Angiomyolipoma with epithelial cysts (AMLEC): a rare but distinct variant of angiomyolipoma.

Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Diagnostic Pathology (Impact Factor: 2.41). 02/2007; 2:11. DOI: 10.1186/1746-1596-2-11
Source: PubMed

ABSTRACT Angiomyolipoma with epithelial cysts (AMLEC) is a recently described distinct cystic variant of angiomyolipoma (AML). To date 15 cases of AMLEC have been reported in 2 case series. We report the 16th case in a 39-year-old female. Her left kidney tumor was discovered incidentally. Partial nephrectomy was performed. Histologically, the tumor was composed of three components: 1) epithelial cysts lined by cuboidal to hobnail cells; 2) compact subepithelial mullerian-like AML stroma with admixed chronic inflammation; and 3) muscle-predominant AML with dysmorphic blood vessels exterior to the subepithelial stroma. Immunohistochemically, the subepithelial stroma stained most intensely with HMB-45 and Melan-A, whilst the muscle-predominant AML areas stained most intensely with smooth muscle actin and desmin. Estrogen receptor (ER), progesterone receptor (PR), and CD10 stained most intensely in the subepithelial stroma. The cyst lining was positive for pancytokeratin, but negative for HMB-45, Melan-A, ER, PR, and CD10. The patient is alive with no evidence of disease, 12 months postoperatively, and yearly follow-up CT scans are planned.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Hepatic epithelioid angiomyolipoma (AML) is a rare lesion that is characteristically composed of a predominant or exclusive population of epithelioid cells coexpressing melanocytic and myogenic markers. The cystic variant of epithelioid AML is exceedingly uncommon. In this study, we present the clinicopathological features of a case of hepatic epithelioid AML with remarkable cystic degeneration in a 34-year-old female as well as with a literature review. A magnetic resonance imaging scan revealed a well-defined 30 cm × 25 cm hepatic mass. Sectioning of the well-defined mass revealed a non-encapsulated tumor that was multiloculated with amorphous necrotic tissue and hemorrhagic fluid. The inner cystic wall was rough and brownish-black in color. Microscopically, the tumor largely consisted of epithelioid cells that comprised approximately 95% of the total neoplastic components but also contained some spindle myoid cells, mature fat, and a thick-walled vasculature. Both intracellular and extracellular hyaline globules were frequently identified. Necrosis and invasive growth patterns were also present. By immunohistochemistry, spindle-epithelioid neoplastic cells were variably positive for Melan-A, HMB45, and SMA but were uniformly negative for epithelial and hepatocytic markers. This is the third report of a cystic AML in liver. The patient was followed for 71 months without any evidence of metastasis or recurrence.
    International journal of clinical and experimental pathology. 01/2014; 7(9):6364-9.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Angiomyolipoma is the most common benign solid renal neoplasm observed in clinical practice. Once thought to be a hamartoma and almost always diagnosed by the imaged-based detection of fat, angiomyolipomas are now known to consist of a heterogeneous group of neoplasms. Although all are considered perivascular epithelioid cell tumors, many display different pathology, imaging features, and clinical behavior. The importance of understanding this group of neoplasms is emphasized by the fact that many types of angiomyolipoma contain little to no fat, and despite being benign, sometimes escape a pre-operative diagnosis. These types of angiomyolipomas can all be considered when encountering a renal mass that is both hyperattenuating relative to renal parenchyma on unenhanced CT and T2-hypointense, features that reflect their predominant smooth muscle component. We review recent developments and provide a radiological classification of angiomyolipomas that helps physicians understand the various types and learn how to both diagnose and manage them.
    Abdominal Imaging 02/2014; 39(3). · 1.91 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Introduction Angiomyolipomas belong to the family of PEComas. They are the most common mesenchymal renal tumours. Classic angiomyolipoma is composed of smooth muscle, thick abnormal blood vessels and mature adipose tissue. A new subtype of angiomyolipoma has been described recently, with 16 cases reported to date, containing macro- and/or microscopic epithelial cysts, surrounded by a «cambium-like» layer and with Müllerian type stroma, which are positive for melanocytic markers, CD10 and oestrogen and progesterone receptors. These neoplasms are more frequent in women and are usually sporadic, although they are can occur as part of the tuberous sclerosis complex. Clinical findings Here we report a sporadic case of angiomyolipoma with epithelial cysts occurring in a 30 year old man with untreated gynaecomastia who presented with left ureteral lithiasis. An apparently solid 1.8 cm left renal tumour which contained microscopic epithelial cysts was revealed; morphologically it corresponded to an angiomyolipoma with epithelial cysts. Discussion Although these tumours have a distinct histolology, differential diagnosis may include several different benign entities, such as cystic nephroma, mixed epithelial and stromal tumour (MEST) of the kidney, including PEComa, as well as malignant neoplasms such as renal cell carcinomas (NOS, multicystic and sarcomatoid), amongst others. Angiomyolipoma with epithelial cysts behaves in the same benign fashion as angiomyolipoma.
    Revista Española de Patología. 04/2009; 42(2).

Full-text (2 Sources)

Available from
May 27, 2014