Male Breast Adenoid Cystic Carcinoma
The patient was a 41-year-old male who presented at the Department of Rehabilitation with symptoms of cervical back pain that had been occurring for 2 months. He was healthy, with an unremarkable medical history and a 20-pack per year smoking history. A cervical spine CT scan showed osteolytic changes with bony fragmentations in the C3, C5 and C6 transverse processes and vertebral bodies. These findings are suggestive of pathological fracture related to the presence of a tumor, such as metastatic carcinoma or multiple myeloma, rather than trauma (fig. ). To differentiate between metastatic bone lesions and the presence of a solid tumor, we examined the bone scan labeled with 99mTc, and the results showed only osteolytic bone lesions, with the exception of a small number of fractures. Therefore, we strongly suspected the presence of multiple myeloma (fig. ). We did a serum and urine protein electrophoresis evaluation and immunofixation, but there was no evidence of monoclonal gammopathy. In the bone marrow examination for excluding hematologic malignancies such as multiple myeloma and lymphoma, the findings showed that the hematopoietic cells were almost replaced by neoplastic cells with a glandular pattern. Neoplastic cells were stained with CK PAN (AE1/AE3) and were positive (fig. ).\nMetastatic carcinoma was suspected, but there were no abnormal findings in the esophagogastroduodenoscopy or colonoscopy. A PET-CT scan showed a disseminated hypermetabolic lesion (maxSUV = 7.4) in the axial skeleton, multiple, small-sized lung nodules and a multifocal hypermetabolic lung lesion (maxSUV = 2.6) as well as focal hypermetabolic lesions in the left axillary lymph nodes (maxSUV = 2.3) (fig. ). An ultrasound-guided core biopsy of the two 1.7-cm, low-echoic, pathological lymph nodes in the left level I axilla area was performed. The result of core biopsy was ACC (fig. ). Otorhinolaryngology and head and neck screening were performed to attempt to ascertain the location of the primary tumor in the salivary gland, as most ACC tumors in men are of salivary gland origin. However, this screening failed to identify specific lesions.\nTo identify the primary origin of the cancer, we reviewed the images and performed a whole-body physical examination. This revealed palpable and movable small nodular lesions in the periareolar area of the left breast, which had escaped interpretation on the PET-CT scan because the lesion was obscured (fig. ). There were clustered small nodules at the 1 o'clock and 2 o'clock locations around the left nipple upon physical examination. In a breast ultrasound, an irregularly-shaped solid lesion, 1.7 cm in size, was observed in the left subareolar area. The margin of the lesion was irregular and the internal area was relatively homogeneous and hypoechoic and was suggestive of a BI-RADS category 4C lesion. A core biopsy was performed and the pathology result was ACC, the same as that of the auxiliary lymph node biopsy (fig. ). Immunohistochemical staining was performed and the sample was negative for estrogen receptor (ER), progesterone receptor (PR) and c-erbB2, and positive for CK5/6 and P53. We finally diagnosed ACC of the breast with multiple lung and bone metastases and bone marrow involvement.\nThe authors submitted a waiver from their institutional review board (IRB) stating that this case report does not require IRB approval or oversight.