Apocrine carcinoma vs. apocrine metaplasia with atypia of the breast. Use of aspiration biopsy cytology

Cytological diagnostic clues in poorly differentiated squamous cell carcinomas of the breast: Streaming arrangement, necrotic background, nucleolar enlargement and cannibalism of cancer cells

OBJECTIVE

Squamous cell carcinoma (SCC) is a rare histological type of breast cancer. The cytological diagnosis of non-keratinising, poorly differentiated SCC is often difficult, and distinguishing it from invasive ductal carcinoma or apocrine carcinoma (AC) is especially challenging. We aimed to define the diagnostic cytological features of poorly differentiated SCC of the breast.

METHODS

We studied the cytological findings of poorly differentiated SCC (n=10) and compared them to those of IDC (n=15) and AC (n=14). The following six cytological features were evaluated: streaming arrangement, nucleolar enlargement, dense nuclei, cannibalism, atypical keratinocytes and necrotic background.

RESULTS

SCC exhibited significantly higher frequencies of streaming arrangement (70% vs 6.7%, P=.002), nucleolar enlargement (80% vs 27%, P=.02), and necrotic background (80% vs 36%, P=.002) than invasive ductal carcinoma. The detection of two or three of these features yielded a higher sensitivity (80%) and specificity (93%) for the diagnosis of SCC. Streaming arrangement (70% vs 0%, P<.001), cannibalism (60% vs 0%, P=.002), and a necrotic background (80% vs 36%, P=.047) were all significantly more frequent in SCC than in AC. When distinguishing SCC from AC, the presence of two or three of these features yielded a high sensitivity (80%) and specificity (100%).

CONCLUSIONS

Cytological features such as a streaming arrangement, a necrotic background, nucleolar enlargement and cannibalism are useful indicators for the diagnosis of SCC of the breast. As such, greater attention should be paid to these morphological features in daily clinical practice.

Encapsulated apocrine papillary carcinoma of the breast: case report with clinicopathologic and immunohistochemical study

We describe a case of encapsulated papillary carcinoma (EPC), apocrine variant in a 50-year-old woman. The patient presented a cystic lesion in her right breast, measuring 8 cm in diameter, containing three solid papillary nodules. A fine-needle aspiration showed isolated apocrine cells containing round nuclei, irregular nuclear membranes, fine chromatin, and prominent macronucleoli. The lesion was excised and showed a pure papillary apocrine carcinoma, which stained diffusely with GCDFP-15 and androgen receptors. The lesion was totally devoid of myoepithelial cells (smooth muscle actyn, p63, calponin, and collagen IV stains were negative). With MIB1 the proliferative activity was 10%. To the best of our knowledge, this is the first report of EPC apocrine variant with cytologic and immunohistochemical study. This lesion must be included in the list of apocrine lesions of the breast.

Granular cell tumor of the neurohypophysis: report of a case with intraoperative cytologic diagnosis

Cytological techniques including touch and smear preparations are very useful diagnostic modality in the evaluation of central nervous system (CNS) lesions and, in many instances, may be effectively used as the sole modality of tissue preparation for intraoperative consultation. Cytologic preparations offer many advantages over frozen sections for CNS specimens. These include selective examination of multiple areas from small biopsy specimens, superior preservation and details of cellular morphology, fewer artifacts, faster results, and improved cost-effectiveness. We describe the cytologic diagnosis of a granular cell tumor (GCT) of the neurohypophysis in a 33-year-old male who presented with headache and blurred vision. CT scan revealed an enlarged sella with a 2.15 x 2.0 cm pituitary lesion. Transsphenoidal resection of the mass was performed and submitted for intraoperative consultation. Smears and touch preparations were made on a portion of the mass that showed uniform polygonal cells with round to ovoid nuclei and abundant eosinophilic granular cytoplasm. An intraoperative cytological diagnosis of "favor GCT" was rendered. The histologic sections of the remaining material confirmed the diagnosis. Although GCT of the neurohypophysis is very rare, a specific intraoperative cytological diagnosis is possible. We report the clinical, cytological, and pathological findings of a GCT affecting the neurohypophysis.

