Clear cell mammary malignant myoepithelioma with abundant glycogens

Excellent long term oncological outcome in a patient with rare glycogen rich clear cell carcinoma of breast following breast conservation surgery

INTRODUCTION

We present a case report of excellent oncological outcome after 7-year follow up in a female Indian patient with pT2N3aM0 rare GRCC of the breast following breast conservation surgery and appropriate adjuvant treatment. Glycogen rich cell carcinoma (GRCC) is a rare subtype of primary malignant neoplasm of the breast which is not commonly discussed. Only approximately 288 cases have been reported since its first description globally with reports of varying prognosis. Even less (4 patients), which have been reported from India have described only clinic pathological features. This is first case report of patient from India discussing long term oncological outcome of a patient with rare GRCC (pT2N3aMO) of the breast following breast conservation surgery and appropriate adjuvant treatment. A 41-year-old lady presented to us with history of 2 × 2 cm right breast lump for 2 weeks. A BIRAD IV hypo echoic lesion with slightly irregular margins in the upper outer quadrant of the right breast and right axillary lymphadenopathy was reported in mammogram. PET CT showed metabolically active lesion 2.3 × 1.3 cm enhancing nodule with spiculated margins at the same site (SUV-10.8) with metabolically active right axillary metastatic lymphadenopathy (SUV-11) with no distant metastases. Core biopsy indicated Ductal carcinoma. Patient underwent right breast conservation surgery (Wide local excision and oncoplasty with axillary clearance) uneventfully followed by appropriate adjuvant treatment (Chemotherapy, Targeted treatment, Radiotherapy). The final pathological stage was Glycogen rich clear cell carcinoma, pT2N3a M0 with Her2 positive but negative for ER and PR with Ki 67-50 %. The patient had excellent outcome and was alive and cancer free even after 7 years follow up.

CONCLUSION

The purpose of reporting this case is to increase the knowledge about this rare subtype of breast cancer which underwent organ preservation. This case report reveals that clinical behavior and oncological outcome of GRCC breast can be unexpected, unusual, varied and even good, contrary to recent 2019 SEER data (Zhou Z, Kinslow CJ, Hibshoosh H, et al. Clinical features, survival and prognostic factors of glycogen-rich clear cell carcinoma (GRCC) of the breast in the US population. J Clin Med. 2019; 8: pii: E246).

Glycogen-rich Clear Cell Carcinoma of the Breast: A Comprehensive Review

Glycogen-rich clear cell carcinoma (GRCC) is a very rare form of primary breast cancer (<0.1% of all breast cancers). It is characterized by the presence of neoplastic cells with a glycogen-abundant clear cytoplasm (the Periodic Acid Schiff-positive, diastase-sensitive). The expression of steroid receptors (estrogen and progesterone receptors) has been variably reported (35% to 100% of the cases), whereas most studies reported low human epidermal growth factor receptor 2 positivity in GRCC. High androgen receptor positivity without androgen receptor splice variant-7 was reported in one recent study. Although sparse, the preliminary theranostic data on GRCC indicate the potential of targeted treatments in selected cases (antiandrogen, PIK3CA, and immune checkpoint inhibitors). Because of its rarity, the prognosis for GRCC patients remains controversial. Herein, we comprehensively appraise the epidemiological, morphologic, molecular, and clinical characteristics of this rare mammary malignancy.

Malignant myoepithelioma of the breast: a case report and review of literature

In this article, we described a malignant myoepithelioma of the breast (MMB) in a 69-year-old woman. Breast cancer derived from myoepithelial cells is very rare, usually benign. The diagnosis of MMB based on histological and immunohistochemical finding. In this case, the author diagnosed the tumor as MMB, because tumor tissues were immunopositive for 34βE12, P63, SMA, S-100, CD10, E-Cad and Ki-67, and immunnegative for CK5/6, desmin, ER, PR and C-erbB-2, because tumor tissue showed invasive growth and local hemorrhage or necrosis, suggesting malignant, and also because there was a transition between the tumor cells and hyperplastic myoepithelium of non-tumorous ducts. The patient's postoperative recovery is smooth and regular following of patient is essential.

