Retroperitoneal epithelioid angiomyolipoma leading to fatal outcome

Subtype-Based Analysis of Cell-in-Cell Structures in Esophageal Squamous Cell Carcinoma

Cell-in-cell (CIC) structures are defined as the special structures with one or more cells enclosed inside another one. Increasing data indicated that CIC structures were functional surrogates of complicated cell behaviors and prognosis predictor in heterogeneous cancers. However, the CIC structure profiling and its prognostic value have not been reported in human esophageal squamous cell Carcinoma (ESCC). We conducted the analysis of subtyped CIC-based profiling in ESCC using "epithelium-macrophage-leukocyte" (EML) multiplex staining and examined the prognostic value of CIC structure profiling through Kaplan-Meier plotting and Cox regression model. Totally, five CIC structure subtypes were identified in ESCC tissue and the majority of them was homotypic CIC (hoCIC) with tumor cells inside tumor cells (TiT). By univariate and multivariate analyses, TiT was shown to be an independent prognostic factor for resectable ESCC, and patients with higher density of TiT tended to have longer post-operational survival time. Furthermore, in subpopulation analysis stratified by TNM stage, high TiT density was associated with longer overall survival (OS) in patients of TNM stages III and IV as compared with patients with low TiT density (mean OS: 51 vs 15 months, P = 0.04) and T3 stage (mean OS: 57 vs 17 months, P=0.024). Together, we reported the first CIC structure profiling in ESCC and explored the prognostic value of subtyped CIC structures, which supported the notion that functional pathology with CIC structure profiling is an emerging prognostic factor for human cancers, such as ESCC.

Retroperitoneal Sclerosing Angiomyolipoma with Long-Term Follow up: A Case Report with Unique Clinicopathologic and Genomic Profile

Sclerosing angiomyolipoma (sAML) is a rare variant of the perivascular epithelioid tumors exhibiting distinct morphology with extensive stromal hyalinization, which makes it challenging to recognize. It often lacks an adipose tissue component and melanocytic markers may be expressed only focally, further posing a diagnostic challenge. Here, we report a case of sAML of the left pararenal retroperitoneum in a 52-year-old woman with 92 months of clinical follow up and discuss the histologic features, immunoprofile, molecular alterations, and differential diagnoses that can aid in the diagnosis of this unique and rare entity.

[A case of malignant perivascular epithelioid cell tumor of the retroperitoneum with multiple metastases]

Perivascular epithelioid cell tumors (PEComas) are unusual mesenchymal neoplasms composed of histologically and immunohistochemically distinct perivascular epithelioid cells (PECs). Although PEComas have the potential to behave in a malignant fashion, malignant PEComas arising from the retroperitoneum are extremely rare. A 68-year-old woman presented with a painful palpable mass in her left upper abdomen. Computed tomography of the abdomen showed a 9 cm sized heterogeneous mass in left para-aortic space and multiple hypervascular nodules in the liver. (18)F-fludeoxyglucose-PET/CT showed multifocal hyper-metabolic lesions in retroperitoneum, liver, and skeletal bones. Percutaneous needle biopsies were done on the retroperitoneal and hepatic mass. Both specimens were positive for human melanoma black-45 (HMB-45) on histological and immunohistochemical staining which was compatible with PEComas. Herein, we report a rare case of retroperitoneal PEComa with multiple metastases involving liver and bone at initial diagnosis that exhibited aggressive behavior and resulted in a devastating prognosis.

Aurora A orchestrates entosis by regulating a dynamic MCAK-TIP150 interaction

Entosis, a cell-in-cell process, has been implicated in the formation of aneuploidy associated with an aberrant cell division control. Microtubule plus-end-tracking protein TIP150 facilitates the loading of MCAK onto the microtubule plus ends and orchestrates microtubule plus-end dynamics during cell division. Here we show that TIP150 cooperates with MCAK to govern entosis via a regulatory circuitry that involves Aurora A-mediated phosphorylation of MCAK. Our biochemical analyses show that MCAK forms an intra-molecular association, which is essential for TIP150 binding. Interestingly, Aurora A-mediated phosphorylation of MCAK modulates its intra-molecular association, which perturbs the MCAK-TIP150 interaction in vitro and inhibits entosis in vivo. To probe if MCAK-TIP150 interaction regulates microtubule plasticity to affect the mechanical properties of cells during entosis, we used an optical trap to measure the mechanical rigidity of live MCF7 cells. We find that the MCAK cooperates with TIP150 to promote microtubule dynamics and modulate the mechanical rigidity of the cells during entosis. Our results show that a dynamic interaction of MCAK-TIP150 orchestrated by Aurora A-mediated phosphorylation governs entosis via regulating microtubule plus-end dynamics and cell rigidity. These data reveal a previously unknown mechanism of Aurora A regulation in the control of microtubule plasticity during cell-in-cell processes.

