Occult Breast Cancer

Today breast cancer is the most common cancer type in women, in both developed and developing countries. However, occult breast cancer is a highly rare type in all breast cancers. For the first time in history to know, Halsted defined the term “occult breast cancer” with 2 cases of his’ in the journal, Annals of Surgery. We have 2 similar cases who were 52 and 61-years-old patients and presented our clinic with left axillary swelling and pain. On physical examination and with imaging techniques there wasn’t any primary lesion found. Examination of lymph nodes’ biopsy material was compatible with breast cancer metastasis for both of the patients and they were diagnosed with occult breast cancer. They underwent a modified radical mastectomy surgery and axillary curettage. Histopathologic examination of the excised breast material revealed T1 invasive breast cancer.International Journal of Human and Health Sciences Vol. 02 No. 04 October’18. Page : 239-243


Introduction
Smith Surgery Papyrus is the first known document to cite breast cancer B.C. 3000-2500. About this cancer type, writer said "there is no treatment". Over the years with the developments about surgery, it is understood that this cancer type can be treated by resections. For the first time Radical Mastectomy surgery method has been used by Halsted in 1894. 1 Today breast cancer is the most common cancer type in women, in both developed and developing countries. It is thought that in 2013, 464.000 women have died because of the breast cancer worldwide. 2 Occult breast cancer, is a type of breast cancer which doesn't have any manifestations in physical exam or in any imaging study and shows itself only by axillary lymphadenopathy. For the first time, it is described by William Halsted with two presented cases in the journal Annals of Surgery, 1907. 3 Incidence of this rare cancer type is less than 0,34-0,88% amongst all breast cancers. [4][5][6][7] In this report, we present two of our cases who complain of left axillary swelling and pain. Case Report Case 1: Fifty two-year-old woman patient, presented to our hospital with left axillary swelling and pain. There was no pathologic finding on bilateral breast USG. There was also no other clinical findings on physical examination, rather than obvious lymphadenopathies. Malignant epithelial cell groups were seen in the image guided Fine Needle Aspiration Biopsy (FNAB) of axillary lymph nodes. In immunohistochemically staining, sample seemed to be estrogen receptor and progesterone receptor positive. These findings are judged to be compatible with breast carcinoma. In accordance to pathology results, we started to search for a primary focus in breast. Dynamic Bilateral Breast MRI showed that, both breast paranchymas are symmetrical and mildly heterogeneously dyed fittingly premenopausal age. There was no sign of any suspicious lesion or focally stained area. Any pathol- ogy of breast were not seen in diffusion MRI rather than axillary lymphadenopathies (Fig 1). FDG PET scan showed us hypermetabolic, metastatic lymph nodes; the largest ones measuring 20x12mm and 15x10mm in left axillary fossa.
Since imaging studies showed no sign of a primary focus, left axillary lymph node dissection was performed and material was analyzed pathologically and dyed ER, PR, Ki-67, mammaglobin and CA-125 positive; CERB-B2 negative. Nuclear expression with GATA-3 and membranous expression with E-Cadherin were seen. There were also metastasis of tumor in 5 of the 15 lymph nodes dissected. Immune profile of these lymph nodes taken was evaluated for papillary and micro papillary differentiating breast carcinoma (Fig 2). Acquired imaging results, clinical picture and having no result from searching for an extra mammary primary focal of tumor lead us to diagnosis of occult breast cancer. PET/CT scan didn't detect any lesion other than the one in the left axilla. Thereafter the patient underwent left simple mastectomy. In pathologic examination of the dissected material, there wasn't any occupant lesion. However, there was a 6mm radius area with irregular borders. Immunohistochemically evaluation of the dissected material showed estrogen receptor, progesterone receptor, E-cadherin with membranous positive and CERB-B2 negative. When it shows itself as axillary lymphadenopathy, all the other causes must be excluded. On the pathological examination of axillary lymph node biopsy material, especially being positive for estrogen receptor, progesterone receptor and CERB-B2 directs us to the breast cancer diagnose. 5,8,9 However it is highly important to study other tests to find the right diagnose since any focus can't be found with imaging techniques.
To treat the occult breast cancer, after reaching the diagnosis, surgery is recommended. Modified radical mastectomy, adjuvant chemotherapy and hormonotherapy give better outcomes by the means of survival. 10 Sometimes the tumor focus can't be found even in the mastectomy material. The two cases we report, presented our clinic with left axillary lymphadenopathy. On physical examination there wasn't any findings on breast. The hematological and biochemical tests we studied to exclude the other diagnosis were in normal range. Also the tumor markers were negative. For patient 1, it was recommended to make a biopsy owing to the screening the lymph nodes that can be interpreted as breast malignancy. Malign epithelial cell groups were identified by fine needle aspiration biopsy. Immunohistochemically characteristics were estrogen and progesterone positive and that finding was compatible with breast cancer metastasis. To find the primary focus and to make a breast protective surgery, mammography, ultrasonography, MRI and PET/CT were carried out, but no mass was found. Since the primary focus wasn't seen with screening, she was diagnosed as occult breast cancer and undergone a left mastectomy surgery. Patient 2 presented to our clinic with similar symptoms such as left axillary swelling and pain. We ran some initial tests which didn't give any clue about primary pathology.
So that we decided to evaluate the origin of the lymphadenopathy, tru-cut biopsy was performed and malignant epithelial cell groups with lymphoid rich base was found. It was compatible with breast cancer metastasis. On ultrasound screening a pathologic lymph node was seen in the left axillary area, which was 39x21mm, solid and without fatty hilus. In the next step, the primary focus wasn't found also with breast MRI but pathologic reactive axillary lymphadenopathy was seen. She was undergone an axillary lymph node dissection and there was metastasis on the 3 of 11 lymph nodes that dissected. Screening and other tests to find primary focus didn't give any clue. She was diagnosed with occult breast cancer and left simple mastectomy was applied.

Conclusion
Occult breast cancer is rare and doesn't reveal itself clinically or radiologically in breast. Due to axillary metastasis, it manifests as axillary lymphadenopathy. For all patients, who presented with lymphadenopathy, all benign and malignant causes must be thought, physical examination, blood work-up, tumor markers and biochemical evaluation should be done. Screening tests for whole body should also be performed. According to its findings, differential diagnosis must include also occult breast cancer.