|LETTER TO EDITOR
|Year : 2022 | Volume
| Issue : 1 | Page : 56-57
Oncocytic variant of gastrointestinal stromal tumor of jejunum masquerading as uterine mass
Department of Pathology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
|Date of Submission||30-Dec-2021|
|Date of Decision||22-Feb-2022|
|Date of Acceptance||24-Feb-2022|
|Date of Web Publication||15-Jun-2022|
Dr. Kavita Mardi
Set No. 14, Type VI Quarters, IAS Colony, Meheli, Shimla, Himachal Pradesh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Mardi K. Oncocytic variant of gastrointestinal stromal tumor of jejunum masquerading as uterine mass. Ann Oncol Res Ther 2022;2:56-7
|How to cite this URL:|
Mardi K. Oncocytic variant of gastrointestinal stromal tumor of jejunum masquerading as uterine mass. Ann Oncol Res Ther [serial online] 2022 [cited 2022 Jun 25];2:56-7. Available from: http://www.aort.com/text.asp?2022/2/1/56/347559
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Most GISTs show a spindled, epithelioid, or mixed (spindle/epithelioid) cell morphology. Oncocytic variant of GIST is rare and is characterized by the presence of abundant mitochondria. We describe one such rare case of oncocytic GIST arising from jejunum which masqueraded as a uterine mass in a 66-year-old female who presented with mild pain in lower abdomen for 4 months which was insidious in onset. On per abdominal examination, there was a vague lump in the lower abdomen in the hypogastrium measuring 10 cm × 10 cm in size extending into the pelvis. This abdominal lump had smooth surface, rounded margins, firm consistency, and was not moving with respiration. The lumps were not fixed to the overlying skin or underlying structures.
Fine-needle aspiration of the abdominal lump done before computed tomography (CT) scan revealed cellular smears comprising pleomorphic oncocytic cells with abundant densely basophilic cytoplasm. These cells were admixed with occasional spindle cells. Binucleate cells were also seen [Figure 1] CT scan revealed a large lobulated solid heterogeneously enhancing mass arising from the pelvis in midline infiltrating into the right uterine walls likely to be arising from the ovary. The patient underwent laparotomy without any neoadjuvant chemotherapy. Perioperatively, there was a large lobulated mass measuring 14 cm × 12 cm × 11 cm arising from the uterus densely adherent to the jejunum. Growth was excised along with the adherent segment of the jejunum along with the uterus, bilateral Fallopian tube, and other side ovary. On gross examination, there was a large mass measuring 11 cm × 11 cm × 8 cm with bosselated outer surface, tan brown cut surface. The mass was arising from the wall of the jejunum and was adherent to the serosal surface of the uterus [Figure 2]. Microscopic examination of the sections from growth revealed predominantly sheets and nests of pleomorphic round to polygonal cells with abundant densely eosinophilic cytoplasm. The tumor nuclei were irregular/lobulated hyperchromatic with occasional intranuclear inclusions [Figure 3]. Focal area revealed intersecting fascicles of plump spindle cells. Less than five mitotic figures per 50 high-power fields were identified. Focal areas of necrosis were also seen. The tumor was invading into serosa and outer half of the myometrium of the uterus. Both ovaries were free from tumors. Keeping in view these gross and microscopic findings, diagnosis of oncocytic variant GIST (high-risk category) was rendered. On IHC, the tumor cells were positive for CD117, DOG 1, and CD34.
|Figure 1: Fine-needle aspiration smears revealing oncocytic cells as well as spindle cells (Giemsa, ×40)|
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|Figure 2: Gross specimen revealing large lobulated mass attached to the serosal surface of the uterus|
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|Figure 3: Photomicrograph revealing sheets and nests of pleomorphic round to polygonal cells with abundant densely eosinophilic cytoplasm (H and E, ×40)|
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Differential diagnosis includes metastatic hepatocellular carcinoma, metastatic eosinophilic variant of clear cell renal cell carcinoma (RCC), metastatic Hurthle cell carcinoma thyroid, metastatic sex cord-stromal tumor, and melanoma. A wide IHC panel including the markers CD117, CD34, DOG 1, CK, EMA, melan A, glypican, Hep Par 1, PAX 8, thyroglobulin, TTF-1, and inhibin helps in diagnosis. Positivity for CD117, DOG1, CD34 while negativity for other markers is characteristic for this tumour. Hepatocellular carcinoma is positive for glypican and Hep Par 1. Metastatic eosinophilic variant of clear cell RCC is positive for PAX8. Metastatic Hurthle cell carcinoma thyroid, metastatic sex cord-stromal tumor, and melanoma show positivity for TTF-1/thyroglobulin, inhibin, and melan A, respectively.
Goswmi described a rare case of oncocytic GIST arising from the small intestine which showed Cytokeratin expression in addition to C-kit, DOG-1, and CD34 expression. Damiani et al. described two cases of GISTs with prominent oncocytic features. Both had features consistent with differentiation toward the interstitial cells of Cajal (CC). They were composed of nests and bundles of cells with abundant, deeply granular, eosinophilic cytoplasm. Immunohistochemically, both cases revealed positivity with c-kit, vimentin, and CD34 antibodies. Ultrastructurally, the neoplastic cells showed characteristic features of CC; they had synapse-like structures and dense core cytoplasmic granules. Oncocytic features were confirmed by immunohistochemistry using an anti-mitochondrion antibody in both cases.
In conclusion, we describe a rare oncocytic GIST arising from the jejunum which mimicked a uterine tumor radiologically and on gross examination. Histological and IHC findings helped in arriving at final diagnosis. The importance of oncocytic differentiation in GIST is not yet known. More cases need to be documented to know their impact on prognosis.
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.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]