Unravelling an uncommon cause of abdominal pain in a young female: A rare case report

Introduction Krukenberg tumor (KT) is a rare metastatic signet ring cell tumor of the ovary, constituting approximately 1%–2% of all ovarian malignancies. It was first described by Friedrich Ernst Krukenberg in 1896.[1] KT originates from a primary malignancy, most commonly from the stomach.[2] The tumor is bilateral in approximately 80% of cases and predominantly affects perimenopausal women. Reports of KT in young females are rare. Here, we present the case of an 18-year-old female with KT, highlighting the diagnostic challenges and the need for early detection in young patients with bilateral ovarian masses. Case Report An 18-year-old female presented to the gynecology outpatient department with complaints of abdominal pain for 2 months. Her past medical history was unremarkable except for hypothyroidism, for which she had been on medication for the past 2 months. Her menstrual cycles were regular and there were no prior gynecological symptoms. General examination and vital signs were normal. Abdominal examination revealed a hard and nontender mass with an irregular margin and restricted mobility, extending into the left lumbar and right iliac regions. There were no other associated symptoms. Laboratory investigations were largely within normal ranges except for marginally elevated serum glutamic oxaloacetic transaminase, serum glutamate pyruvate transaminase, and gamma-glutamyl transferase levels (42.8/78.1/58.7 U/L, respectively). Serum markers such as lactate dehydrogenase and alpha-fetoprotein were within the normal limits. Ultrasound of the abdomen revealed a large, well-defined, lobulated, and heteroechoic mass with internal vascularity arising from the anterior fundal region, measuring 16 cm × 16 cm × 5.8 cm, initially suspected to be a subserosal fibroid. Magnetic resonance imaging (MRI) of the abdomen and pelvis revealed large, well-defined, and lobulated solid masses in both adnexa, abutting each other at the midline. The right adnexal mass measured 16.5 cm × 9.7 cm × 8 cm and the left measured 12.5 cm × 8.4 cm × 5.6 cm, suggesting a likely ovarian origin (fibroma/thecoma). Exploratory laparotomy was performed, followed by bilateral salpingo-oophorectomy. The specimens consisted of two globular structures measuring 13 cm × 10 cm × 2 cm and 17 cm × 9 cm × 4.5 cm with attached fallopian tubes. Both masses had a well-defined outer contour with bosselation. The cut section was gray-white, homogeneous, and solid, without necrosis or cystic changes [Figure 1a]. Microscopic examination revealed a capsulated tumor with tumor cells arranged in nests, vague acinar patterns, trabeculae, and scattered singly within an abundant desmoplastic stroma. The cells were polygonal, with eosinophilic cytoplasm and hyperchromatic, centrally, or eccentrically placed nuclei. Numerous signet ring cells were observed [Figure 1b]. PAS staining confirmed the presence of cytoplasmic mucin [Figure 1c]. The fallopian tubes were histologically unremarkable. Based on these findings, a diagnosis of KT was made, warranting further investigation for the primary malignancy. Fluorodeoxyglucose-positron emission tomography-computed tomography (FDG-PET-CT) revealed nonhypermetabolic diffuse wall thickening in the gastric fundus and proximal body, with minimal ascites but no hypermetabolic abnormalities elsewhere [Figure 2]. Upper gastrointestinal endoscopy showed a diffuse infiltrative growth from the gastroesophageal junction, involving the gastric fundus and body circumferentially. Colonoscopy was unremarkable. Biopsy from the gastric mass revealed poorly differentiated adenocarcinoma with signet ring cell morphology [Figure 1d]. Immunohistochemistry confirmed CK7 positivity, while CK20, PAX8, WT1, Her2neu, CA-125, and CDX-2 were negative, supporting the diagnosis of gastric-origin KT [Figure 3]. The postoperative course was uneventful. The patient was discharged on the seventh postoperative day and was referred to the oncology department for further evaluation and initiation of systemic chemotherapy. At the 10-month follow-up, she remained clinically stable with no new symptoms. The recent PET CT shows no evidence of any hypermetabolic foci.

