Inguinal lymph node metastasis in treated breast cancer: an extremely rare presentation and review of literature

Abstract

Metastasis to inguinal lymph nodes from breast cancer is extremely rare and only a handful of cases have been reported in the literature to date. We report a case of a postmenopausal female patient who was a treated case of right breast cancer and developed inguinal metastases after 9 months. An excisional biopsy of the lesion confirmed the diagnosis. A positron emission tomography–CT scan revealed retropectoral and pelvic lymphadenopathy. The patient was treated with palliative radiotherapy to the inguinal and pelvic regions followed by palliative chemotherapy. The patient survived for 4 months after the detection of inguinal metastasis.

Background

Worldwide, breast cancer has the highest incidence among all cancers (11.7%). Still, it is only the fourth highest contributor to cancer deaths (6.9%), thanks to the advancements in management. In India, it is the highest in terms of both incidence and mortality.¹ Screening helps in the early detection of breast cancer and decreases mortality.² The management of breast cancer has undergone a revolutionary change in the past 50 years. The treatment paradigm has always been multimodal which includes surgery, chemotherapy, radiotherapy, biological response modifiers, hormone therapy and immunotherapy.³ The most common sites of metastases in breast cancer are bone, lung, liver and brain.⁴ Triple-negative tumours have more propensity towards visceral metastases.⁵ Malignancies arising from the skin of the lower extremity, cervix, vulva and anorectum often are associated with inguinal lymphadenopathy.⁶ Inguinal lymphadenopathy from a breast primary is a rare occurrence.

Here we report a case of treated breast cancer with metastatic inguinal lymphadenopathy and a review of the literature.

Case presentation

A postmenopausal woman in her early 50s, with no known comorbidities, nonsmoker, with no family history of cancer, no surgical history presented with the chief complaint of a lump in the right breast for 3 months. On clinical evaluation, there was a hard, nontender mass of size 3 cm × 2 cm in the upper outer quadrant of the right breast with multiple and matted right axillary lymphadenopathy. Mammography of bilateral breasts revealed a Breast Imaging-Review and Data System (BI-RADS) IV C lesion of size 2.8 cm × 1.9 cm in the right breast.⁷ Contrast-enhanced CT (CECT) scan of thorax, abdomen, pelvis and whole-body bone scan were done, which ruled out visceral and bone metastases. Core needle biopsy from the breast lump showed infiltrating ductal carcinoma—no specific type and on immunohistochemistry, it was found to be oestrogen receptor (ER) negative, progesterone receptor (PR) negative and Her 2 neu negative. The final diagnosis of the patient was carcinoma right breast cT2N2aM0 (stage IIIA).⁸ After discussion in multidisciplinary tumour board, the patient was started on neoadjuvant chemotherapy injection paclitaxel 175 mg/m² and injection carboplatin area under the curve 6. She received chemotherapy every 3 weekly intervals for six cycles. On clinical evaluation, there was a partial response to chemotherapy. Then she underwent modified radical mastectomy of the right breast. Postoperative histopathology showed no residual tumour in the breast, 6 axillary lymph nodes were positive for malignancy among the 25 harvested, and 2 of them had extranodal extensions. So, the pathological stage was ypT0N2Mx. Adjuvant radiotherapy was delivered to the right-side chest wall, axilla and supraclavicular fossa to a dose of 50 Gy in 25 fractions over 5 weeks by three-dimensional conformal radiotherapy (3DCRT) which was completed with minimal toxicity. The patient was subsequently advised for tablet capecitabine 1250 mg/m² daily in two divided doses. But the patient was reluctant for any further treatment because of the financial strain created by the prolonged treatment. So, she was kept on regular follow-up.

After 5 months of completion of treatment, the patient presented with complaints of pain and swelling in the right groin. On examination, a 2 cm × 1 cm size mobile, nontender swelling was palpated in the right inguinal region (figure 1). Bilateral lower limb examination and gynaecological examination revealed no abnormalities.

Figure 1.

Inguinal lymphadenopathy of size 2 cm × 1 cm.

Investigations

CECT abdomen and pelvis showed a 2 cm × 1.5 cm right inguinal lymph node (figure 2). An excisional biopsy was done from the inguinal mass that showed total replacement by a metastatic tumour which was morphologically consistent with breast carcinoma and immunohistochemistry was ER negative, PR negative and Her 2 neu negative (figures 3 and 4). Colonoscopy was done which was found to be normal. A whole-body 18 fluorodeoxyglucose (18-FDG) positron emission tomography–CT scan was done to rule out other systemic metastases. There were increased FDG uptake in the right deep pectoral and right iliac group of lymph nodes indicating disseminated nodal metastases while viscera and bones were free (figures 5 and 6). The patient was given option to test breast cancer gene 1 and 2 (BRCA 1 and 2). But the patient could not afford the test.

Figure 2.

Contrast-enhanced CT scan showing multiple right side inguinal lymphadenopathy, largest 2 cm × 1.5 cm.

Figure 3.

Histopathology from right inguinal lymph node showing total replacement by a metastatic tumour (H&E stain, 200×).

Figure 4.

Histopathology from right inguinal lymph node. The tumour cells are in solid nests. They show high nuclear-cytoplasmic ratio, marked nuclear pleomorphism along with mitosis and necrosis. Morphologically it is consistent with a metastatic breast carcinoma (H&E stain, 400×).

Figure 5.

