Primary small cell (oat cell) carcinoma of the breast: report of a case and review of the literature

A case of primary small cell (oat cell) carcinoma of the breast in a 41-year-old woman is presented. The patient was alive and well without disease 16 months after modified radical mastectomy and subsequent chemotherapy. The tumor cells revealed morphologic similarity to oat cell carcinoma of the lung and immunohistochemical expression of neuroendocrine markers. In ultrastructural examination, the tumor cells had neurosecretory granules. Review of nine previously reported cases and this case of primary small cell carcinoma of the breast has revealed that this type of tumor shows prominent vascular invasion, frequent lymph node metastasis, infrequent expression of estrogen receptor, and also very poor prognosis. Immunohistochemical study for the c-kit proto-oncogene product, which has been reported to be a specific marker for pulmonary small cell carcinoma, demonstrated positive reactivity in approximately 80% of the tumor cells of this case, which is the first report according to our knowledge. The expression of c-kit might be some aid to the diagnosis of primary small cell carcinoma of the breast.     

Breast carcinoma with predominant neuroendocrine differentiation

Neuroendocrine differentiation can be identified in a subset of human breast carcinomas, either as scattered cells or as a predominant neuroendocrine component. We report a case of an invasive breast carcinoma largely composed of neuroendocrine cells. Eight years after a left mammary lumpectomy for a pT2N1MO SBR III invasive ductal carcinoma, a 67-years-old woman presented with a metastastic neuroendocrine sternal mass. To establish a relationship between mammary carcinoma and bone metastasis, histological slides of both the breast tumor and axillary lymph nodes were reviewed, and an immunohistochemical study was performed. They showed that: a) the mammary carcinoma was composed of a majority of small and large neuroendocrine cells synaptophysin +, NCAM+, chromogranin - (80%), associated with 2 other differentiated non endocrine components, one of metaplastic squamous carcinoma (10%) and the other of ductal carcinoma (10%); b) 4 axillary lymph nodes were involved by the ductal component which contained few NCAM + but synaptophysin - cells; c) Estrogen and progesterone receptors and HER2 were negative in the breast tumor and the metastatic nodes. We discuss the histogenesis of composite mammary carcinomas with neuroendocrine differentiation, the outcome of each component and the prognostic relevance of such a diagnosis.     

E-cadherin-negative primary small cell carcinoma of the breast. Report of a case and review of the literature

Primary small cell carcinoma of the breast is exceedingly rare, with fewer than 25 reported cases. The case presented herein is that of a 61-year-old woman with a 2.5-cm mass of the left breast. She underwent mastectomy with axillary node dissection. Histologic examination revealed sheets and nests of small, hyperchromatic, malignant cells with indistinct nucleoli and scant cytoplasm. High-grade solid and comedo ductal carcinoma in situ also was present. Two of 5 axillary lymph nodes contained metastatic disease. Immunohistochemical analysis demonstrated weak immunoreactivity for cytokeratin, neuron-specific enolase, and bcl-2. This histologic and immunohistochemical profile was consistent with that of a primary small cell carcinoma. Interestingly, this neoplasm lacked immunoreactivity for E-cadherin. E-cadherin expression has been documented in all 11 (100%) of 11 previously reported cases of primary small cell carcinoma of the breast, suggesting that this tumor is a form of ductal carcinoma. To our knowledge, this is the first reported case of E-cadherin-negative small cell carcinoma of the breast, which raises the question of a possible lobular histogenesis in some of these neoplasms.     

Spontaneous regression of breast cancer with axillary lymph node metastasis: a case report and review of literature

Spontaneous regression (SR) of cancer is a rare but well-documented biological phenomenon. However, the mechanism remains to be elucidated. We herein report a case of the SR of breast cancer at both the primary site and metastatic axillary lymph node with spontaneously-induced T cell-mediated immunological responses. A 52-year-old female with a lump in the left axilla was diagnosed to have a small breast carcinoma with a distinct axillary lymph node metastasis. During the preoperative systemic examination, she was diagnosed to have severe type 2 diabetes mellitus, was treated with insulin, and the hyperglycemia was normalized after one month. Surgery for left breast cancer was then performed. The postoperative histopathological examination revealed the SR of breast cancer at both the primary site and metastatic axillary lymph node. Immunohistochemical studies revealed that estrogen receptor positive, AE1/AE3-positive ductal carcinoma completely underwent necrosis associated with extensive infiltration of CD3-positive T cells in the tumor nodule in the lymph node. In addition, primary ductal carcinoma cells also underwent single cell necrosis with infiltration of T cells with lymph follicle-like organization of B cells in the mammary gland. The features were suggestive that the tumor eradication in the metastatic lymph node and regression of the primary ductal carcinoma could be due to host T cell response to the ductal carcinoma. As far as we know it is the first report that shows the spontaneous regression of breast cancer, probably due to the spontaneously-induced T cell response.     

