Fallopian tube carcinoma mimicking inguinal hernia: A case report with imaging and histological insights.

We present the case of a woman in her 70s with painless multiple lymphadenopathies in the left supraclavicular and left axillary regions. The patient was referred to our hospital. Her past medical history included hysterectomy and right oophorectomy for uterine fibroids and an ovarian endometrioma 29 years previously. Blood tests revealed elevated levels of fibrinogen (428 mg/dL; reference range: 200–400 mg/dL), D-dimer (1.8 ng/mL; reference range: ≤1.0 ng/mL), cancer antigen 19-9 (CA19-9) (45.1 U/mL; reference range: <37U/mL), and cancer antigen 125 (CA125) (524 U/mL; reference range: <35 U/mL). A biopsy of the left supraclavicular lymph node suggested poorly differentiated adenocarcinoma. Computed tomography (CT) findings: Contrast-enhanced CT ( Fig. 1 ) revealed multiple enlarged lymph nodes and a tubular structure with solid components in the left pelvic region, showing a left inguinal hernia. Fig. 1 Abdominal contrast-enhanced computed tomography (axial view, arranged craniocaudally from a to b). A tubular structure with a solid component and intraluminal papillary projections is observed in the left lower abdomen (arrow). The structure extends along the left round ligament into the left inguinal canal, resulting in an external inguinal hernia (arrowhead). Fig 1: Abdominal contrast-enhanced computed tomography (axial view, arranged craniocaudally from a to b). A tubular structure with a solid component and intraluminal papillary projections is observed in the left lower abdomen (arrow). The structure extends along the left round ligament into the left inguinal canal, resulting in an external inguinal hernia (arrowhead). Magnetic resonance imaging (MRI) findings: Next, MRI ( Fig. 2 ) revealed that the solid part within the tubular structure was hypointense on T1-weighted images, isointense on T2-weighted images, and hyperintense on diffusion-weighted images, with an apparent diffusion coefficient of 0.9 × 10 −3 mm 2 /s. Fig. 2 Magnetic resonance imaging (MRI). (A) Axial T2-weighted images (T2WI), (B) axial T1-weighted images (T1WI), (C) diffusion-weighted images (DWI), (D) apparent diffusion coefficient (ADC) map, and (E) coronal T2WI. The solid component within the sausage-shaped structure (arrow) demonstrates iso-intensity on T2WI (A, E), low-intensity on T1WI (B), high-intensity on DWI (C), and low ADC value (D). Mild enhancement of the solid part is noted on gadolinium-enhanced images (not shown). The sausage-like or tubular structure represented the dilated fallopian tube, with the papillary to solid nodular part within the lumen indicating the carcinoma. The rest of the structure was dilated and filled with fluid. Fig 2: Magnetic resonance imaging (MRI). (A) Axial T2-weighted images (T2WI), (B) axial T1-weighted images (T1WI), (C) diffusion-weighted images (DWI), (D) apparent diffusion coefficient (ADC) map, and (E) coronal T2WI. The solid component within the sausage-shaped structure (arrow) demonstrates iso-intensity on T2WI (A, E), low-intensity on T1WI (B), high-intensity on DWI (C), and low ADC value (D). Mild enhancement of the solid part is noted on gadolinium-enhanced images (not shown). The sausage-like or tubular structure represented the dilated fallopian tube, with the papillary to solid nodular part within the lumen indicating the carcinoma. The rest of the structure was dilated and filled with fluid. Mild enhancement was noted with gadolinium contrast. Based on the tubular, sausage-like structure observed in CT and MRI along with the presence of a proliferative lesion extending into the lumen, we suspected FTC. Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT): Finally, FDG-PET/CT ( Fig. 3 ) revealed FDG uptake with a maximum standardized uptake value of 10.8 in the solid part of the left lower abdomen. PET revealed FDG uptake in multiple enlarged lymph nodes in the left supraclavicular, axillary, para-aortic, and pelvic regions, indicating lymph node metastasis. Based on lymph node biopsy and imaging findings, FTC with multiple metastases was suspected. Fig. 3 Positron emission tomography-computed tomography (PET/CT). (A) Maximum intensity projection (MIP) image, (B) PET-CT fusion image (level of the solid tumor), and (C) PET-CT fusion image (level of the inguinal hernia). The left MIP image (A) reveals multiple enlarged lymph nodes with FDG uptake in the left supraclavicular fossa, axilla, para-aortic