Low risk of invasive lobular carcinoma of the breast in carriers of BRCA1 (hereditary breast and ovarian cancer) and TP53 (Li-Fraumeni syndrome) germline mutations.

BACKGROUND: Invasive lobular carcinoma (ILC) of the breast has epidemiological, molecular and clinical specificities, and should likely be considered a unique entity. As for genetic susceptibility, CDH1 germline mutations predispose exclusively to ILC. Data are however scarce regarding ILC in women with BRCA1/2 (Hereditary Breast and Ovarian Cancer) and TP53 (Li-Fraumeni syndrome) germline mutations. METHODS: We included all breast cancers from female patients tested at our institute between 1992 and 2016 (n = 3469) for which pathology data were available. ILC proportion comparison according to mutational status was performed by a chi-squared test. The impact of susceptibility genes on ILC proportion was investigated by univariate logistic regression with wild-type patients as reference. RESULTS AND DISCUSSION: There were 265 (7.64%) ILC: 2/342 (0.58%) in BRCA1 patients, 24/238 (10%) in BRCA2 patients, 1/57 (1.75%) in TP53 patients and 238/2832 (8.4%) in non-carriers. The majority of breast cancers in all groups were invasive ductal and ductal in situ carcinomas. The difference in ILC proportion was highly significant (P < 0.001). Compared to wild-type patients, BRCA1 was associated with a lower ILC proportion (OR 0.064 [95% CI 0.016;0.259], P < 0.0001). BRCA2 OR was 1.222 [95%CI 0.785;1.902] (P = 0.374), TP53 OR was 0.195 [95%CI 0.027;1.412] (P = 0.105). ILC are therefore underrepresented in BRCA1 and TP53 mutation carriers. Formal significance (P = 0.05) was not reached for TP53, but statistical power was only 38%. Based on ILC incidence in the general population, we make the hypothesis that BRCA1 and TP53 do not predispose to ILC, as the few occurrences of ILC in mutation carriers could be attributed to chance and not to germline mutations. Our observations will be useful to clinical cancer geneticists managing patients with ILC, as a BRCA1 or TP53 mutation in these patients would be unlikely. Genetic counseling should be adapted accordingly.

Case report: Unusual breast cancer metastasis manifesting as a scalp lesion in a patient with invasive lobular carcinoma.

Breast cancer is the most prevalent cancer in women globally, often leading to distant metastasis in the lung, liver, or bones. Cutaneous metastasis represents an uncommon pattern in breast cancer, but when observed, it tends to manifest in the thorax and upper abdomen, primarily due to lymph node involvement. Therefore, occurrences of cutaneous metastasis on the scalp and extremities are infrequent. Moreover, invasive lobular carcinoma metastasizing to remote skin is rare among the breast cancer. This report presents a case of cutaneous metastasis of invasive lobular carcinoma to the scalp in a patient treated for breast cancer six years ago, with no signs of local recurrence or metastasis to other organs.

The Alveolar Variant of Lobular Carcinoma and Its Mimickers: A Case Series.

Invasive lobular carcinoma (ILC) is the most common special type of invasive breast cancer (IBC), accounting for 5-15% of IBCs. The distinct histomorphology of ILC reflects a special tumor biology, the hallmark of which is the lack of E-cadherin expression. However, the occasional presence of E-cadherin expression and the presence of IBC of no special type (IBC, NST)-like morphologies in ILC and vice versa make the diagnosis challenging.  We present two cases of the alveolar variant of ILC, a diagnostically challenging entity. The first case is an 81-year-old female with two discrete right breast masses at 1 o'clock and 9 o'clock positions.  The second case is a 61-year-old female with two discrete left breast masses located at 11 o'clock and 12 o'clock positions. Core needle biopsies and subsequent mastectomy were performed in both cases. On histology, three tumor foci were identified in the first case. The 1 o'clock focus showed IBC, NST, grade 3/3, ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). The 9 o'clock focus revealed ILC, classic and alveolar variants, grade 2/3, while a nearby third incidental focus was ILC, alveolar variant, both supported by lack of E-cadherin and ß-catenin immunostaining.  The second case showed ILC, alveolar variant, grade 1 with LCIS component in the 11 o'clock lesion on both biopsy and mastectomy specimens. The lesion at the 12 o'clock position was diagnosed as IBC, NST, grade 2 with high-grade DCIS and LCIS components.  It is challenging to distinguish the alveolar variant of ILC from IBC, NST, and in situ lesions because of the overlapping morphology and occasional E-cadherin expression. Altered adherence of lobular cells may also be due to loss of α-, ß-, and γ-catenins, and cytoplasmic re-localization of p120-catenin. Therefore, in ILC, the lack of ß-catenin can be used as an adjunct along with E-cadherin. Myoepithelial markers such as p63 and smooth muscle myosin heavy chain (SMMHC) can be used to distinguish the alveolar variant of ILC from LCIS.

