Clinical and ultrasonographic characteristics of breast metastases from extramammary malignancies

Breast metastases from extramammary malignancies are uncommon, constituting about 2 per cent of all breast tumors. Breast metastasis may be confused with primary benign or malignant neoplasm of the breast. An accurate diagnosis of breast metastasis is important because the treatment and outcome of primary and secondary malignancies of the breast are completely different. The clinical features of 15 patients with breast metastases from extramammary malignancies, excluding lymphoma, between 1982 and 2001 were retrospectively reviewed. There were 2 male and 13 female patients, with ages ranging from 16 to 73 years (median, 48 years). Primary tumors in the 15 cases were 3 hepatocellular carcinomas, 2 gastric carcinomas, 2 malignant melanomas, 1 colon carcinoma, 1 lung adenocarcinoma, 1 ovarian carcinoma, 1 uterine leiomyosarcoma, 1 nasopharyngeal carcinoma, 1 esophageal squamous carcinoma, 1 embryonal rhabodomyosarcoma, and 1 cervical carcinoma. Bilateral breast involvement was observed in two patients. A solitary lesion was evident in 13 patients, with 6 in the right breast and 7 in the left. The interval between diagnosis of primary cancer and the discovery of breast metastasis ranged from 0 to 144 months (median, 12 months). The follow-up period of the primary tumor ranged from 7 months to 156 months (median, 17 months). Breast metastases were associated with disseminated metastatic disease in 14 of the 15 patients. Fourteen of the patients died within a year of breast metastasis diagnosis; median survival was 4 months. Breast metastases from extramammary malignancy are infrequent. Virtually any malignancy can metastasize to the breast. Breast metastasis usually indicates disseminated metastatic disease and a poor prognosis.     

The "gray zone" in fine needle aspiration cytology of the breast

Fine needle aspiration cytology (FNAC) is an essential procedure in the diagnosis of premalignant and malignant lesions of the breast. A "gray zone" exists between benign and malignant lesions in FNAC of breast; there an unequivocal diagnosis cannot be reached. Lesions in "gray zone" are categorized as "probably benign with atypia" (C3) and "probably malignant" (C4). Authors compared the cytology with histopathology and clinical follow-up of "gray zone" breast lesions, classified either as C3 or as C4 by FNAC. Amongst the total of 1679 FNACs, 85 (5%) were diagnosed as C3, whereas 101 (6%) were diagnosed as C4. Of the C3 cases, 48 patients underwent surgical biopsy. Histology proved malignancy in 21 (44%) cases, and was benign in 27 (56%) cases. Eighty-five open biopsies were performed out of the C4 cases. The histology was malignant in 76 (89%) cases, and benign in 9 (11%) cases. Lesions belong to "gray zone" should be taken into consideration in the FNAC of the breast and patients must be informed regarding this fact.     

Metastases of Cutaneous Squamous Cell Carcinoma Seem to be the Most Frequent Malignancies in the Parotid Gland: A Hospital-Based Study From a Salivary Gland Center

Malignant parotid tumors account for approximately 20% of all parotid lesions. In addition to the various primary parotid lesions there are secondary parotid malignancies, such as metastases or lymphomas. Data on histopathological distribution of all malignancies—including secondary parotid lesions—is limited. Recent evidence indicated a rising surgical incidence of secondary parotid malignancies. This study aims to review the distribution of malignancies in parotid resections from a salivary gland center. A retrospective review of prospectively collected data for all patients who had received parotidectomy between 2014 and 2019 was performed. Histopathological distribution was displayed separately for all parotid malignancies and for primary parotid malignancies. Further, patients` characteristics were compared between benign and malignant parotid lesions and between the two most common malignant parotid lesions. Out of 777 patients, 614 (78.9%) patients had a benign and 164 (21.1%) patients had a malignant parotid lesion. The most common parotid malignancy was metastatic cutaneous squamous cell carcinoma (cSCC) accounting for 35.4% of all parotid malignancies. 71.5% of all malignant lesions were secondary malignancies. Patients with metastatic cSCC were significantly older (p < 0.001) and significantly more likely to be male (p < 0.001) than patients with primary parotid malignancies. No significant difference was found when the lesion size of metastatic cSCC was compared to primary parotid malignancies (p = 0.216). The present study shows the high prevalence of secondary parotid malignancies in patients who had received parotidectomy. Furthermore, it confirms a rising surgical incidence of metastatic cSCC to the parotid gland in a series from a salivary gland center. At this time, parotid surgery for malignant lesions is more likely to be performed for metastases than for primary parotid malignancies.     

