|LETTER TO THE EDITOR
|Year : 2015 | Volume
| Issue : 4 | Page : 502-504
Microsatellite stable adenocarcinoma in a pediatric patient presenting as a dual mass in the colon and cecum: A rare presentation
SY Sunil, GU Rasika, DF Grace
Department of Pathology, S. R. T. R. Government Medical College, Ambajogai, District Beed, Maharashtra, India
|Date of Web Publication||10-Mar-2016|
S Y Sunil
Department of Pathology, S. R. T. R. Government Medical College, Ambajogai, District Beed, Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sunil S Y, Rasika G U, Grace D F. Microsatellite stable adenocarcinoma in a pediatric patient presenting as a dual mass in the colon and cecum: A rare presentation. Indian J Cancer 2015;52:502-4
|How to cite this URL:|
Sunil S Y, Rasika G U, Grace D F. Microsatellite stable adenocarcinoma in a pediatric patient presenting as a dual mass in the colon and cecum: A rare presentation. Indian J Cancer [serial online] 2015 [cited 2019 Dec 16];52:502-4. Available from: http://www.indianjcancer.com/text.asp?2015/52/4/502/178375
Colorectal carcinoma is rare in the pediatric age group with incidence of 1.3-2 cases/million children and is much lower in India. Microsatellite instability (MSI) is present in approximately 15% of colorectal cancers (CRC), which are mostly non-familial (sporadic) and caused by hypermethylation of the mutL homolog 1 (MLH1) promoter.
A 10-year-old male child presented with a swelling in the right iliac fossa, gradually increasing in size since 6 months and with pain since 1 month. General and hematological examinations were insignificant.
Systemic examination showed a palpable mass of size 3 cm × 4 cm × 2 cm in the right lower quadrant of the abdomen. The clinical diagnosis was Koch's abdomen with differential diagnosis of lymphoma. Fine-needle aspiration cytology [Figure 1] was suggestive of round cell malignancy suggestive of non-Hodgkin's lymphoma (NHL). Computed tomography abdomen showed a hypodense mass occupying the caecum and part of the ascending colon with iliac lymphadenopathy. Intraoperative findings revealed two tumors in the cecum and ascending colon of size 6 cm × 6 cm and 4 cm × 4 cm respectively.
|Figure 1: Fine-needle aspiration cytology suggestive of malignant pleomorphic tumor? Non-Hodgkin's lymphoma (Pap, ×10)|
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On gross [Figure 2], a segment of intestine of length 40 cm was received. Two masses, one in the cecum and the other in the ascending colon were seen on cut section. The cecal mass [Figure 3] was an endophytic growth of size 6 cm × 5 cm × 2 cm size with infiltrative margins. The ascending colon mass [Figure 4] was well-circumscribed, 4 cm × 3 cm × 2 cm in size with cut surface grayish white and gelatinous.
|Figure 3: Endophytic growth of 6 cm × 5 cm × 2 cm in the caecum with infiltrative margins|
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|Figure 4: Well-circumscribed, grayish white and gelatinous tumor of 4 cm × 3 cm × 2 cm size|
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The cecal tumor with endophytic growth [Figure 5] showed diffusely scattered round to oval cells with hyperchromatic nuclei and anisonucleosis, separated by thin fibrous septa. Areas of necrosis and calcification were also seen. The ascending colon tumor with a glistening surface [Figure 6] showed sheets and groups of cells with hyperchromatic nuclei, prominent nucleoli, admixed with mucin pools. The tumor was infiltrating all the layers of the large intestine.
|Figure 5: Diffusely scattered round to oval tumor cells separated by thin fibrous septa (H and E, ×10)|
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Lymph node [Figure 7] showed metastatic deposits of tumor cells.
A diagnosis of adenocarcinoma of the colon with NHL was made.
Immunohistochemistry revealed [Figure 8] a diffuse positivity for pan cytokeratin (CK) and [Figure 9] epithelial membrane antigen, focal positivity for CK20 [Figure 10] and vimentin [Figure 11] and negativity for CK7, CD99, CD45 (leukocyte common antigen) [Figure 12], synaptophysin and chromogranin, indicating that the tumor was an adenocarcinoma.
Further investigations like microsatellite markers were done and showed nuclear positivity for MutS homolog 2 [MSH2], MSH6, MLH1 and Postmeiotic segregation increased 2 [PMS2].
Immunoprofile showed mismatch repair protein proficient tumor, which is compatible with microsatellite stable tumor type.
The final diagnosis was given as invasive adenocarcinoma of colon (poorly differentiated and with microsatellite stable tumor type). Patient was lost for further follow-up.
| » Discussion|| |
The incidence of colorectal carcinoma in individuals younger than 20 years of age is less than0.1 cases per million. Delayed diagnosis, advanced stage of disease at presentation and most importantly mucinous type of histology are the major determinants of poor outcome in childhood colorectal carcinoma.
microsatellite instability-high is present in more than 90% of hereditary non-polyposis CRC, compared to only 15-20% of sporadic carcinoma.
| » Inference|| |
MSI tumors have a good prognosis and reduced likelihood of metastasis compared with microsatellite stable tumors, which highlights the value of MSI as a prognostic marker in CRC.
| » References|| |
Devendra K, Carachi R. Colorectal cancer in children. Pediatric Oncology. 1st
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Vilar E, Gruber SB. Microsatellite instability in colorectal cancer-the stable evidence. Nat Rev Clin Oncol 2010;7:153-62.
Walker WA. Clinical manifestations and management. The intestine. Paediatric Gastrointestinal Disease. Pathophysiology and Diagnosis. Hamilton: B.C. Decker; 2004. p. 989.
Ibrahim K, Arbay O, Ciftci, Mehmet E, Nebil B. Colorectal carcinoma in children. J Pediatr Surg 1999;34:1499-504.
Koch TR. Genetic testing for colon cancer. Colonic Diseases. New Jersey: Human Press; 2003. p. 200.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12]