PRESENTATION OF CASE: We present the case of a female patient with a history of invasive lobular breast carcinoma who had undergone mastectomy and axillary dissection, followed by chemoradiotherapy. Over the next nine years, she developed ovarian and bone metastases for which appropriate treatment was provided. A right iliac fossa mass was discovered during routine clinic review, though she remained asymptomatic. Computed tomography scan showed ileocecal intussusception. Histopathological examination of the right hemicolectomy specimen following emergency surgery confirmed metastatic invasive lobular carcinoma to the GI tract.

DISCUSSION: GI tract metastasis may present 30 years after the primary breast cancer. Up to 20% of patients may be asymptomatic as shown by Montagna et al. When present, symptoms are commonly non-specific and vague. Histological diagnosis is challenging. GI metastasis typically appears as intramural infiltration of the bowel wall by small cells arranged in cords.

MATERIALS & METHODS: Data were obtained retrospectively from all patients who underwent both CT examinations - brain (frontal bone), thorax (T7), abdomen (L3), spine (T7 & L3) or pelvis (left hip) - and DXA between 2014 and 2018 in our centre. To ensure comparability, the period between CT and DXA studies must not exceed one year. Correlations between HU values and t-scores were calculated using Pearson's correlation. Receiver operating characteristic (ROC) curves were generated, and the area under the curve (AUC) was used to determine threshold HU values for predicting osteoporosis.

RESULTS: The inclusion criteria were met by 1043 CT examinations (136 head, 537 thorax, 159 lumbar and 151 left hip). The left hip consistently provided the most robust correlations (r = 0.664-0.708, p  0.05.