Ovarian metastases present a significant diagnostic challenge due to their ability to mimic the clinical and morphological features of primary ovarian tumors and often complicate accurate diagnosis and appropriate treatment planning. A considerable proportion of ovarian metastases originate from adenocarcinomas of the gastrointestinal tract, with KT most commonly arising from gastric adenocarcinomas.[3] Other primary sites associated with KT include the breast, appendix, colon, small intestine, rectum, urinary bladder, gallbladder, biliary tract, pancreas, ampulla of Vater, and uterine cervix.[4] The diagnosis of KT is based on the World Health Organization diagnostic criteria, which require the presence of ovarian stromal infiltration, mucin-producing signet ring cells, and sarcomatous hyperplasia of the ovarian stromal tissue. The presence of signet ring cells is a key diagnostic feature. KT is selectively metastatic, predominantly forming along the gastric-ovarian metastatic axis.[5] They may present synchronously with the primary tumor or metachronously, appearing months or even years after the primary diagnosis. In some cases, KT may be the first manifestation of malignancy, with an initially unknown primary site.[3] In approximately 80% of cases, KT presents with bilateral ovarian enlargement, characterized by a bosselated contour. The ovarian capsule is usually intact and free from metastatic deposits.[6] Gastric cancer can metastasize selectively to the ovaries without involving other tissues, although the exact metastatic mechanisms remain unclear. Three possible metastatic pathways have been proposed: lymphatic spread, hematogenous (bloodborne) dissemination, and transcoelomic (abdominal implantation) metastasis.[6] Comprehensive imaging and endoscopic evaluation are essential in cases of bilateral ovarian masses, even in young patients. Imaging studies, including ultrasound and MRI, can aid in distinguishing metastatic ovarian tumors from primary ovarian neoplasms. Radiologically, KT typically appears as bilateral ovarian masses on abdominal pelvic sonography and CT scans. They are predominantly solid but may have cystic components. Sonographically, their presentation varies depending on the primary tumor site. Tumors originating from the stomach or breast tend to be solid, whereas those from the colon, rectum, appendix, or biliary tract commonly exhibit mixed solid and cystic features. Predominantly, cystic KT is less common and is typically associated with primary tumors of the colon or appendix.[3] Definitive diagnosis relies on histopathology. Immunohistochemical markers, such as CK7 positivity and CK20/CDX-2 negativity, help differentiate KT from primary ovarian mucinous tumors. The aggressive nature of KT, coupled with their often late-stage detection, results in a poor prognosis. They predominantly affect premenopausal women, with an average age of onset between 40 and 45 years. Cases in younger females are exceedingly rare and the present case adds to the existing literature. The rarity of this case is further underscored by the infrequency of gastric cancer in young women, as only 0.4%–0.5% of gastric cancers occur in women under 30 years of age.[7] To our knowledge, this is among the few reported cases of gastric-origin KT in a teenager, underscoring the exceptional rarity of this presentation. At the time of diagnosis, KT is typically classified into stage IV disease, with a median survival of approximately 14 months despite surgical and systemic treatments.[8] Given the poor prognosis associated with KT, early recognition of KT in young females is crucial. The rarity of KT in younger patients and its nonspecific presentation such as abdominal pain, bloating, and menstrual irregularities often leads to diagnostic delays, as primary ovarian tumors are more frequently considered in this demographic. Prognosis is notably worse when the primary tumor is identified after the detection of ovarian metastases.

This case highlights that even in adolescents, bilateral solid ovarian masses should raise the suspicion for metastatic disease, and timely histopathological evaluation is critical for management. An integrated multidisciplinary approach remains essential to ensure the optimal outcomes. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Acknowledgment The authors acknowledge Dr Angel Hembram, Assistant Professor, Department of Nuclear Medicine, KIMS, for providing the FDG PET CT images.

Adenocarcinoma; fluorodeoxyglucose-positron emission tomography-computed tomography; Krukenberg tumor; ovarian metastasis; signet ring cells; young female