, a Hartmann operation was performed in a sigmoid megacolon with signs of ischemia and tumoral mass in the inferior mesenteric chain. In the anatomopathological examination [Figure 1], the surgical specimen corresponded to a segment of colon (36 cm.) dilated in one border (megacolon) with signs of transmural hemorrhagic infarction and with a tumor mass in the sigmoid mesocolon of 5.5 cm × 3.6 cm. This tumor had a smooth surface, multinodular appearance and to the cut surface was whitish and homogenous. In the histological study with conventional stain [Figure 2], the tumor was composed by a proliferation of fusiform cells with a bland appearance, compatible with fascicles of smooth musculature. The histological features observed were totally benign, without mitosis, atypia, or necrosis.
Figure 1: Surgical specimen corresponding to sigmoid megacolon (comparison of diameters in red line) with a hemorrhagic infarction (right). In the mesocolon, a lobulated tumor mass, homogeneous, and whitish

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Figure 2: Microscopic image of the neoplasia, composed of cross-linked bands of smooth muscle cells without mitosis, atypia, or necrosis (H and E, ×400)

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The immunohistochemical study determined that the cells were positive for smooth muscle actin and negative for CD117, with a Ki-67 proliferation index of 2% [Figure 3]. The association of the clinical, imagenological, macroscopic, histological, and immunohistochemical observations leads to the diagnosis of a leiomyoma of the sigmoid mesocolon.
Figure 3: Immunohistochemistry. (a) Smooth muscle actin, showing strong positivity in the cytoplasm of neoplastic cells (b), Positive control in the wall of the cecal appendix. (c), Nuclear expression of ki-67, showing a low rate of cell proliferation (2%). (d), Positive control in the germinal centre of a lymph node. (e), Negativity for CD117 in neoplastic cells and positivity in the cytoplasm of mast cells. (f), Positive control in testicular seminoma. (g), Giemsa stain for mast cells in the neoplasia

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In addition, the tumor showed numerous mast cells, demonstrated by the correlation of Giemsa histochemical staining and immunohistochemistry for CD117, homogeneously distributed, with an average count of 21.8 per high-power field (value measured in 10 high-power field). The patient evolves without surgical complications or residual disease in the CT scan control, 1 year later.

  Discussion Top

The main difficulty in the assessment of mesenteric smooth muscle tumors is that the biological behavior cannot be predicted with those morphological parameters classically described in uterine location such as mitosis, atypia, and necrosis.[3],[4],[5],[6],[7],[8],[9] It has been reported that the tumor size constitutes a significant risk factor in the biological behavior of the tumor.[5] In the current case, it is probably that the hemorrhagic infarct of the colon and the megacolon would have been caused by the tumor, considering its location in the surgical specimen.

In general, mast cell count has increased in some smooth muscle cell neoplasms, such as the cellular leiomyoma of the uterus, and it is an element that can be used in differential diagnosis with malignant neoplasms such as leiomyosarcoma,[3],[6] due to the predominance of these cells in benign tumors.[10],[11] In the case presented here, there is a high mast cell count which could be used as a criterion of benign biological behavior in mesenteric smooth muscle tumors. It is described that the increased number of mast cells is associated with the expression of chemokines (CCL5 and CCL11 ) in the tumor cells[12] and should be considered because it can cause an mistake in the differential diagnosis with a gastrointestinal stromal tumor (GIST),[13] if no histochemical staining is done to study the population of mast cells (Giemsa or toluidine blue).

The main differential diagnosis in this location corresponds to the GIST, characterized by the immunohistochemical expression of CD117/c-kit in the cytoplasmic membrane of the neoplastic cells. Other tumors that should also be considered as differential diagnosis are well-differentiated liposarcoma, malignant fibrous histiocytoma, inflammatory myofibroblastic tumor, and peripheral nerve sheath tumor.[5] It is necessary, in the case of women, the evaluation of a parasitic leiomyoma or a benign metastasizing leiomyoma, when there is coexistence with one or more leiomyomas of the uterus.[7]

  Conclusion Top

We conclude that this is an unusual case of a leiomyoma of the sigmoid mesocolon associated with a hemorrhagic infarction and megacolon, without recurrence after 1 year of surgery. The high mast cell count and a low proliferation index by immunohistochemistry for Ki-67 are useful information for the differential diagnosis. It can be used as a pathological criterion to predict a nonaggressive biological behavior, in smooth muscle tumors of the mesocolon.

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.


We would like to thank Rodrigo Zúñiga, medical technologist, for his support in the laboratory.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Balaji R, Ramachandran K, Somanathan T. A rare case of solitary fibrous tumour of the sigmoid mesocolon: Imaging features and review of literature. Cancer Imaging 2009;9:67-9.  Back to cited text no. 1
Demir R, Schmid A, Hohenberger W, Agaimy A. Angiolipomatous mesenchymal hamartoma (angiolipomatosis) of the sigmoid mesocolon. Int J Clin Exp Pathol 2011;4:210-4.  Back to cited text no. 2
Jai SR, Farah RH, Hamdaoui B, Boufettal R, Chehab F. Pleomorphous leiomyosarcoma of the mesocolon: A case report. Pan Afr Med J 2015;22:322.  Back to cited text no. 3
Marullo U, D Amico G. Rare case of leiomyoma of the descending mesocolon. G Ital Chir 1964;20:127-40.  Back to cited text no. 4
Kalogiannidis I, Stavrakis T, Amplianitis I, Grammenou S, Mavromatidis G, Rousso D, et al. Primary mesenteric smooth muscle tumor: An entity with unpredictable biologic behavior. Case Rep Obstet Gynecol 2013;2013:483689.  Back to cited text no. 5
Agarwal K, Nangia A, Bajaj P, Niveditha SR. Leiomyosarcoma of the mesocolon – A case report. Indian J Pathol Microbiol 2000;43:467-9.  Back to cited text no. 6
[PUBMED]  [Full text]  
Fasih N, Prasad Shanbhogue AK, Macdonald DB, Fraser-Hill MA, Papadatos D, Kielar AZ, et al. Leiomyomas beyond the uterus: Unusual locations, rare manifestations. Radiographics 2008;28:1931-48.  Back to cited text no. 7
Shraibman S, French RJ. Giant leiomyosarcoma of the transverse mesocolon. Aust N Z J Surg 1999;69:749-51.  Back to cited text no. 8
Tonouchi S, Yoshida S, Ichikawa S. Case of giant leiomyoma of the mesenterium of the transverse colon. Geka Chiryo 1968;19:230-4.  Back to cited text no. 9
Lü JQ, Zhu XQ, Dong K, Xiang M, Lin Y, Hu Y, et al. Study of the mechanism of mast cell increase in cellular leiomyoma of uterus. Zhonghua Fu Chan Ke Za Zhi 2007;42:390-3.  Back to cited text no. 10
Orii A, Mori A, Zhai YL, Toki T, Nikaido T, Fujii S, et al. Mast cells in smooth muscle tumors of the uterus. Int J Gynecol Pathol 1998;17:336-42.  Back to cited text no. 11
Zhu XQ, Lv JQ, Lin Y, Xiang M, Gao BH, Shi YF, et al. Expression of chemokines CCL5 and CCL11 by smooth muscle tumor cells of the uterus and its possible role in the recruitment of mast cells. Gynecol Oncol 2007;105:650-6.  Back to cited text no. 12
Wong NA, Pawade J. Mast cell-rich leiomyomas should not be mistaken for gastrointestinal stromal tumours. Histopathology 2007;51:273-5.  Back to cited text no. 13


  [Figure 1], [Figure 2], [Figure 3]


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