Rhabdoid tumor, first described by Beckwith in 1978 as an aggressive kidney tumor in infants and children and defined it as the rhabdomyosarcomatoid subtype of Wilms’ tumor [1,2]. The tumor has also been reported in extra-renal locations, most often in the head, neck, urogenital tracts and skeletal system. However, they have also been described in the skin, brain, mediastinum, liver and other peritoneal structures especially in the adult age group, albeit very rarely. Their occurence in the gastrointestinal system is exceptionally rare [2]. Rhabdoid tumor makes up 0.1-0.2% of all gastric carcinomas [3]. We describe the case of a 67 year old female patient with gastric adenocarcinoma composed of histologically well differentiated glandular areas, extensive rhabdoid zones and regions depicting a transition between these two constituents.

A 67 years female presented with complaints of pain epigastrium and vomiting since one month. CECT abdomen showed irregular circumferential enhancing thickening at antropyloric region and lesser curvature of stomach with significant luminal narrowingand enlarged subcentrimetric/suprapancreatic lymph nodes. On upper GI endoscopy, a large ulcero proliferative growth was seen at incisura and extending up to the pylorus. Biopsy from the ulcer was suggestive of an adenocarcinoma. Distal radical gastrectomy was performed.

On gross examination, there was a large ulceroproliferative growth (4×4×2 cm) in the pyloric region. Cut section of growth was grey white and reaching upto the serosa (Figure 1). Microscopic examination of growth predominantly showed diffuse sheets of round to polygonal cells with eccentrically placed vesicular nuclei, prominent nucleoli and abundant dense eosinophilic cytoplasm (Figure 2). Bizarre tumor giant cells, paranuclear eosinophilic inclusions and lymphovascular invasion were also noted. Frequent atypical mitotic figures were seen. There were focal areas revealing well differentiated adenocarcinoma (Figure 3) and regions depicting a transition between these two constituents.

Figure 1: Distal Gastrectomy Specimen Revealing Ulceroinfiltrative Growth

Figure 2: Rhabdoid Tumor Cells with Eccentrically Placed Vesicular Nuclei, Prominent Nucleoli and Abundant Dense Eosinophilic Cytoplasm (H&E, 40x)

Figure 3: Photomicrograph Showing Rhabdoid Area as Well as Well Differentiated Adenocarcinoma (H&E, 20x)

Multiple lymph nodes dissected out from the specimen showed metastatic tumor deposits. Periodic acid-Schiff staining showed mucin in the glandular tumor cells but not in the rhabdoid tumor cells. On immunohistochemistry the tumor cells were positive for both vimentin (Figure 4) and cytokeratin. Diagnosis of well differentiated Gastric Adenocarcinoma with extensive rhabdoid areas was given.

Gastrointestinal malignant rhabdoid tumors are very rare and are reported in the esophagus, stomach, small intestine, colon, pancreas and hepatobiliary tract [4-6]. Rhabdoid tumor makes up 0.1-0.2% of all gastric carcinomas [3]. Nearly 17 cases have been reported in stomach to date [7-13].

Figure 4: Vimentin Positivity in Rhabdoid Tumor Cells (IHC, 40x)

In the stomach, rhabdoid tumors are most commonly seen in males with advanced age and are characterized by either gastrointestinal bleeding or large, ulcerated masses [2]. In most patients, remote metastasis develops shortly after diagnosis. The metastatic invasion pattern is multiple and in the form of transmural tumor implants in the duodenum and small intestine [4].

Rhabdoid morphology is composed of large polygonal cells with eccentric location and vesicular nuclei. Thesecells contain eosinophilic, hyaline globular inclusions atparanuclear locations that have pushed the nucleus aside in their cytoplasms. These inclusions develop as a result of the band- and coil-shaped accumulation of intermediate filaments and show both vimentin and cytokeratinimmunore activity. The determination of cytokeratin and vimentin positivity in cells with the rhabdoid morphologyis crucial for differential diagnosis which includes GIST, sarcoma, malignant melanoma and lymphoma [5,6].

In the present case, microscopic examination revealed gastric adenocarcinoma composed of histologically well differentiated glandular areas as well as extensive rhabdoid zones and regions depicting a transition between these two constituents. Similar findings were noted by Pinto et al. [12] in their case. They suggested that the rhabdoid areas probably represent a phenotypic variant of a gastric adenocarcinoma, otherwise fairly well differentiated, a combination which was not previously reported.

Cytogenetic studies have discovered a mutation of the Hsnf5/INI1 gene, located on chromosomal band 22q11.2, in renal RT and ERRT [14]. Accordingly, the INI1 gene seems to be a tumor suppressor involved in both RT and ERRT. Hoot et al. [15] reported that INI1 gene mutations were not present in five of 19 RTs and one of eight ERRTs in children. ERRT, in addition to INI gene mutations, might also be caused by the loss of INI protein function or by other, still unknown factors

Ueyama et al. [8] identified only 4 patients among 5437 gastric carcinoma cases who had this morphology. These tumors have a very poor prognosis in a way similar to primary renal rhabdomyosarcoma and they have a very aggressive clinical course [16]. It is stated that these 4 rhabdoid tumor patients died within 6 months due to the disease.