Myoepithelial carcinoma of the breast treated with surgery and chemotherapy

Myoepithelial carcinoma (malignant myoepithelioma) of the breast is a rare tumor, for which only a limited number of reports have been published. Most of the reports emphasized diagnosis and pathology but not biological behavior and treatment. We report a 61-year-old patient with breast myoepithelial carcinoma who developed locoregional and distant metastases and received many chemotherapy regimens. She presented with an elastic hard mass of the left breast. Breast conserving surgery was performed as part of both diagnosis and treatment. From the results of histological and immunohistochemical examinations, this case was considered to be a myoepithelial carcinoma. Fifteen months after the completion of adjuvant radiotherapy, distant metastasis of the left parasternal lymph node metastasis developed. She was treated by further excision and received a total of four regimens of chemotherapy including a combination of doxorubicin and cyclophosphamide. She received chemotherapy for 20 months after the diagnosis of metastasis.

Hypoxia-inducible factor 1-mediated regulation of PPP1R3C promotes glycogen accumulation in human MCF-7 cells under hypoxia

Hundreds of genes can be regulated by hypoxia-inducible factor 1 (HIF1) under hypoxia. Here we demonstrated a HIF1-mediated induction of protein phosphatase 1, regulatory subunit 3C gene (PPP1R3C) in human MCF7 cells under hypoxia. By mutation analysis we confirmed the presence of a functional hypoxia response element that is located 229bp upstream from the PPP1R3C gene. PPP1R3C induction correlates with a significant glycogen accumulation in MCF7 cells under hypoxia. Knockdown of either HIF1α or PPP1R3C attenuated hypoxia-induced glycogen accumulation significantly. Knockdown of HIF2α reduced hypoxia-induced glycogen accumulation slightly (but not significantly). Our results demonstrated that HIF1 promotes glycogen accumulation through regulating PPP1R3C expression under hypoxia, which revealed a novel metabolic adaptation of cells to hypoxia.

Glycogen-rich clear cell mammary malignant myoepithelioma

Primary clear cell tumors of the breast are uncommon and often present a diagnostic challenge. We describe an extremely rare case of glycogen-rich clear cell malignant myoepithelioma in a 43-year-old woman. Histologically, this tumor is composed of clear cells with abundant cytoplasmic glycogen particles. Immunohistochemically, these tumor cells show co-expression of vimentin, smooth muscle actin, epithelial membrane antigen, S-100 protein, and cytokeratin as evidence of myoepithelial cell tumor. The pathological staging of the patient is IIB (pT3N0M0) and the nuclear grading is 2. The patient demonstrated no evidence of recurrence or metastasis over a period of 42 months. We suggest that glycogen-rich clear cell malignant myoepithelioma be included in the histological differential diagnosis of clear cell tumors of the breast.

Metastatic myoepithelioma of the breast

Myoepitheliomas are typically benign tumours arising from exocrine glands. There have only been five reports of malignant myoepitheliomas from breast origin previously published in the English literature. This report describes a patient with myoepithelioma arising in the breast which later metastasized despite the primary tumour having benign histological features. Impaired immune function due to end-stage renal failure and haemodialysis may have contributed to the malignant potential of her tumour. The literature regarding myoepithelial tumours is reviewed. All breast myoepitheliomas should be managed as potentially malignant tumours with appropriate surgical clearance and staging.