脾脏肿瘤35例的临床诊治体会

目的：探讨原发性脾肿瘤和脾转移癌（metastatic carcinoma of the spleen, MCS）的临床诊断与治疗。方法：对35例经外科治疗并经病理证实的脾肿瘤的临床资料进行回顾性分析。结果：增强CT检查对术前良恶性肿瘤鉴别准确率为85．7％，B超误诊率达20％。34例行手术探查，33例行脾切除或部分脾切除。术后病理显示，21例属原发性恶性肿瘤，其中以恶性淋巴瘤最常见，占80．9％；恶性淋巴瘤术后化疗，1年存活率为90．5％（19／21），3年存活率52．4％（11／21），1例术后9年仍存活。原发性血管内皮肉瘤和脾纤维肉瘤合并肝转移者各1例，手术介入治疗术后分别存活13个月和18个月。11例原发性良性肿瘤以血管瘤和淋巴管瘤为多见，分别占45．5％和27．3％，本组脾转移癌3例占8．5％（3／35），分别为胃癌脾转移、结肠癌脾转移和卵巢癌脾转移；2例于术后半年内死亡，1例术后14个月死亡。结论：原发性肿瘤以手术治疗为主．恶性淋巴瘤常需辅助性化疗。良性肿瘤术后无须特殊处理，瘤体小者行部分脾切除。早期发现、早期治疗才能提高脾脏原发性恶性淋巴肿瘤的生存率，对于MCS采取加强临床探查、结合影像学和病理检查可望提高检出率。     

Impact of inadequate fine-needle aspiration cytology on outcome of patients with palpable breast lesions

BACKGROUND: The purpose of the present study was to assess the impact of inadequate fine-needle aspiration cytology (FNAC) breast specimens on the outcome of patients with a palpable breast lesion. METHODS: A retrospective review was carried out of inadequate FNAC specimens from the Department of General Surgery, Singapore General Hospital in 1997. RESULTS: One hundred and thirty-eight (16.6%) of 831 FNAC specimens were reported inadequate, and these form the study group. Outcome analysis was divided into benign on excision biopsy (n = 38; 29.4%); benign on repeat FNAC or trucut biopsy (n = 6; 4.7%); benign on follow up (n = 46; 35.7%); malignant on histology (n = 11; 8.5%); and lost to follow up (n = 28; 21.7%). The 11 cases with breast cancer were further analysed. The mean time to treatment was 88.3 days for three patients whose tumours were not clinically suspicious of malignancy versus 20 days for six patients who were diagnosed with cancer clinically from the onset. One patient with cancer refused treatment and one absconded from treatment only to return 7 months later. CONCLUSION: Breast cancer was present in 8.5% of the inadequate FNAC specimens. When clinical suspicion of malignancy is high, an excision biopsy is advised in patients with inadequate FNAC specimens. If properly managed with triple tests and good clinical judgement, the inadequate FNAC specimens do not delay treatment in patients with breast cancer.     