Fatal malignant metastastic epithelioid angiomyolipoma presenting in a young woman: case report and review of the literature

Epithelioid angiomyolipomas (EAMLs) are rare mesenchymal tumors whose malignant variant is extremely uncommon and highly aggressive. Treatment strategies include chemo radiation, transcatheter arterial embolization and surgical resection, which has remained the mainstay treatment. Targeted therapies including mammalian target of rapamycin (mTOR) inhibitors such as Temsirolimus may offer some hope for progressive malignant EAMLs that are not amenable to other treatment modalities. We report a fatal case in a young female who presented with rapidly progressive metastatic EAML that did not respond to mTOR therapy. The literature has shown reduction in tumor burden with the use of mTOR inhibitors, but unfortunately due to the rarity of malignant EAML, a meaningful approach to treatment remains challenging.

The cell biology of cell-in-cell structures

For decades, authors have described unusual cell structures, referred to as cell-in-cell structures, in which whole cells are found in the cytoplasm of other cells. One well-characterized process that results in the transient appearance of such structures is the engulfment of apoptotic cells by phagocytosis. However, many other types of cell-in-cell structure have been described that involve viable non-apoptotic cells. Some of these structures seem to form by the invasion of one cell into another, rather than by engulfment. The mechanisms of cell-in-cell formation and the possible physiological roles of these processes will be discussed.

Metastatic retroperitoneal epithelioid angiomyolipoma

Angiomyolipoma (AML) is a rare benign neoplasm that usually arises in the kidneys, but may rarely originate in sites such as the retroperitoneum, liver and bone. It is characterised by an intimate admixture of blood vessels, smooth muscle and fat. This multiphasic composition allows for its recognition on ultrasound and CT scan examination. Metastases are exceedingly uncommon, and only one other case of metastatic extrarenal AML exists in the literature. Histological variants of AML such as epithelioid angiomyolipoma (EAML) are considered to be locally aggressive. A unique case of an EAML of the retroperitoneum that metastasised to the liver and bone in an 80-year-old woman is described.

Abdominopelvic perivascular epithelioid cell tumor with overt malignancy: a case report

Perivascular epithelioid cell tumor (PEComa) is a group of rare tumors composed of epithelioid cells with characteristic perivascular distribution and co-expression of the melanogenic marker HMB-45 and muscular markers. There are no documented parameters referring to the biologic behavior of PEComa. We report an abdominopelvic PEComa with overt malignancy in a 16-year-old girl. Histologically, the tumor showed the typical morphophenotypic characteristics of PEComa. Though the cytologic appearance of the tumor cells was relatively bland, the extensive necrosis, presence of lymph node metastases, and surrounding tissue invasion were all indicative of malignancy. Relapse of the tumor with multiple lymphadenopathy shortly after debulking surgery for the primary lesion, and postoperative adjuvant chemotherapy, further denoted its aggressive behavior.

Reasons to reconsider the significance of apoptosis for cancer therapy

In recent years, the significance of apoptosis as a process in cell loss from normal tissue and tumours has been critically reviewed. In addition, the general lack of a correlation between radiation or drug-induced apoptosis and cell survival responses (using the clonogenic assay) in tumour cells has been demonstrated. Several different reasons have been discussed by other authors. It is the purpose of this review to argue that there are many different forms of cell death (terminal differentiation, micronucleation, mitotic catastrophe or multinucleation) that, like apoptosis, are regulated by the cell. In this context, apoptosis was the first cell death mechanism associated with active involvement of the cell (signal transduction). Furthermore, a large variety of different in vitro and a few in vivo models published so far show that the form of cell death can shift from, for example, mitotic catastrophe to apoptosis. The shift appears to be a general principle and depends on the cell model examined, the stressor type and the stressor intensity. These considerations help to explain the absence of a simple link between apoptosis and clonogenicity and suggest how to overcome that limitation, which has implications for the significance of apoptosis where the diagnosis and prognosis of cancer are concerned.