Neuroendocrine breast carcinoma metastatic to renal cell carcinoma and ipsilateral adrenal gland

We report on a 60-year-old woman with neuroendocrine carcinoma of the left breast metastasizing to renal cell carcinoma (RCC) of the left kidney and to adrenal gland. A yellow, well-circumscribed tumor, 11 cm in largest diameter and limited to the kidney, was found. Histopathology revealed RCC with foci of neuroendocrine differentiation. Solid sheets of hyperchromatic epithelioid cells with high mitotic activity were found between typical clear cells of RCC. These cells were CAM5,2 and E-cadherin focally positive, synaptophysin and NSE weakly positive, CK19 moderately positive, and AE1-AE3 and EMA strongly positive. Chromogranin A, CD10, CK 14, CK 20, HER2 (score 1+), vimentin, and HMB45 were negative. The left adrenal gland contained multiple, separate foci of a tumor composed of neuroendocrine components. Because of the biphasic tumor in the kidney, extensive clinical examination and further analyses were recommended. Tumor in the left breast was revealed. Two months later, the patient underwent mastectomy with axillary lymph node dissection. The tumor was histologically and immunohistochemically similar to the neuroendocrine component within RCC. All axillary nodes were positive. To our knowledge, this is the first case of neuroendocrine breast carcinoma with metastasis to renal cell carcinoma and ipsilateral adrenal gland.     

Neuroendocrine differentiation in pure type mammary mucinous carcinoma is associated with favorable histologic and immunohistochemical parameters.

Mucinous carcinoma of the breast is a specific good prognostic type malignancy occurring in elderly patients. Neuroendocrine differentiation has long been described in mucinous carcinoma, but the significance of such finding is uncertain. We evaluated the neuroendocrine differentiation profiles of 38 cases of pure mucinous carcinoma and compared the clinicopathological differences between those with and those without neuroendocrine differentiation. The parameters assessed included patients' age, tumor size, nuclear grade, axillary lymph node status at time of diagnosis, percentage area of intratumoral mucin, and the expression of estrogen and progesterone receptors, cerbB2 oncoprotein, and three neuroendocrine markers, namely neurone-specific enolase, chromogranin, and synaptophysin by immunohistochemistry. Patients' outcome and follow-up period were also documented. Of the 38 cases of pure mucinous carcinoma, 28, 11 and six cases showed positive staining for 1, 2 and 3 of the neuroendocrine markers. For all the groups with variable neuroendocrine differentiation and compared to those without such differentiation, they all showed older patients' age, higher proportion of tumors with lower nuclear grade, lower incidence of axillary lymph node metastasis, a higher progesterone receptor, and lower cerbB2 oncoprotein expression. No difference was detected between tumor size, intratumoral mucinous area, and estrogen receptor status. In all, 37 patients did not have distant metastases or local recurrences at the end of follow-up period, while one patient with coexisting high-grade ductal carcinoma in situ at time of diagnosis died of breast carcinoma. Our findings suggest that the identification of neuroendocrine differentiation in pure mucinous carcinoma is associated with more favorable histologic and immunohistochemical parameters.     

Neuroendocrine carcinoma of the breast with Merkel cell carcinoma-like features

A case of neuroendocrine carcinoma of the breast with Merkel cell carcinoma-like features occurring In a 38-year-old female Is described. A 2.5 × 2.5 × 1.3 cm tumor in the upper-outer quadrant of the right breast was ill-defined, yellowish white and rubbery. Microscopically, the tumor was characterized by a diffuse proliferation of non-cohesive round cells. The tumor cells had round nuclei with finely dispersed chromatin and inconspicuous nucleoli. The cytoplasm was generally scant, pale to eosinophilic, and argyrophilic. There were scattered foci of small nests or intraductal proliferations. Immunohistochemically, many tumor cells showed positive reaction for CAM5.2, vimentin, chromogranin A, and synaptophysin. The tumor was also positive for neuron-specific enolase (NSE), Leu-7, calci-tonin, S-100 protein, and glial fibrillary acidic protein. Flow cytometric analysis showed that the tumor was DNA diploid. An axillary lymph node was positive for metastasis. The patient was well, without disease, for 6 years after mastectomy. It is suggested that the tumor might originate from ductal cells and show Merkel cell carcinoma-like neuroendocrine differentiation.     