Role of fine-needle aspiration cytology and needle-core biopsy in the diagnosis of lobular carcinoma of the breast

Fine-needle aspiration cytology (FNAC) plays a key role in the preoperative diagnosis of carcinoma of the breast but is less reliable in the diagnosis of infiltrating lobular carcinoma. The method of diagnosis was reviewed in 56 patients with lobular carcinoma who had attended screening and symptomatic clinics. In 29 patients FNAC results demonstrated malignant cells; 15 of these had palpable disease and the mean tumour size was 21 mm. In 27 patients FNAC failed to demonstrate malignant cells; 13 lesions were palpable and the mean tumour size was 23 mm. Ten patients were diagnosed by needle-core biopsy when FNAC was not diagnostic. FNAC may fail to diagnose even large lobular carcinoma and needle-core biopsy is strongly recommended in this situation.     

Radial scar and carcinoma of the breast: microscopic findings in 32 cases

We retrospectively reviewed the microscopic findings in 32 histologically confirmed radial scars in 31 women diagnosed in our unit during 1994–1998. The median age at diagnosis was 53 years (range 47–63 years). Thirty–one (97%) of 32 lesions presented as screen detected mammographic abnormalities (28 stellate lesions, 2 microcalcifications and only 1 architectural distortion). One lesion presented as a palpable breast mass. Stereotactic or ultrasound-guided fine needle aspiration cytology (FNAC) was performed in 28 cases. Cytological analysis of FNAs revealed malignant cells (C5) in 8 (29%) cases, highly suspicious cells (C4) in 3 (11%) cases, atypical benign cells (C3) in 7 (25%) cases and benign epithelial cells (C2) in 10 (35%) cases.All non-palpable lesions were surgically excised following wire localization. Histological examination of the breast specimens (mean WEIGHT = 16 g) demonstrated, in addition to a radial scar, 6 invasive carcinomas (2 infiltrating ductal, 2 tubular, 1 mixed ductal/lobular and 1 secretory carcinoma) and 4 ductal carcinoma in situ lesions (2 high grade, 1 high grade with micro-invasion and 1 low grade) arising in the radial scar. Of the remaining cases the radial scar was associated with atypical epithelial hyperplasia in 2 cases and regular epithelial hyperplasia in 17 cases (4 florid and 13 mild to moderate). In the 10 cases associated with malignancy, 9 had FNAC and was reported as malignant (C5) in 6 (67%) cases, highly suspicious (C4) in 2 (22%) cases and atypical (C3) in 1 (11%). False positive FNAC (C5) occurred in two patients, one of whom presented with pleomorphic microcalcifications suggestive of ductal carcinoma in situ. This patient was treated with a wire guided segmental mastectomy. All invasive tumours were less than 20 mm in size (T1) and of these 4 were grade I and 2 were grade II. Axillary dissection was performed in 4 patients none of whom had axillary node metastases.Our study demonstrates a significant incidence of malignancy associated with radial scars (31%) suggesting that radial scars may be premalignant lesions. This is supported by detecting various stages of mammary carcinogenesis (atypical epithelial hyperplasia, ductal carcinoma in situ, and early invasive malignancy) in these lesions. Fine needle aspiration cytology seems to be unreliable in the diagnosis of radial scar associated malignancy (67% sensitivity and 91% specificity). Stellate lesions, therefore, should be excised to obtain an histological diagnosis regardless of cytological findings. Further studies examining the biology of radial scars are required.     

Impact of Inadequate Fine‐needle Aspiration Cytology on outcome of Patients with Palpable Breast Lesions

Background : The purpose of the present study was to assess the impact of inadequate fine‐needle aspiration cytology (FNAC) breast specimens on the outcome of patients with a palpable breast lesion. Methods : A retrospective review was carried out of inadequate FNAC specimens from the Department of General Surgery, Singapore General Hospital in 1997. Results : One hundred and thirty‐eight (16.6%) of 831 FNAC specimens were reported inadequate, and these form the study group. Outcome analysis was divided into benign on excision biopsy (n = 38; 29.4%); benign on repeat FNAC or trucut biopsy (n = 6; 4.7%); benign on follow up (n = 46; 35.7%); malignant on histology (n = 11; 8.5%); and lost to follow up (n = 28; 21.7%). The 11 cases with breast cancer were further analysed. The mean time to treatment was 88.3 days for three patients whose tumours were not clinically suspicious of malignancy versus 20 days for six patients who were diagnosed with cancer clinically from the onset. One patient with cancer refused treatment and one absconded from treatment only to return 7 months later. Conclusion : Breast cancer was present in 8.5% of the inadequate FNAC specimens. When clinical suspicion of malignancy is high, an excision biopsy is advised in patients with inadequate FNAC specimens. If properly managed with triple tests and good clinical judgement, the inadequate FNAC specimens do not delay treatment in patients with breast cancer.     