Fine-needle aspiration cytology of apocrine adenosis of the breast: Report on three cases

Apocrine adenosis is a distinctive breast lesion, which can sometimes be misdiagnosed as malignant histologically. Although its histological characteristics have been well established, there are limited descriptions of its cytological features. We report fine-needle aspiration (FNA) cytology of three cases of apocrine adenosis. There were diverse cytological features between cases, and in two cases, FNA smears were highly cellular. Naked nuclei were present in all cases, and were numerous in one. Enlarged nucleoli and anisonucleosis were common. Apocrine metaplasia with nuclear atypia mimicking apocrine carcinoma was prominent in one case, whereas one case lacked definite apocrine features. Regardless of their various atypical FNA cytologies, the nuclei were consistently less hyperchromatic in all cases. Although FNA cytology of apocrine adenosis has the potential to be misinterpreted as malignant, the naked nuclei of background and less hyperchromatic nuclear features may be useful in distinguishing apocrine adenosis from carcinoma. Being familiar with these distinctive breast lesions is also important in decreasing false positives.

Fine-needle aspiration cytologic features of four special types of breast cancers: Mucinous, medullary, apocrine, and papillary

Recognition of special types of breast cancers by fine-needle aspiration (FNA) cytology may have prognostic implications but some difficulties still exist in the ability of cytopathologists to determine the tumor subtypes. Detailed cytomorphological features were studied in the four special and unusual types of breast cancer cases (8 cases of mucinous, 9 medullary, 9 apocrime, and 11 papillary) and compared between themselves and with those of 32 duct cell carcinomas, not otherwise specified (NOS). Papillary carcinomas were also compared with 10 benign papillary lesions. The significance of the differences was determined using Fishers' Exact Test of Probability. In mucinous carcinoma, the frequency of signet ring cells (62.5%), and background pools of mucin (87.5%) were significantly higher than those of duct cell carcinoma (NOS), medullary carcinoma, apocrine carcinoma, and papillary carcinoma (P = 0.0408 to < 0.0001). In medullary carcinomas, lymphomononuclear cell infiltration (100.0%) was observed in significantly higher number of cases than in papillary, mucinous, and apocrine types (P < 0.0001). Further, moderate to marked nuclear pleomorphism (100.0%) and nuclear irregularity (77.8%) was significantly higher than those of mucinous carcinoma and papillary carcinoma (P = 0.0294 to <0.0003). Abnormal apocrine cells and papillary formation, characterizing all the apocrine carcinomas and papillary carcinomas, respectively, were present in significantly lower number in other variants and in duct cell carcinoma (NOS) (P = 0.0002 to <0.0001). Glycogen vacuoles (63.6%) were observed in a significantly higher number of papillary carcinoma as compared to duct cell carcinoma (NOS), apocrine, and medullary carcinomas (P = 0.0047 to 0.0022). The significant parameters differentiating papillary carcinoma and benign papillary lesions were loose cohesive clusters (P = 0.001) and acinar formation by neoplastic cells (P = 0.0237). Histopathology reports available in 36 cases, confirmed the cytodiagnosis of carcinoma in all 35 cases and the benign lesion in one case. Cytological subtyping was confirmed in 13 of 16 special types of carcinomas and all the 15 duct cell carcinoma (NOS). Thus, special and unusual variants of duct cell carcinomas like mucinous, medullary, apocrine, and papillary have specific cytomorphological features, which differentiate them from one another and from duct cell carcinoma (NOS). However, differentiating features between papillary carcinoma and benign papillary lesions were very few in this study.

The enigmatic nature of apocrine breast lesions

Epithelial cells of fetal breast glandular structures, at the third trimester of pregnancy (28 weeks), produce GCDFP-15, in the absence of specific apocrine morphology. Apocrine epithelium of the breast may be a normal process of differentiation rather than a result of metaplasia, and it has been demonstrated that it is estrogen-receptor, progesterone-receptor and bcl-2 negative, but androgen-receptor (AR) positive. The significance of AR expression in apocrine epithelium is uncertain. Apocrine epithelium is seen in a wide spectrum of breast entities, ranging from benign lesions to invasive carcinoma. Breast cancer accounts 32% of all cancer cases among women and is the most common type of cancer in women. Little is known about breast carcinogenesis. Widely, it is accepted that breast cancer, like most other type of cancer, is being developed through the accumulation of genetic aberrations. Apocrine epithelium may reflect instability of the breast epithelium, creating an environment favouring further oncogenic alterations. In the last decade, several lines of evidence support the idea that some breast benign epithelial apocrine lesions are clonal lesions and may be considered as truly pre-malignant or precursors of breast carcinoma. Apocrine changes in many cases do not present any diagnostic difficulty; on the other hand, apocrine proliferations with cytologic atypia can be particularly difficult and challenging. The purpose of this study is to collect and highlight the areas of consensus in the literature as well as the controversial areas concerning the apocrine epithelium of the breast.