[Technical recommendations and best practice guidelines for May-Grünwald-Giemsa staining: literature review and insights from the quality assurance]. / Recommandations techniques et règles de bonne pratique pour la coloration de May-Grünwald-Giemsa : revue de la littérature et apport de l'assurance qualité.

May-Grünwald-Giemsa (MGG) stain is a Romanowsky-type, polychromatic stain as those of Giemsa, Leishman and Wright. Apart being the reference method of haematology, it has become a routine stain of diagnostic cytopathology for the study of air-dried preparations (lymph node imprints, centrifuged body fluids and fine needle aspirations). In the context of their actions of promoting the principles of quality assurance in cytopathology, the French Association for Quality Assurance in Anatomic and Cytologic Pathology (AFAQAP) and the French Society of Clinical Cytology (SFCC) conducted a proficiency test on MGG stain in 2013. Results from the test, together with the review of literature data allow pre-analytical and analytical steps of MGG stain to be updated. Recommendations include rapid air-drying of cell preparations/imprints, fixation using either methanol or May-Grünwald alone for 3-10minutes, two-step staining: 50% May-Grünwald in buffer pH 6.8 v/v for 3-5minutes, followed by 10% buffered Giemsa solution for 10-30minutes, and running water for 1-3minutes. Quality evaluation must be performed on red blood cells (RBCs) and leukocytes, not on tumour cells. Under correct pH conditions, RBCs must appear pink-orange (acidophilic) or buff-coloured, neither green nor blue. Leukocyte cytoplasm must be almost transparent, with clearly delineated granules. However, staining may vary somewhat and testing is recommended for automated methods (slide stainers) which remain the standard for reproducibility. Though MGG stain remains the reference stain, Diff-Quik(®) stain can be used for the rapid evaluation of cell samples.

Intracystic papillary carcinoma of the breast: a diagnostic challenge with major clinical impact.

BACKGROUND: Intracystic papillary carcinoma (IPC) is a ductal carcinoma of papillary variety that develops in a cystic space surrounded by a fibrous capsule. It is a rare clinicopathological entity, the in situ or invasive character of which is difficult to establish, particularly on biopsy. The treatment is surgical and breast conservation depends on the tumor size. Lymph node exploration is still debated. The diagnosis of IPC is a challenge for the pathologist: the negativity of the basement membrane markers and of myoepithelial cells carries a risk of over-diagnosis on biopsy that can lead to over-treatment. CASE REPORT: To illustrate this risk, we report the case of a breast mass of 8 cm; its biopsy evoked invasive papillary carcinoma (no hormone receptors and overexpression of Human Epidermal Receptor-2 (HER-2) and for which neoadjuvant chemotherapy associated with trastuzumab was firstly proposed. RESULTS: The analysis of all anatomical radio-clinical data in a multidisciplinary context, however, allowed suspecting IPC, thus leading to first-line surgery (mastectomy with negative sentinel lymph nodes). With this diagnosis being confirmed on surgical specimen, no systemic treatment was then necessary. After 48 months, the patient is in complete remission.

[Breast cytopathology bestiary]. / Le monde animalier en cytopathologie mammaire.

Breast cytopathology of tubular and lobular carcinomas may be very difficult. Indeed, the classical morphological signs of malignancy are often scarce or absent; the identification of special patterns of cell clusters may therefore be very useful to reach a diagnosis. Following the review of many cases of cytological smears with histological confirmation, a series of peculiar cytological aspects (often mimicking little animals such as butterfly, eagle, dog, lizard, fish, rabbit...) were identified and found helpful to report here from a diagnostic point of view.