Breast adenomyoepithelioma and adenomyoepithelioma with carcinoma (malignant adenomyoepithelioma) with associated breast malignancies: A case series emphasizing histologic,radiologic, and clinical correlation

The 2012 World Health Organization (WHO) classification of breast tumors distinguishes adenomyoepitheliomas (AMEs) as benign tumors composed of a biphasic proliferation of phenotypically variable myoepithelial cells around small epithelial lined spaces. Many AMEs have demonstrated benign behavior and are often cured with excision with negative margins, but some have exhibited malignant transformation of the myoepithelial cells, ductal epithelial cells, or both. When one of the components is histologically malignant, it is termed AME with carcinoma. Due to the rarity, the literature correlating imaging, histology, and clinical outcome is limited. A retrospective review was undertaken. A review of an institutional pathology database identified 14 cases with AME or malignant AME. Most AMEs had nonspecific imaging findings and were categorized as Bi-Rads 4. Histologic features of AME did not correlate with prior or concurrent breast malignancies or any radiographic features. Clinical follow up could be obtained for all but one case (mean follow up time = 75 months). 5 cases had no known treatment post-biopsy and 5 patients received mastectomy. No recurrences were noted. 3/13 cases of benign AME had associated breast malignancies including invasive ductal adenocarcinoma and ductal carcinoma in-situ. 1 case of malignant AME had a synchronous separate malignant phyllodes tumor. Given the unclear and unpredictable propensity for malignant transformation, conservative excision with negative margins currently seems appropriate.     

Diagnostic accuracy of vacuum-assisted biopsy device for image-detected breast lesions

Background : Non‐palpable breast lesions present diagnostic difficulties. Ultrasound‐guided fine‐needle aspiration cytology (FNAC) is a common method used to obtain a diagnosis, but FNAC is frequently inconclusive or insufficiently accurate. Recently a vacuum‐assisted biopsy device (Mammotome^®, Ethicon, Endo‐surgery, USA) has been introduced. The diagnostic accuracy of this biopsy device was assessed for lesions that were visible on ultrasound. Methods : Fifty ultrasound‐guided mammotome biopsies were performed. All were small breast lesions primarily detected by ultrasound. All received FNAC as initial assessment. Mammotome biopsy was performed whenever the breast lesion was considered indeterminate or if it was considered benign and there were associated risk factors such as a family history of breast cancer. Results : Of 50 mammotome biopsies 45 had benign histology. Three of 45 lesions were excised at the patients’ request and were confirmed to be benign. The remaining 42 patients received an ultrasound follow up at 6 months. The lesion size remained static in 39 patients. In three patients the lesion size increased and they were excised and histology was benign. For the four malignancies diagnosed with mammotome biopsy, three patients received definitive treatment and one patient defaulted. There was one failed mammotome biopsy in the present series. Conclusions : Mammotome biopsy is an acceptable diagnostic method for small breast lesions seen on ultrasound. It reduces the need for open biopsy without compromising diagnostic accuracy.     