Thus based on a retrospective literature review, it was observed that gastric carcinoma patients with such morphology survive less than one year [17]. In our case also, the tumor was widespread at the time of diagnosis and the patient died within six months despite treatment, thus confirming an aggressive biological behavior of such tumors.

In conclusion, recognition of the rhabdoid phenotype in gastrointestinal tract neoplasms is important because this feature is associated with poor prognosis and unresponsiveness to conventional therapy.

1. Lee J.R. et al. “Malignant Rhabdoid Tumor of the Duodenum.” Annals of Diagnostic Pathology, vol. 2, no. 1, February 1998, pp. 25-30.

2. Amrikachi M. et al. “Adenocarcinomas of the Gastrointestinal Tract with Prominent Rhabdoid Features.” Annals of Diagnostic Pathology, vol. 6, no. 6, December 2002, pp. 357-363.

3. Lauwers G.Y. “Epithelial Neoplasms of the Stomach.” Surgical Pathology of the GI Tract, Liver, Biliary Tract and Pancreas, edited by R.D. Odze, J.R. Goldblum and J.M. Crawford, Elsevier Saunders, 2004, pp. 409-427.

4. Mastoraki A. et al. “Malignant Rhabdoid Tumor of the Large Intestine.” International Journal of Colorectal Disease, vol. 24, no. 11, November 2009, pp. 1357-1358.

5. Ng W.C. et al. “Malignant Rhabdoid Tumour of the Oesophagus: A Case Report.” Journal of Clinical Pathology, vol. 56, no. 9, September 2003, pp. 713-714.

6. Sheikh S.S. et al. “Metachronous Malignant Rhabdoid Tumor of the Ileum and Adenocarcinoma of Lung: A Unique Case Report.” Annals of Diagnostic Pathology, vol. 12, no. 1, February 2008, pp. 57-61.

7. Öfkeli O. et al. “Malignant Rhabdoid Tumour in the Stomach.” Ulus Cerrahi Derg, vol. 31, 2015, pp. 55-57.

8. Ueyama T. et al. “Vimentin-Positive Gastric Carcinomas with Rhabdoid Features: A Clinicopathologic and Immunohistochemical Study.” The American Journal of Surgical Pathology, vol. 17, no. 8, August 1993, pp. 813-819.

9. Utsunomiya T. et al. “Vimentin-Positive Adenocarcinomas of the Stomach: Co-expression of Vimentin and Cytokeratin.” Histopathology, vol. 29, no. 6, December 1996, pp. 507-516.

10. Utsunomiya T. et al. “Intracellular Distribution of Intermediate Filaments in Vimentin-Positive Gastric Carcinomas: Confocal Laser Scanning Microscopy Using Formalin-Fixed Paraffin-Embedded Specimens.” Pathology-Research and Practice, vol. 198, no. 2, January 2002, pp. 69-76.

11. Read H.S. et al. “Malignant Rhabdoid Tumour of Stomach.” Histopathology, vol. 29, no. 5, November 1996, pp. 474-477.

12. Pinto J.A. et al. “Well-Differentiated Gastric Adenocarcinoma with Rhabdoid Areas: A Case Report with Immunohistochemical Analysis.” Pathology-Research and Practice, vol. 193, nos. 11-12, January 1997, pp. 801-805.

13. Sharma S. et al. “Mucin-Secreting Gastric Adenocarcinoma with Rhabdoid Areas.” Saudi Journal of Gastroenterology, vol. 16, no. 1, January 2010, pp. 46-48.

14. Biegel J.A. et al. “Germ-line and Acquired Mutations of INI1 in Atypical Teratoid and Rhabdoid Tumors.” Cancer Research, vol. 59, no. 1, January 1999, pp. 74-79.

15. Hoot A.C. et al. “Immunohistochemical Analysis of hSNF5/INI1 Distinguishes Renal and Extra-renal Malignant Rhabdoid Tumors from Other Pediatric Soft Tissue Tumors.” The American Journal of Surgical Pathology, vol. 28, no. 11, November 2004, pp. 1485-1491.

16. Parham D.M. et al. “The Clinicopathologic Spectrum of Putative Extrarenal Rhabdoid Tumors: An Analysis of 42 Cases Studied with Immunohistochemistry or Electron Microscopy.” The American Journal of Surgical Pathology, vol. 18, no. 10, October 1994, pp. 1010-1029.

17. Rivera-Hueto F. et al. “Early Gastric Stump Carcinoma with Rhabdoid Features: Case Report.” Pathology-Research and Practice, vol. 195, no. 12, January 1999, pp. 841-846.