Granulocytic Sarcoma Presenting as a Palpable Breast Lump

Abstract

We report the case of a 45-year-old woman who palpated a voluminous painless lump in the superior outer quadrant of her left breast. Her past medical history revealed an acute myeloid leukemia (AML) treated and considered in remission 1 month prior to this discovery. Imaging work-up by mammogram, US, and MRI showed multiples masses suspect of malignancy in both breasts. US-guided needle biopsy was performed in the palpable mass and in one of the multiple lesions located in the right breast. Histologic findings were compatible with a granulocytic sarcoma in both breasts, which was considered as a relapse of the AML treated a few months earlier.

Myeloid sarcoma in the breast in a patient withacute myeloid leukemia: a case report

“…The levels of myeloperoxidase positive cell expression in MS tend to be between 66 and 83.6% 6 . The most common differential diagnoses include invasive lobular carcinoma, non-Hodgkin's lymphoma or even nonneoplastic conditions, such as inflammation and extramedullary hematopoiesis 8 . In the reported case, the diagnosis of invasive lobular carcinoma was the first to be considered.…”

An uncommon granulocytic sarcoma of the breast: a case report and literature review

“…The rarity of breast GS means that it is frequently misdiagnosed, most commonly as lymphoma, sarcoma, or breast carcinoma. The clinical findings of GS, including painless and painful palpable breast masses involving unilateral or bilateral breasts, are usually nonspecific, 9 thus increasing the risk of its clinical misdiagnosis as other primary breast cancers. The breast skin may sometimes be involved, and axillary lymph nodes may be observed, while nipple discharge and retraction are not common.…”

“…Histopathological examination together with immunohistochemical tests is the gold standard for a final diagnosis of GS, conventionally showing different degrees of myeloid differentiation. 9 However, the histopathological characteristics are inconsistent, potentially resulting in misdiagnosis or a missed diagnosis, especially in cases of isolated, low-differentiated GS. GS can easily be misdiagnosed as various other tumors, 7 and breast GS is often confused with infiltrating lobular carcinoma, primary breast sarcoma, Burkitt’s lymphoma, and diffuse large B-cell lymphoma.…”

“…Immunohistochemical tests, cytogenetic tests, and flow cytometry are useful methods for helping to reduce the misdiagnosis rate, and some molecular biomarkers of GS have been identified, including CD117, CD68, lysozyme, nucleophosmin, FLT3-internal tandem duplication, and the biochemical abnormality t(8; 21) inversion. 9 …”

“…The clinical features and imaging characteristics of breast GS are not specific, and it can therefore easily be misdiagnosed as other breast tumors, such as lymphoma, carcinoma, and benign tumors, especially primary tumors with no evidence of medullary disease. 8 , 9 Histopathological examination with immunohistochemical tests is currently the gold standard for diagnosis. Although some experts advocate the treatment of localized GS in relapsed acute promyelocytic leukemia with local radiation to the extramedullary disease site, systemic therapy is also usually required for relapsed disease.…”