Immunohistochemical diagnosis of a case of metastatic prostate cancer to breast

Bilateral breast mass was found in a 71-year-old male who had been placed on estrogen therapy for stage D2 prostatic adenocarcinoma. Microscopically the mass contained adenocarcinoma morphologically similar to that of the prostate, but the differential diagnosis was impossible between metastatic prostatic carcinoma and primary breast carcinoma. Formalin-paraffin sections of both tumors were stained positively by PSA (prostatic specific antigen) and PAP (prostatic acid phosphatase) using B-SA (biotin-streptavidin) system technique and prostatic origin of the breast mass was confirmed. Prostatic origin for metastatic carcinoma in the breast is are with only 30 reported cases in the literature including 5 Japanese cases. In most of them the diagnosis of the breast lesion as prostatic carcinoma has been made on morphologic and clinical grounds only. Accurate diagnosis is important for the prognosis of the patient, and immunohistochemical method is useful for he diagnosis of breast carcinoma metastasized from prostatic origin.     

The role of fine-needle aspiration cytology in children with persistent or suspicious lymphadenopathy

PURPOSE: The aim of this study was (1) To determine the value of fine-needle aspiration cytology (FNAC) in children with persistent or suspicious peripheral lymphadenopathy and (2) to analyze whether a history of previous malignancy influenced the accuracy of FNAC. METHODS: A retrospective study in an Academic Children's Hospital of 73 FNACs of peripheral lymph nodes in 64 patients (35 boys and 29 girls; median age, 9 years; range, 15 months to 20 years) was performed between 1992 and 1997. Eleven patients were excluded because aspirated material appeared inadequate. Outcome was compared with results of subsequent surgical biopsies, clinical follow-up, or both. Patients were divided into group A "de novo" lymphadenopathy (n = 39) and group B lymphadenopathy and a history of previous malignancy (n = 23). RESULTS: Group A: FNAC showed a benign diagnosis in 25 cases, a malignancy in 13, and was inconclusive in 1. Outcome was false-negative in 2 and false-positive in 1. Sensitivity and specificity were 86% and 96%, respectively. FNAC helped avoid additional surgical procedures in 27 cases (61%). However, if FNAC showed malignant lymphoma, open biopsy was inevitable (8 of 13) to establish proper classification. Group B: FNAC showed a benign diagnosis in 10 cases and a malignancy in 13. Outcome was false-negative in 1, and false-positive in 1. Sensitivity and specificity were 92% and 90%, respectively. FNAC helped avoid additional surgical diagnostic procedures in 25 cases (86%). CONCLUSIONS: (1) Fine-needle aspiration cytology is a rapid, simple and accurate diagnostic procedure to differentiate between benign and malignant peripheral lymphadenopathy in children. FNAC can avoid open biopsy in at least 60% of cases. (2) A history of previous malignant disease does not influence the accuracy of the test.     

Oral complaints caused from metastases to the mandible and maxilla

Jaw bone disorders causing oral complaints are common in primary care settings. Most of these conditions are of a chronic and benign nature. However they also may be the symptoms of a primary or secondary malignant process in the bone. The most common malignant bone tumor is metastatic carcinoma, and tumors arising in the breast, prostate, thyroid, lung and kidney have a special propensity to spread to bone. Yet metastases to the bones are rare; less than one per cent of all neoplasms metastases to the maxillofacial area. We describe four cases of metastatic tumours to the jaws. Two cases originated from the thyroid gland while the rest were from the oesophagus and the liver respectively. Three lesions occurred in the mandible and one in the maxilla. Patients presented with oral discomforts disregarding the primary tumor. Physicians who frequently advise patients with oral complaints should keep in mind that whereas these symptoms are mostly of a chronic and benign nature, metastases from a malignant tumor must be included in the differential diagnosis.     

'Tactile sensation': a new clinical sign during fine needle aspiration of breast lumps.

The tactile sensation (TS) felt during fine needle aspiration (FNA) of symptomatic breast abnormalities was recorded prospectively in 169 patients. TS was classified as malignant (if ''gritty''), or benign (if ''rubbery'', ''soft'' or ''fibrous''). This assessment was compared with fine needle aspiration cytology (FNAC) and the final diagnosis, to evaluate the clinical utility of TS. A ''gritty'' TS was recorded in 55/59 cancers and 22/110 benign lesions (sensitivity 93.2%, specificity 80%). Comparison of TS and FNAC in 69 patients with definitive histopathology revealed complementary results (TS, sensitivity 88.9%, specificity 48.5%; FNAC, sensitivity 55.6%, specificity 100%). Combining the sensitivity of TS with that of FNAC increased the overall sensitivity to 97.2%. Recording TS during FNA of symptomatic breast lumps enhances diagnosis, and alerts the clinician to the possibility of an underlying carcinoma when FNAC fails to confirm malignancy.     