Malignant monotypic epithelioid angiomyolipoma of the retroperitoneum

Monotypic epithelioid angiomyolipoma (EAML) is an uncommon variant of angiomyolipoma, occurring primarily in the kidney and characterized by a predominance of HMB-45-positive epithelioid cells. EAML is generally considered a benign neoplasm, though rare cases exhibiting malignant behavior have been reported. We describe a patient with a primary retroperitoneal monotypic EAML, composed exclusively of atypical epithelioid cells, which metastasized to the liver and the mediastinum. This case represents, to our knowledge, the first description of metastatic disease occurring in an EAML of this particular site.

Contemporary diagnosis and management of renal angiomyolipoma

PURPOSE

We present a comprehensive resource that summarizes contemporary advances relevant to the clinical management of renal angiomyolipoma.

MATERIALS AND METHODS

A MEDLINE search was done using the key words angiomyolipoma, hemangioma or lipoma and kidney neoplasm, and therapeutic embolization. References from these articles were reviewed to identify additional relevant source material. We identified 13 series published since 1986 comprising 336 patients as well as 24 reports of therapeutic embolization for angiomyolipoma, comprising 76 patients. To our knowledge we report the largest compilation series to date.

RESULTS

Angiomyolipoma is generally benign, although an uncommon subtype (epithelioid angiomyolipoma) may behave more aggressively. Tuberous sclerosis associated angiomyolipoma tends to be larger, multiple and more likely to cause spontaneous hemorrhage than the sporadic entity. Tumors that hemorrhage tend to be larger. Computerized tomography or magnetic resonance is usually sufficient for diagnosis. Biopsy is rarely useful. Primary indications for intervention include symptoms such as pain or bleeding or suspicion of malignancy. Prophylactic intervention is justifiable for large tumors, in females of childbearing age or in patients in whom followup or access to emergency care may be inadequate. Recent advances that have affected management include improved understanding of tuberous sclerosis complex and angiomyolipoma genetics, the identification of molecular markers that facilitate histopathological diagnosis, and the refinement of embolization and partial nephrectomy techniques.

CONCLUSIONS

Although some cases of angiomyolipoma may require complete nephrectomy, most can be managed by conservative nephron sparing approaches. Ongoing research into the molecular biology and clinical behavior of angiomyolipoma may improve our ability to manage these lesions.

Epithelioid angiomyolipoma of the ovary: a case report and literature review

Angiomyolipoma (AML) is a benign mesenchymal neoplasm that mainly occurs in the kidney either sporadically or in patients with tuberous sclerosis complex (TSC). Extrarenal AML is uncommon. We describe a 39-year-old female with a history of TSC and bilateral multicentric renal AML who presented with a persistent cystic ovarian mass that fluctuated in size during 2 years of ultrasonographic observation before its removal by salpingo-oophorectomy. The 4.5-cm mass was solid and cystic and tan-yellow. Microscopic examination showed an admixture of epithelioid cells, smooth muscle bundles, large thick-walled blood vessels, and mature adipose tissue. The epithelioid cells had abundant eosinophilic cytoplasm and many had bizarre atypical nuclei including multinucleated forms. Mitoses were rare. Typical smooth muscle cells and the epithelioid cells were strongly immunoreactive for HMB-45. To our knowledge, this represents the first report of an AML arising in the ovary. The differential with other oxyphilic tumors of the ovary is discussed.

Monotypic angiomyolipoma of the nasal cavity: a heretofore undescribed occurrence

A monotypic angiomyolipoma of the nasal cavity in a 34-year-old woman is described. Tumor cells were spindled or epithelioid and contained glycogen and diastase-resistant PAS-positive granules. There were few mitoses, and necrosis was absent, indicating a benign tumor. The stroma was markedly vascular, and a few adipocytes were seen in one area. Cells were positive for melanocyte and muscle markers. Electron microscopy revealed abundant dense granules. Although melanin was absent histochemically, it was present using a chemical assay, and the granules may, therefore, be atypical melanosomes. Fine actin filaments, attachment plaques and lamina were present. Initial assessment of the lesion indicated malignant melanoma, but the immunostaining and histologic features indicated monotypic angiomyolipoma. To the best of our knowledge, this is the first such case in the nasal cavity.