Small cell (oat cell) carcinoma of the breast

A case of small cell (oat cell) carcinoma, which represents both the most dlstlnctlve and the least common type of mast carcinoma wtth neuroendocrine dlfterentiation and usually shows the most aggressive behavior, is described. Radlcal mastectomy was performed on a Wyearold female for a 10 cm tumor located in the outer part of the right breast with cutaneous ulceration Microscoplcally, the tumor predominantly consisted of a diffuse proliteration of small, round to ovoid cells with hyperchromatlc nuclei and ill-defined, scant cytoplasm that was reminiscent of oat cell carclnoma of the lung. There were foci of invasive ductal carcinoma and ductal carcinoma in situ . Small cell carcinoma areas constituted approximately 90% of the neoplasm. The patlent had axlllary lymph node metastasis. The small tumor cells were argyrophlllc and positive for CAM5.2, carclnoembryonic antigen, neuron-specific enolase, Leu-7, chromogranln A and synaptophysin. Flow cytometric analysis showed an aneuplold DNA content. The patient was alive and well without disease 4 years after surgery. Small cell carcinomas of the breast may exhibkt a spectrum of malignancy that is comparable to similar tumors at better known primary sites.     

Unusual metastases of papillary thyroid carcinoma: report of 2 cases

We present 2 cases of papillary thyroid carcinoma (PTC) with conventional morphology that metastasized to unusual sites. The first neoplasm was a PTC whose initial clinical manifestation was a large metastasis in the pancreas which mimicked a primary neoplasm. The mediastinal location of the thyroid gland was responsible for the delay in identification of the primary tumor. Eventually, the patient, a 72-year-old man, developed brain and vertebral metastases. The second case was that of a 58-year-old woman with a PTC with initial metastases in cervical lymph nodes; subsequently, the tumor spread to axillary lymph nodes and finally to the breast. Transformation to anaplastic spindle and giant cell carcinoma within the breast metastasis occurred 20 years after the primary thyroid tumor had been diagnosed and surgically treated. The metastatic anaplastic spindle and giant cell carcinoma contained rhabdoid inclusions further complicating identification. To the best of our knowledge, only 3 cases of PTC metastatic to the breast have been reported, none of them with anaplastic transformation. On the other hand, only 3 cases of PTC metastatic to the pancreas have been published, 2 of them of the tall cell variant, and in none of these cases were the first symptoms attributable to the metastasis. Brief comments about the differential diagnosis are included.     

Paracortical axillary sentinel lymph node ectopic breast tissue

Benign glandular inclusions in axillary lymph nodes are uncommon, and their presence in axillary sentinel lymph nodes is exceptionally rare. The possibility of over-staging due to misinterpretation of glandular inclusions as metastatic carcinoma is a concerning issue. We present a 54-year-old female with high grade ductal carcinoma in-situ undergoing simple mastectomy with sentinel lymph node biopsy. Permanent sections of the sentinel lymph node revealed scarce naked small glands without surrounding stroma scattered in the paracortex in the superficial level. Deeper levels showed glands spanning a much larger area (2 mm), with bland ducts and tubules separated by abundant stroma. The myoepithelial layer was visible and was immunohistochemically confirmed. A final diagnosis of benign ectopic breast tissue within an axillary sentinel lymph node was rendered. Previous studies described axillary sentinel lymph nodes with glandular inclusions separated by stroma or subcapsular in location. It has been suggested that paracortical location and absence of stroma are characteristics of metastasis. As demonstrated in our report, benign inclusions may be paracortical and lack surrounding stroma. We recommend that glandular inclusions should be a diagnostic consideration for cases in which paracortically located naked glands do not histologically resemble the corresponding primary tumor.     