Pathology of liver tumours

The liver is an important site for both primary and metastatic tumours. In non-cirrhotic patients, the commonest hepatic presentation of malignant disease is metastasis from other sites, most commonly colon, lung, stomach, pancreas and breast. In patients with cirrhosis, hepatocellular carcinoma is the most likely cause of hepatic malignancy, and is a major cause of cancer death worldwide. The malignant cells of hepatocellular carcinoma show differentiation resembling hepatocytes. There is a strong link with chronic viral hepatitis and cirrhosis of any cause, although an unusual slow growing variant of hepatocellular carcinoma called fibrolamellar carcinoma does not show these associations. Cholangiocarcinoma is adenocarcinoma arising in a bile duct, and is usually of unknown cause although some cases are linked with chronic biliary inflammation or infection. Intrahepatic cholangiocarcinoma is increasingly often diagnosed, although definitive diagnosis requires clinical exclusion of a metastasis from elsewhere. There is a variety of benign liver tumours, often manifesting incidentally during investigations. Some have a risk of malignant progression (dysplastic nodules in cirrhotic liver, some hepatocellular adenomas), while others are notable mainly for mimicking more serious disease than for great intrinsic significance.     

Lymphadenopathy as a primary presenting sign: a clinicopathological study of 228 cases

A total of 228 cases of lymphadenopathy as a primary presenting sign are reported. Tissue diagnoses were divided into: metastatic carcinoma (41 per cent), lymphoma (19 per cent), a specific non-neoplastic condition (10 per cent) and non-specific hyperplasia and inflammation (30 per cent); thus the overall yield of positive tissue diagnosis was 70 per cent. Just 5 primary sites: breast, lung, gastrointestinal and genito-urinary tracts and skin (mainly melanomas) accounted for all but one case. Hodgkin's and non-Hodgkin's lymphomas were evenly distributed. In those with generalized malignant lymphadenopathy a surprisingly even proportion of 1 to 1.5 was found between carcinoma and lymphoma. In those with localized malignant disease metastatic carcinoma predominated. The overall incidence of primary lymphadenopathy in increased with age, due to an increase in malignancy. Less than half of patients with carcinomatous lymphadenopathy had symptoms and these tended to be organ specific, whereas three-quarters of patients with lymphoma had symptoms which were usually non-specific. A haematological screen, liver function tests and chest X-ray were frequently abnormal but were not diagnostic.     

Pathology of liver tumours

The liver is an important site for both primary and metastatic tumours. Hepatocellular carcinoma is a major cause of cancer death worldwide, and in patients with cirrhosis is the most likely cause of hepatic malignancy. In non-cirrhotic patients, the commonest hepatic presentation of malignant disease is metastasis from other sites, most commonly colon, lung, stomach, pancreas and breast. In hepatocellular carcinoma, the malignant cells show differentiation resembling hepatocytes. There is a strong link with chronic viral hepatitis and cirrhosis of any cause, although an unusual slow-growing variant of hepatocellular carcinoma called fibrolamellar carcinoma does not show these associations. Cholangiocarcinoma is adenocarcinoma arising in a bile duct, and is usually of unknown cause although some cases are linked with chronic biliary inflammation or infection. Intrahepatic cholangiocarcinoma is increasingly often diagnosed, although definitive diagnosis requires clinical exclusion of a metastasis from elsewhere. There is a variety of benign liver tumours, often manifesting incidentally during investigations. Some have a risk of malignant progression (dysplastic nodules in cirrhotic liver, some hepatocellular adenomas), while others are notable mainly for mimicking more serious disease than for great intrinsic significance.     