region, and pelvis, showing lymph node metastasis. The solid part in the left lower abdomen (B, arrow) shows corresponding FDG uptake (SUV max of 10.8). Minimal FDG uptake is seen in the high-water-content sausage-shaped structure observed on MRI (C, arrowhead). The sausage-shape morphology is a characteristic of a dilated fallopian tube. The solid components within the lesion exhibit hypermetabolic activity and intense uptake, whereas the fluid or secretory components show weak uptake. Infiltrative shadows with FDG uptake are present in both lungs, which suggest exacerbated nontuberculous mycobacteriosis. Fig 3: Positron emission tomography-computed tomography (PET/CT). (A) Maximum intensity projection (MIP) image, (B) PET-CT fusion image (level of the solid tumor), and (C) PET-CT fusion image (level of the inguinal hernia). The left MIP image (A) reveals multiple enlarged lymph nodes with FDG uptake in the left supraclavicular fossa, axilla, para-aortic region, and pelvis, showing lymph node metastasis. The solid part in the left lower abdomen (B, arrow) shows corresponding FDG uptake (SUV max of 10.8). Minimal FDG uptake is seen in the high-water-content sausage-shaped structure observed on MRI (C, arrowhead). The sausage-shape morphology is a characteristic of a dilated fallopian tube. The solid components within the lesion exhibit hypermetabolic activity and intense uptake, whereas the fluid or secretory components show weak uptake. Infiltrative shadows with FDG uptake are present in both lungs, which suggest exacerbated nontuberculous mycobacteriosis. Surgical and Pathological Findings: Laparoscopic pelvic tumor resection was performed to confirm the histological type. Intraoperative findings included a cystic tumor in the left pelvis, which adhered to the omentum. The tubular structure extended into the inguinal canal and hernia sac. Histological examination of the resected specimen revealed a cystic lesion with a papillary part. Microscopic findings ( Fig. 4 ) confirmed that atypical cells proliferated in a nodular to papillary pattern. Immunohistochemistry was positive for paired box gene 8, cyclin-dependent kinase inhibitor 2A, and estrogen receptor, with partial positivity for progesterone receptor and a Mib-1 index of 80%. These findings confirmed the diagnosis of high-grade serous carcinoma. Although immunohistochemical staining could be consistent with ovarian or peritoneal origin, the presence of a papillary lesion predominantly located within the tubal lumen strongly suggested a fallopian tube origin in this case. The background of the papillary lesion exhibited nontumorous epithelium and smooth muscle, further supporting the tubal origin diagnosis. Fig. 4 Pathological diagnosis. Macroscopic findings, (A) surface image, (B) cut surface image, and (C) microscopic findings. (A) A cystic lesion with a central white solid part is observed (arrow). In the center of the image, a white solid nodule approximately 3 cm in size with central necrosis is visible (arrowhead). (B) The cut surface reveals an elevated papillary lesion in dilatated tubular structure (arrow). (C) Microscopic findings of a papillary lesion. The cells, accompanied by high-grade atypia, exhibit nodular to papillary growth patterns with invasive proliferation, accompanied by necrosis and hemorrhage. An ovary is found near this lesion, and in this area, a similar high-grade serous carcinoma with vascular invasion and invasion into surrounding tissues is observed (not shown). Fig 4: Pathological diagnosis. Macroscopic findings, (A) surface image, (B) cut surface image, and (C) microscopic findings. (A) A cystic lesion with a central white solid part is observed (arrow). In the center of the image, a white solid nodule approximately 3 cm in size with central necrosis is visible (arrowhead). (B) The cut surface reveals an elevated papillary lesion in dilatated tubular structure (arrow). (C) Microscopic findings of a papillary lesion. The cells, accompanied by high-grade atypia, exhibit nodular to papillary growth patterns with invasive proliferation, accompanied by necrosis and hemorrhage. An ovary is found near this lesion, and in this area, a similar high-grade serous carcinoma with vascular invasion and invasion into surrounding tissues is observed (not shown). Based on these findings, the diagnosis was FTC with multiple lymph node metastases, International Federation of Gynecology and Obstetrics [ 4 ] stage IVB. Subsequently, chemotherapy was administered.