Cytohistologic features of invasive micropapillary carcinoma in a young female

Invasive micropapillary carcinoma (IMPC) is a recently reported variant of breast carcinoma in women. There has been only a single report describing the cytologic features of IMPC in the literature. We report on the cytohistologic features of IMPC with diffuse involvement of two quadrants of the breast and axillary lymph node metastases in a 32-yr-old female. The cytologic appearance of IMPC was characterized by high cellularity, marked cell discohesion, and epithelial cells forming aggregates, morules, and angular and papillary clusters without fibrovascular cores and showing high nuclear/cytoplasmic ratio, irregular nuclear contours, and finely stippled chromatin. Occasional psammoma bodies were noted. Histologic examination showed a pure IMPC composed of clusters, morules, and aggregates of malignant epithelial cells surrounded by distinctly clear spaces separated by thin fibrovascular septa. The tumor involved both inner quadrants and axillary lymph nodes. A primary tumor elsewhere, particularly in the ovaries, was excluded. The patient has been disease-free 38 mo after the initial diagnosis.     

A metastatic renal carcinoid tumor presenting as breast mass: a diagnostic dilemma

We present clinicopathological and cytological findings of a well-defined breast mass in a patient with history of primary renal carcinoid tumor. Fine-needle aspiration (FNA) cytology showed monotonous tumor cells with plasmacytoid appearance arranged singly and in small clusters. Occasional tumor cells were arranged in acinar architecture resembling glandular differentiation. Tumor cells showed fine speckled chromatin. The unusual location for metastasis of this rare type of carcinoid tumor and overlapping cytological features with primary mammary carcinoma led to an erroneous preliminary cytological diagnosis of primary breast carcinoma with plasmacytoid features. Tumor cells in the corresponding cell block showed strong diffuse positivity for synapthophysin and pan-cytokeratin with weak focal positivity for chromogranin markers. These patterns of immunostaining were similar to the original renal carcinoid tumor. To the best of our knowledge, a few cases of carcinoid tumor metastatic to the breast have been reported in the literature and more than half of these cases were initially misdiagnosed as primary breast carcinoma causing unnecessary surgical treatment. This is a first reported case of metastatic renal carcinoid tumor into breast diagnosed with FNA biopsy. This report highlights the cytological features of well-differentiated neuroendocrine tumor (carcinoid tumor) and its potential diagnostic pitfalls.     

Secretory breast carcinoma in a man. A case report with rapid evolution unfavorable

Secretory carcinoma or juvenile carcinoma of the breast is a very rare tumor of male adults. Generally, it has a good prognosis after locoregional treatment. The authors report an observation of a secretory carcinoma occurring in a 20 year old man. The lesion presented as a voluminous tumor 12 cm in diameter with 3 positive lymph nodes; it was treated by mastectomy and axillary dissection. Tumor developed in a few months, with visceral metastasis and fatal issue. The cytological, histological and immuno-histochemical features necessary to the diagnosis are described. The rapid development of this case of secretory carcinoma is unusual. This leads the authors to propose the use of an additional treatment for adult secretory breast carcinoma with more than 3 positive lymph nodes.     

Diagnostic clues for differentiating Merkel cell carcinoma from lymphoma in fine-needle aspiration cytology

Nodal fine needle aspiration (FNA) is usually the first procedure in the work-up of malignancy of unknown primary. Merkel cell carcinoma (MCC) is an aggressive cutaneous cancer more common in Caucasians but rare among Asians. It is a diagnostic challenge in evaluating FNA from a metastatic MCC without the knowledge of a current or prior history of skin cancer. We report the case of a Taiwanese male with cervical and axillary masses. The diagnosis of the FNA from the axillary lymph node was lymphoproliferative lesion suspicious for lymphoma. The histopathological evaluation of nodal biopsy revealed a metastatic neuroendocrine carcinoma and the subsequent excision of the right palm tumor confirmed MCC. Retrospective review of the FNA and imprint cytology smears of the nodal biopsy showed nuclear molding, Indian filing and rare cytoplasmic pale bodies, but no lymphoglandular bodies. Cytologically metastatic MCC may mimic small round cell tumor including lymphoma, we consider these three cytological features as additional diagnostic clues for metastatic MCC. In this report, we present the cytologic and pathological features of this metastatic MCC and discuss the differential diagnosis of the cytologic mimickers.     

Synchronous metastases to the liver and pancreas from a primary neuroendocrine carcinoma of the breast diagnosed by fine-needle aspiration

Extrapulmonary neuroendocrine carcinoma is uncommon. Cases of primary neuroendocrine carcinoma of the breast have been reported, though rare. We report the case of a 53-year-old woman who underwent a mastectomy for breast carcinoma and presented three years later with synchronous masses in the head of the pancreas and liver. Fine-needle aspiration of both organs revealed a neuroendocrine carcinoma. The original breast tumor was reviewed and found to express neuroendocrine markers. A diagnosis of a primary neuroendocrine carcinoma of the breast was rendered.     