Carcinoma of prostate metastatic to breast

Clinically diagnosed breast metastasis from prostatic carcinoma is rare. Primary breast carcinoma in patients with prostatic primary is also uncommon. Four patients who presented with breast malignancies in the course of their prostatic carcinoma are described. All but one of them had diffuse metastatic disease. Three of them were on estrogens at the time breast malignancy was diagnosed. Difficulties always arise in differentiating primary lesions from metastasis clinically and histopathologically. The development of histochemical methods for acid phosphatase, and the newest indirect immunofluorescent antibody technique, used in one of our patients, helped in making the differentiation between primary lesion and metastatic disease. Diagnosis of prostatic carcinoma metastatic to breast carries a poor prognosis, and may be an indication for aggressive therapy.     

Primary breast lymphoma: case report and review of literature

Primary non-Hodgkin's lymphoma of the breast is a rare entity representing 0.04-0.5% of all malignant female breast tumors, less than 1% of all patients with non-Hodgkin lymphoma and approximately 1.7-2.2% of all patients with extranodal non-Hodgkin lymphomas. A 75 years old patient presented with masses in the lateral part of the left breast for 6 weeks. Ultrasound detected 3 masses suggesting fibroadenomas while mammography set the suspicion of breast multicentric carcinoma. Fine needle aspiration cytology of one mass showed low grade lymphoma subsequently confirmed with histopathology which diagnosed extranodal non-Hodgkin lymphoma MALT type CD 20+/CD 79a+/CD 3-/Bcl 2- and index of proliferation Ki 67=30% (stage IE). Primary non-Hodgkin lymphomas of the breast, though rare, should be considered in the differential diagnosis of breast malignancies. At present, a standard treatment doesn't exist yet; low grade lymphomas should be managed with excision biopsy and/or local radiation therapy, while high grade lymphomas should be managed with chemotherapy in association with radiation therapy.     

Stratified diagnostic approach to fine needle aspiration of the breast.

The clinical value of fine needle aspiration (FNA) of the breast is enhanced by incorporating into the cytologic diagnosis explicit comments on the level of diagnostic certainty. This stratification of diagnostic certainty is based predominantly on the cytologic features but occasionally also takes into consideration the clinical situation. Strong clinical and mammographic suspicion of mammary carcinoma associated with FNA, diagnostic of typical, intermediate to high-grade mammary carcinoma, warrants proceeding to definitive therapy without further diagnostic studies. False-positive results are virtually eliminated by placing cases with any uncertainty into a "probable" category, which does not support definitive therapy. In addition, oversimplified "benign versus malignant" approaches to FNA diagnoses ignore the heterogeneity of breast masses, with in situ and low-grade carcinomas warranting special clinical management and usually being placed in the "probable" category. Thus, malignant diagnoses are stratified into "definite" and "probable," with only the former supporting definitive therapy. Within our recent series of 1,005 FNAs of the breast, we were able to confirm the diagnosis in all 62 patients with a "definite" carcinoma diagnosis, and only 3 of 25 "probable" cancer diagnoses were benign at tissue biopsy. Thus, false-positive results were successfully avoided in the "definite" category. Furthermore, a much greater incidence of unusual and good prognosis tumor types were identified by the "probable" category. If the clinical setting is relatively suspicious only, a definitive diagnosis of cancer by FNA is rare and not necessary because the clinical question to be addressed is only whether to biopsy. This approach to FNA diagnosis, unlike the oversimplified "benign versus malignant" scheme, provides an approach that is more likely to result in optimal therapy for breast neoplasms, with low-grade or in situ carcinomas requiring special clinical management since these types of cancers are found predominantly in the "probably malignant" category. It also provides additional security against false-positive diagnoses by incorporating clinical level of certainty statements into FNA diagnostic categories, which more closely reflect the diversity and inherent complexity in the appropriate diagnosis and therapy of mammary carcinomas.