Informed consent was obtained for the publication of this case report.

We report a case of FTC presenting as a left inguinal hernia. Recognizing the possibility of fallopian tube involvement in inguinal hernia contents and becoming familiar with the imaging characteristics of FTC can facilitate an easier and correct diagnosis.

Fallopian tube malignancies are rare; however, histological, molecular, and genetic evidence suggests that up to 80% of tumors classified as high-grade serous carcinomas of the ovary or peritoneum originate from the fimbrial end of the fallopian tube [ 5 ]. The classic symptoms of FTC include (1) intermittent blood-tinged or watery discharge, (2) lower abdominal pain relieved by discharge, and (3) a palpable pelvic or abdominal mass [ 6 ]. However, <15% of patients are present with these symptoms [ 7 ]. Thus, fallopian tube tumors are often diagnosed at an advanced stage and are associated with a high mortality rate [ 8 ]. Determining CA125 levels is useful for preoperative diagnosis, with approximately 80% of patients showing elevated levels [ 9 ]. Imaging characteristics of FTC, regardless of stage, include sausage-, serpentine-, or gourd-shaped cystic or solid masses [ 10 ]. MRI findings typically reveal homogenous signals with mild-to-moderate enhancement on gadolinium-enhanced images, often accompanied by hydrosalpinx or uterine fluid accumulation [ 11 ]. Ovarian, fallopian tube, and primary peritoneal cancers share very similar clinical characteristics, response to debulking surgery, and chemosensitivity. Thus, the same treatment approach can be applied to all 3 diseases. As a result, the staging classification and treatment strategies used for PFTC, including cytoreductive surgery and adjuvant chemotherapy, are similar to those used for epithelial ovarian cancer [ 12 ]. Regarding debulking surgery, Robert E. Bristow et al. reported that maximal cytoreductive surgery was a powerful predictor of cohort survival in patients with stage III or IV ovarian cancer [ 13 ]. The lifetime risk of inguinal hernia in women ranges from 3% to 5.8% [ 1 ]. In adult women, in only 2.9% of cases, the hernia sac contains the fallopian tube and ovary [ 2 ]. Inguinal hernia contents may include not only intestinal and fatty tissue but also other pathological entities. These include lipomas, dermoid cysts, endometriosis, uterine leiomyomas, ovarian cysts, bladder diverticula, and malignancies [ [14] , [15] , [16] ]. Malignant tumors presenting in inguinal hernias have been reported to occur in <0.4% of cases [ 3 ]. Fallopian tube cancer spreads through the hematogenous, lymphatic, and peritoneal routes. Notably, the cancer cells can directly extend into the pelvis. Lymph node metastases primarily occur in the pelvic and aortic regions; however, metastases beyond the pelvis and abdomen are relatively rare [ 8 ]. In a case reported by Maria Lúcia Moleiro et al., metastasis to the supraclavicular lymph node was the initial symptom of fallopian tube cancer [ 17 ]. In this case, pelvic imaging did not reveal an obvious primary lesion. Therefore, biopsy of the para-aortic lymph node was performed, which confirmed metastasis of high-grade serous carcinoma (HGSC). An elevated CA125 level (898 U/mL) was also observed. Diagnostic laparoscopy led to hysterectomy and bilateral adnexectomy, and a small 1.5-mm HGSC was confirmed in the fallopian tube through pathological examination [ 17 ]. In the case reported by Jui-Chun Chang et al., seeding from fallopian tube cancer involving the greater omentum presented as an inguinal hernia, with an inguinal mass as the initial symptom [ 18 ]. Imaging of the inguinal mass did not clearly reveal the contents of the hernia; therefore, exploratory laparotomy was performed. Macroscopically, no significant abnormalities were observed in the bilateral ovaries or fallopian tubes. However, pathological examination of the disseminated nodules in the abdomen revealed high-grade metastatic serous carcinoma. The final pathological results confirmed serous and intraepithelial carcinomas of the right fallopian tube. Furthermore, the patient exhibited elevated CA125 levels (CA125: 159 U/mL) [ 18 ] Common features between these cases and our case were elevated CA125 levels and the absence of typical lymph node metastases or symptoms. However, a notable difference was that preoperative imaging revealed typical findings suggestive of primary fallopian tube cancer. In our case, the characteristic imaging findings of fallopian tube cancer made diagnosis easier. However, as other case reports have shown, even in the absence of typical imaging findings, hernia contents, or classic lymph node metastases, gynecological tumors, such as fallopian tube cancer, can be involved, and this possibility must be considered. The mechanism underlying FTC presenting as an inguinal hernia in this patient may be related to increased mobility of the left adnexa following hysterectomy and right oophorectomy. Adhesions and tumor infiltration near the left inguinal canal may have partially fixed the left adnexa, leading to herniation due to increased intraluminal pressure from tumor growth.

The lifetime risk of inguinal hernia in women ranges from 3% to 5.8% [ 1 ]. Typically, the hernia sac contains part of the omentum or small intestine; however, in 2.9% of cases, it contains the fallopian tube and ovary [ 2 ]. Malignancies within the hernia sac are rare, with an incidence of <0.4% [ 3 ]. In contrast, fallopian tube carcinoma (FTC) is a rare but aggressive gynecological malignancy, accounting for approximately 0.3%–1.8% of all female genital tract cancers [ [4] , [5] , [6] , [7] ]. Despite its low incidence, FTC is associated with a high mortality rate, primarily because of its propensity for late-stage diagnosis and aggressive biological behavior [ 8 ]. The most common presenting symptoms are pelvic or abdominal pain, abnormal vaginal bleeding, and adnexal mass [ [4] , [5] , [6] , [7] ]. Although FTC can spread through direct extension or hematogenous dissemination, lymphatic metastasis is also a common route of spread [ 4 , 5 , 7 ]. Consequently, FTC presentation within an inguinal hernia is extremely rare. We report the case of a woman with FTC that presented as an inguinal hernia. Furthermore, we conducted a brief review of the literature.