Poorly differentiated squamous cell carcinoma of the nipple: a unique case for marked exophytic growth, but little invasion with neuroendocrine differentiation

A 73-year-old woman showed marked exophytic growth of a tumor (25 × 23 × 14 mm) of the nipple over a period of 2 months. Histologically, numerous tumor nodules with no apparent keratinization were observed in the exophytic lesion. The tumor cells also showed little invasion to the dermis and no metastasis to the axillary lymph nodes (LN). The tumor cells were immunohistochemically positive for cytokeratins (CKs; AE1/AE3 and 34βE12), epithelial membrane antigen (EMA), and p53, but negative for Ber-EP4 and human papilloma virus (HPV). The MIB-1 index was 56%. Some tumor cells were also positive for some neuroendocrine markers, and showed some tonofilaments and neurosecretory granules in the cytoplasm under electron microscopy. We made the differential diagnosis of mammary ductal carcinoma, basal cell carcinoma (BCC), Paget’s disease, and neuroendocrine carcinoma including Merkel cell carcinoma. The final diagnosis was poorly differentiated squamous cell carcinoma (SCC) showing exophytic growth with neuroendocrine differentiation (ND) in the nipple. To our knowledge, although only five cases of Bowen’s disease have been reported in the nipple, such a unique SCC has not been reported previously.     

The spectrum of pathological diagnoses in non-sentinel axillary lymph node biopsy: A single institution's experience

Although axillary lymphadenopathy is a common clinical encounter, systemic evaluation of non-sentinel lymph node biopsy is sparse. We reviewed our institution's 15-year experience to delineate the spectrum of diagnoses in non-sentinel axillary lymph nodes. 1165 non-sentinel axillary lymph node biopsies were retrieved and the diagnosis and relevant clinical information was reviewed. This spectrum of diagnoses was further stratified by gender, age, and oncologic history. The spectrum of diagnoses included: breast carcinoma (27.6%), lymphoma (29.2%), melanoma (3.5%), other carcinoma (2.9%), sarcoma (0.4%), and benign changes (36.3%). The most common diagnoses in men were lymphoma (61.8%) and benign changes (23.6%); while in women they were benign change (41.2%), breast carcinoma (37.8%) and lymphoma (16.7%). Besides benign changes, lymphoma and breast carcinoma were most common in women younger and older than 30 years, respectively. In patients with a history of malignancy, the most common diagnoses were metastasis from the known tumor and benign change; while in patients with a negative oncologic history and female patients without a history of breast cancer, the diagnosis was generally either lymphoma or benign change. Anaplastic large cell lymphoma was rare but may be mistaken as metastatic carcinoma thus a high index of suspicion is warranted. Thus through retrospective review of a large cohort of non-sentinel axillary lymph node biopsies, we described the spectrum of pathological entities based on the gender, age, and clinical history, which could provide valuable information for further work-up of axillary lymph node biopsy.     

CD44 expression and axillary lymph node metastasis in infiltrating ductal carcinoma of the breast

Metastasising ability connotes one of the most important life-threatening properties of malignant neoplasms. Recent studies indicate that CD44 proteins, multifunctional cell adhesion molecules which contribute to "homing" of lymphocytes to lymph nodes as well as cell-cell and cell-matrix interactions, are potential markers of tumour progression. However, whether CD44 expression by human tumours contribute to increased metastatic risk remains controversial. In an attempt to clarify its role in breast cancer, we have investigated the correlation between CD44 expression by breast carcinoma and the presence of axillary lymph node metastases. CD44 expression was detected using a standard immunoperoxidase method on formalin-fixed, paraffin-embedded, primary infiltrating ductal breast carcinoma tissues taken from 60 female patients who underwent mastectomy with axillary node clearance. Tumours were graded according to the modified Bloom and Richardson criteria. 62% of patients had histologically-proven lymph node metastasis. 40% of primary cancers exhibited cytoplasmic membrane immunopositivity for CD44. 46% of primary tumours which have metastasied to axillary lymph nodes were CD44 positive whereas 30% of tumours which have not metastasised expressed CD44. CD44 positivity was expressed by 20% of grade 1, 31% grade 2 and 58% grade 3 tumours. Our results suggest that CD44 may have a role in the progression of breast cancer and emphasise the need to investigate its interaction with other mechanisms of cancer advancement.