Positron emission tomography–CT scan showing right deep pectoral node of size 2.1 cm × 1.6 cm with maximum standard uptake value—16.7.

Figure 6.

Positron emission tomography–CT scan showing mild fluorodeoxyglucose uptake is seen in few right external iliac lymph nodes, largest 1.5 cm × 0.8 cm with maximum standard uptake value—5.1.

Treatment

The patient then received palliative radiotherapy to the right inguinal and pelvic region (iliac and obturator group of lymph nodes) of 20 Gy in five fractions by mixed energy (6 and 15 MV) photon (Elekta Versa HD linear accelerator) (figure 7). Four weeks after completion of palliative radiotherapy, the patient was again evaluated clinically. There was a significant reduction of pain in the right inguinal area (>60% reduction compared with that of pre-radiotherapy). Then palliative chemotherapy of tablet capecitabine 1000 mg/m² two times per day for 14 days in a 3 weekly cycle was started.

Figure 7.

Three-dimensional conformal radiotherapy plan for palliative radiotherapy to right inguinal and pelvic region showing Planning Target Volume (PTV) covered by 95% of prescribed dose.

Outcome and follow-up

After three cycles of chemotherapy, the general condition of the patient deteriorated. She developed repeated vomiting, headache and seizures for which osmotic diuretics (glycerol) and steroids (dexamethasone) were prescribed suspecting brain metastases. Finally, the patient succumbed to the disease.

Discussion

Metastatic breast cancer is the spread of disease to sites other than the breast, chest wall and regional draining lymph nodes. The routes of spread include the haematogenous and lymphatic pathways. The most common sites of metastases include bone, lung, liver and brain.⁴ Malignancies of the lower extremity, cervix, vulva, skin of trunk and anorectum usually have more propensity towards inguinal lymph node involvement. Metastasis to inguinal lymph nodes from breast cancer is extremely rare. So far, only six cases have been documented in the English scientific literature.^9–13

Our patient developed inguinal metastasis after 9 months of completion of locoregional treatment. The metastatic site was ipsilateral to the primary and the presentation was pain and swelling. Except for one case,¹² all the other documented cases presented with ipsilateral inguinal metastasis. Also, the presenting complaints were predominantly lower limb swelling and pain. Inguinal metastasis was present at the time of diagnosis of primary disease in four cases.^{10 12 13} In the rest, metastasis happened after 2 years¹¹ and 6 years⁹ of treatment completion.

In our case, there was right deep pectoral and right iliac metastases in addition to the inguinal metastasis. The tendency towards pelvic lymph node involvement was reflected in Kilciksiz et al. While skin metastasis was reported in Baba et al.

The management of metastatic lymphadenopathy depends on various factors such as the presenting complaints, Eastern Cooperative Oncology Group (ECOG) Performance Status, the presence of other metastatic sites and hormone status. Here we managed it by excision of inguinal lymph node, palliative radiotherapy followed by palliative chemotherapy. An attempt at management was reported by three authors. Excision of inguinal lymph node followed by 40 Gy radiotherapy, combination chemotherapy (cyclophosphamide, adriamycin and 5-fluorouracil) and tablet tamoxifen was the approach by Baba et al. While Kilciksiz et al treated with palliative radiotherapy to a dose of 50 Gy to the inguinal region followed by taxane-based chemotherapy and hormone therapy (tablet tamoxifen).

It is assumed that stage, histopathology and hormone status of the primary disease are important factors that can influence the development of inguinal metastasis. In our report, at the time of diagnosis of breast cancer, the stage was IIIA, the histology was invasive ductal carcinoma, and the hormone receptors were negative. Except for Kilciksiz et al (stage IIA), all cases were of stage III. All cases were hormone receptor-negative contrary to the case reported by Kimoto et al. It was also noted that the immunohistochemistry from the inguinal lymph node was the same as that of the primary breast lesion. A similar finding was reported by Kilciksiz et al.

The survival of this patient from the detection of inguinal metastasis was 4 months only. While Baba et al reported survival of 42 months, Kilciksiz et al 7 months and Goyal et al 24 months. The other cases were retrospective or lost to follow-up.

The exact pathway of inguinal lymph node spread from a breast primary is not known. It may be through the subdermal lymphatics of the skin or retrograde pathway through submuscular fascia.^{13 14} The other possible reason could be an alteration of the physiological lymphatic channel through interventions such as breast surgery, radiotherapy and abdominal surgery.^{12 14 15} The presence of ectopic breast tissue in the vulva may also be an aetiology of inguinal metastasis.^{16 17}

Patient’s perspective.

My wife was treated for breast cancer. After some months of treatment completion, she developed pain and swelling in the groin. My doctor informed me that the breast cancer had come again and now it is stage 4. Then radiation was given to the swelling in the groin. The pain decreased and she was able to walk around for a brief period.

Learning points.

• Metastasis to inguinal lymph nodes from breast cancer is an extremely rare finding and has an aggressive clinical course.

• This could be associated with metastases to other sites too and thus a thorough clinical examination on presentation should be the dictum.

• Biopsy from the inguinal lymph node establishes the diagnosis and a positron emission tomography–CT scan is often helpful.

• Hormone receptor-negative breast cancer could be a risk factor.

• The intention of treatment will be palliative and should be aimed at amelioration of local symptoms.

Ethics statements

Patient consent for publication

Consent obtained from next of kin.