Myoepithelial markers are expressed in at least 29% of oestrogen receptor negative invasive breast carcinoma

Around 20% of invasive breast carcinoma are oestrogen receptor alpha (ER) negative. Theoretically, this negativity could be either due to the result of downregulation of ER expression in the tumour cells, or the result of the tumour being derived from or differentiating towards cells which normally lack that expression. Normal basal, including myoepithelial, cells of the breast are ERnegative. CD10, smooth muscle actin and S100 are markers of these basal cells that can be used for their demonstration in routinely processed sections. This study was aimed at comparing the incidence of positivity for three myoepithelial markers in ER-negative and ER-positive invasive breast carcinoma. We have examined sections of 117 cases of breast carcinoma, including 77 ER-negative and 40 ER-positive cases, for the expression of CD10, smooth muscle actin and S100, using the avidin-biotin complex immunoperoxidase technique. A tumour was considered positive if more than 10% of the tumour cells were positively stained. In all, 36 (47%) ER-negative tumours were positive for one or more of these myoepithelial markers. The percentage of positively stained tumour cells varied between 30 and 100%. Of the 40 ER-positive tumours, only three (8%) were positive; two for S100 and one for actin, with none being positive for CD10. If cases stained only with S100 are excluded, as some of these may represent luminal differentiation, definite myoepithelial differentiation seems to be present in 29% (22/77) of ER-negative tumours as compared with 2.5% (1/40) of ER-positive tumours; a difference which is highly significant (P<0.001). It is suggested that at least 29% of ER-negative invasive breast carcinomas may be derived from or differentiating along the direction of basal nonconventional luminal epithelial breast cells that normally lack the expression of ER but totally or partially express various myoepithelial markers. Such tumours might need a different therapeutic approach.

Clinical presentation and long-term outcome of pure myoepithelial carcinoma of the breast

INTRODUCTION

Pure myoepithelial carcinoma of the breast is a rare tumour of controversial histogenesis. Little is known about its natural history and long-term outcome following treatment.

METHODS

All patients with pure myoepithelial carcinoma treated at our institution between 1970 and 2001 were studied with respect to pathological features, outcome and prognosis.

RESULTS

Six patients were identified. The median age was 60 (40-66) years and median follow-up was 34.5 months (range 14-76) months. Four tumours were T1 and one was T2 (one tumour size unknown). There were two moderately differentiated and three well-differentiated tumours (grade could not be assessed in one patient). Oestrogen and progesterone receptor could be assessed in five patients and all were negative. Primary treatment was wide local excision with clear radial margins. Lymph node assessment was negative in all patients. One patient received adjuvant radiotherapy. Three patients developed local recurrence at 15, 38 and 50 months and two patients developed distant metastasis at 30 and 79 months. The local recurrences were treated by further excision but two patients developed distant metastasis at intervals of 15 and 26 months, respectively. Two patients have died of the disease and four remain well. The 2-year and 5-year survival was 88% (SE, 6) and 55% (SE, 16), respectively. Large tumour size is a prognostic indicator of poor outcome.

CONCLUSION

Pure myoepithelial carcinoma of the breast adopts an aggressive clinical course with an outcome comparable to poorly differentiated adenocarcinoma of the breast.

Salivary-type neoplasms of the breast and lung

Salivary-type tumors occur in multiple sites in the human body, likely related to a basic structural homology between exocrine glands in these different anatomic areas. This paper reviews these salivary gland tumor types in breast tissue and lung. Salivary-type tumors of both breast and lung are relatively uncommon in comparison to their salivary gland counterparts. This may be attributable in part to lack of familiarity with these tumors in extra-salivary sites, and in part to histologic overlap with other primary and metastatic tumor types. Recognition of these entities is improving as the clinical and pathologic features are better delineated, and tumors are more accurately classified. Prediction of malignant behavior is not always possible in these unusual sites. In some instances, such as adenoid cystic carcinoma, behavior is known to differ considerably from that of analogous primary salivary gland tumors and in other instances there are simply too few reported cases to allow for adequate prognostication. In fact, more recent papers discuss the need to consider a spectrum encompassing benign and malignant lesions, in both breast and lung. Of course, some entities show clear-cut evidence of malignancy with documented potential for metastasis, others show bland features and well-reported benign behavior, and the less well-defined entities reside between these two extremes. The molecular pathology of salivary gland tumors has been reasonably well investigated in that location; however; there are few molecular studies devoted to salivary-type tumors of the breast and lung. This represents a potential area for future growth in further clarifying these tumors and their behavior.