A case study of pyloric stenosis caused by metastatic lobular carcinoma of breast.

Metastasis to the gastrointestinal tract is rare. A 59-year-old woman who had a history of an invasive lobular carcinoma of breast with clinical complete response visited our hospital and complained of an upper abdominal pain and distension. We performed an upper gastrointestinal endoscopy which showed only a gastric ulcer without any malignant findings. She experienced a recurrence of symptoms 2 months after this visit. An endoscopy revealed pyloric stenosis, which did not improve with balloon dilatation. We performed a gastro-jejunal and cecal-transverse colonic bypass surgery. Diffuse wall thickening of the antrum was verified during the surgery, and a biopsy sample was collected. The diagnosis of gastric metastasis from breast was confirmed since it showed the same immunohistochemistry pattern as the prior breast lesion. Pyloric stenosis has still been confirmed with an endoscopy, she has been alive with satisfactory oral food intake for >10 years.

Breast cancer with an initial gastrointestinal presentation: a case report and literature review.

The most common sites of breast cancer metastasis are the lymph nodes, lungs, bones, and liver. Gastrointestinal (GI) metastasis is relatively rare and often occurs within several years after a breast cancer diagnosis. Most patients experience abdominal pain, anorexia, bleeding, vomiting, and other digestive system symptoms, symptoms which are difficult to distinguish from primary gastric cancer. There is no characteristic change seen under a digestive tract endoscopy, and the difference in morphology under the pathological microscope from that of primary poorly differentiated gastric adenocarcinoma is so small that it can easily cause a misdiagnosis. This paper reports the case of 46-year-old female patient whose first symptom was GI discomfort. She was hospitalized for GI surgery with an unknown medical history, but, during the preoperative examination, multiple breast masses were found on both sides, which were proved by pathology to be invasive lobular cancer. According to the medical literature, bilateral breast cancer with gastric metastasis is very rare, and, so far, this is the first reported case. Despite it being a rare phenomenon, it is necessary to be aware of the possibility of metastatic lobular carcinoma in the diagnosis of poorly differentiated gastric adenocarcinoma by biopsy.

Case report and literature review: Metastatic lobular carcinoma of the breast an unusual presentation.

INTRODUCTION: Invasive lobular carcinoma is the second most common type of invasive breast carcinoma (between 5% and 15%). The incidence of invasive lobular carcinoma has been increasing while the incidence of invasive duct carcinoma has not changed in the last two decades. This increase is postulated to be secondary to an increased use of combined replacement hormonal therapy. Patients with invasive lobular carcinoma tend to be slightly older than those with non-lobular invasive carcinoma with a reported mean age of 57 years compared to 64 years. On mammography, architectural distortion is more common and microcalcifications less common with invasive lobular carcinoma than invasive ductal carcinoma. The incidence of extrahepatic gastrointestinal (GI) tract metastases observed in autopsy studies varies in the literature from 6% to 18% with the most commonly affected organ being the stomach, followed by colon and rectum. Gastric lesions seem to be slightly more frequent, compared to colorectal lesions (6-18% compared to 8-12%, respectively). PRESENTATION OF CASE: We present the case of a 70-year-old woman who was referred to our institution with a concurrent gastric and rectal cancer that on further evaluation was diagnosed as metastatic invasive lobular carcinoma of the breast. She has a stage IV clinical T3N1M1 left breast invasive lobular carcinoma (ER positive at 250, PR negative, HER-2/neu 1+ negative) with biopsy proven metastases to left axillary lymph nodes, gastric mucosa, peritoneum, rectal mass, and bone who presented with a partial large bowel obstruction. She is currently being treated with weekly intravenous paclitaxel, bevacizumab that was added after her third cycle, and she is also receiving monthly zoledronic acid. She is currently undergoing her 12-month of treatment and is tolerating it well. Discussion Breast cancer is the most common site-specific cancer in women and is the leading cause of death from cancer for women aged 20-59 years. It accounts for 26% of all newly diagnosed cancers in females and is responsible for 15% of the cancer-related deaths in women.(9) Breast cancer is one of the most common malignancies that metastasize to the GI tract, along with melanoma, ovarian and bladder cancer. CONCLUSION: We present one of the first reports of metastatic lobular breast cancer presenting as a synchronous rectal and gastric tumors. Metastatic lobular carcinoma of the breast is a rare entity with a wide range of clinical presentations. A high level of suspicion, repetition of endoscopic procedures, and a detailed pathological analysis is necessary for early diagnosis, which might help to avoid surgical treatment due to incorrect diagnosis. Patients with a history of breast cancer who present with new gastrointestinal lesions should have these lesions evaluated for evidence of metastasis through histopathologic evaluation and immunohistochemical analysis. Differentiating between a primary GI lesion and metastatic breast cancer will allow initiation of appropriate treatment and help prevent unnecessary operations.