Adenoid cystic carcinoma of the breast - Discordant size on imaging and pathology: A case report and review of literature

Abstract

Introduction Adenoid cystic carcinoma (ACC) is an uncommon tumour of the breast. It is known for its rare lymph node involvement and distant metastasis. A triple-negative breast cancer that has a favorable prognosis compared to other triple negative ductal carcinomas, it accounts for approximately 0.1–1% of all breast cancers. Presentation of case We report a case of a 69-year-old female with a palpable left breast mass who underwent multiple imaging modalities with significant size variance between the studies. Breast conserving therapy (BCT) was performed with axillary sentinel lymph node biopsy (SLNB) followed by radiation therapy (RT). Pathological examination confirmed the tumour as ACC. Discussion ACC, known as an persistent if low-grade malignant tumour of salivary gland, is considered to have low-malignant potential in the breast. It is a very rare subtype and from this scant data, there is minimal mention about size discrepancy between imaging modalities such as ultrasound and MRI. No consistent MRI features have been demonstrated, with the exception of T2 hyperintensity in larger lesions and T2 iso-intensity in smaller lesions. Ultrasound demonstrates primarily a hypoechoic or heterogenous mass with minimum vascularity, consistent with our radiographic findings. Conclusion ACC is a rare entity in breast cancer pathology. Its size can be highly variable as measured by various radiographic modalities, and final Pathology from the surgical specimen is, as always, required for an accurate tumoral diameter. With that caveat, careful utilization of pre-operative imaging modalities is critical in pre-surgical planning to choose the appropriate surgery.

Breast adenoid cystic carcinoma arising in microglandular adenosis: A case report and review of literature

“…It also appears as an architectural distortion or asymmetry[ 22 - 26 ]. In the US examination, it shows an irregular shape, circumscribed or ill-defined margins, and iso-, hypo- or complex echogenicity[ 22 , 23 , 25 , 27 , 28 ]. In MR images, it shows circumscribed round mass with intermediate high T2 SI and persistent enhancing curve[ 23 ], increased T2 SI with variable kinetic curves[ 22 ], spicules and early phase enhancement[ 28 ], and mixed cystic and solid mass with irregular shape and margin, and rapid and heterogeneous enhancement[ 25 ].…”

The Utility of MYB Immunohistochemistry (IHC) in Fine Needle Aspiration (FNA) Diagnosis of Adenoid Cystic Carcinoma (AdCC)

“…Adenoid cystic carcinoma (AdCC) is an aggressive malignancy, accounting for approximately 5% of all neoplasm of the head and neck [1]. AdCC arise in various anatomic locations, including breast, tracheobronchial and lung, and morphologically resembles AdCC in salivary gland [2][3][4]. Although AdCC is characterized by slow growth, the longterm survival is determined by local recurrence rate despite treatment, tendency for perineural invasion, and distant metastasis [1].…”

“…Main histological patterns of AdCC include cribriform, tubular and solid [1][2][3][4]. The more common cribriform and tubular variants typically show abundant extracellular matrix arranged in globules with well-defined borders partially surrounded by basaloid tumor cells [5][6][7], which is reflected as characteristic cytology features of scattered balls of mucopolysaccharide matrix material surrounded by cohesive cellular clusters [6,7].…”

Adenoid Cystic Carcinoma (ACC) of the Breast: Unusual Breast Pathology in Young Women

“…Nowadays, diagnosis is based on the anatomopathological study of samples obtained by fine needle puncture. It presents a very characteristic histology [4].…”

“…There is also no consensus on which imaging technique is best when locating the lesion and planning surgical treatment. There have been discordant results regarding the size of the lesion between MRI and ultrasound or mammography [4]; this makes a careful radiological study by trained personnel necessary.…”