Liver metastasis of breast carcinoma: An unusual presentation and growth pattern.

Breast carcinoma is one of the tumors that frequently metastasize to the liver. Extramedullary hematopoiesis (EMH) usually occurs due to insufficient medullary hematopoiesis. In this case report, we present a female patient with sinusoidal breast carcinoma metastasis and extramedullary hematopoiesis in liver biopsy. A 63-year-old female patient with history of breast carcinoma was admitted to our center with respiratory distress. Pleural effusion was detected and thoracentesis was planned. Treatment was given after detection of non-mycobacterial tuberculosis bacillus in the thoracentesis fluid. Antibiotherapy was terminated due to elevation of liver enzymes and bilirubin. The patient's clinical status was evaluated and treatment was re-initiated. The patient did not have any mass lesion in the liver. Tru-cut biopsy was performed to evaluate a possible tuberculosis involvement in the liver. The diagnosis of metastatic breast carcinoma located in the sinusoidal area and cholestatic liver with extramedullary hematopoiesis foci was given using the histomorphological, immunohistochemical and histochemical findings. Radiological evaluation has an important role in staging of malignancies. However, it should be kept in mind that hepatic metastases may present without formation of a mass lesion, and unexpected laboratory results of cases without abnormal radiological features should raise the suspicion of a metastasis. Such materials should be evaluated in detail by making multiple serial sections in the pathology laboratory. Rare metastatic tumor growth patterns not causing a mass lesion such as sinusoidal or portal pattern, should also be kept in mind.