Primary angiosarcoma arising in an angiomyolipoma of the kidney: case report and literature review.

BACKGROUND: Primary angiosarcoma of the kidney is a rare and aggressive malignant tumor presenting with a recognizable vascular differentiation. Its prognosis is fatal and the pathogenesis remains unclear. Renal angiomyolipoma is a relatively infrequent renal cortical neoplasm and is composed of variable proportions of adipose tissue, spindle cells, epithelioid smooth muscle cells and abnormal thick-walled blood vessels. CASE PRESENTATION: Here, we reported a case in which a 64-year-old woman presenting with the chief complaint of a progressively enlarged mass in the left abdomen. Abdominal computed tomography confirmed presence of a tumor measuring 18 cm × 11 cm in the left posterior renal fascia. Microscopic examination and immunohistochemical staining confirmed co-existence of angiomyolipoma and angiosarcoma. Furthermore, the two components interspersed with each other and there were transitional zones between them. CONCLUSIONS: In this case, we described for the first time a primary renal angiosarcoma possibly arising in a pre-existing angiomyolipoma of the kidney.

Hepatic angiomyolipomas may overexpress TFE3, but have no relevant genetic alterations.

The fusion or amplification of TFE3 has been identified as one of the molecular events underlying tumorigenesis in perivascular epithelioid cell tumors (PEComas). TFE3 rearrangements in PEComas are related to the morphological features of the epithelioid appearance and weaker expression of immunohistochemical muscular markers. This study aimed to clarify whether these genetic alterations are involved in hepatic angiomyolipomas (AMLs), which are a member of the PEComa tumor family. We examined 28 liver specimens (15 biopsies and 13 surgical specimens) of hepatic AMLs obtained from 26 patients. Renal AMLs (n=20), extrahepatorenal PEComas (n=3), lymphangiomyomatosis (n=8), and hepatocellular carcinomas (n=40) were used as a control. A histologic comparison between hepatic and renal AMLs revealed that the epithelioid appearance was more common in hepatic tumors (38% versus 0%, P=.006). In immunohistochemistry, the expression of HMB45 and Melan-A appeared to be more widespread in hepatic AMLs than in renal AMLs, whereas smooth muscle actin and desmin were less broadly expressed in hepatic tumors (all P<.001). TFE3 also appeared to be overexpressed in 6 (21%) of 26 hepatic AMLs and 3 (100%) of 3 PEComas, but in none of the renal AMLs. In fluorescence in situ hybridization, although all PEComas harbored a TFE3 rearrangement or amplification, no genetic alterations were found in any hepatic AMLs. In conclusion, although hepatic AMLs and TFE3-rearranged PEComas share pathological features such as the epithelioid appearance and immunoreactivity to TFE3, TFE3 alterations are less likely to be a major molecular event driving tumorigenesis in hepatic AMLs.

Primary hepatic epithelioid angiomyolipoma: A malignant potential tumor which should be recognized.

AIM: To improve the clinical diagnosis and recognition of hepatic epithelioid angiomyolipoma (HEAML). METHODS: Four cases of primary HEAML were confirmed based on the pathology archive system in our hospital from January 2009 to November 2015. The general state, clinical symptoms, imaging manifestations, histological results and immunohistochemistry of these patients were retrospectively reviewed and analyzed. Studies of HEAML published in the last 15 years were collected from PubMed and MEDLINE to summarize the clinical symptoms, imaging characteristics, pathological features and management of HEAML. RESULTS: Four cases of primary HEAML were retrieved from our archives. These included three female patients and one male patient, with a mean age of 41.8 ± 11.5 years (ranging from 31 to 56 years). The mean tumor size was 7.3 ± 5.5 cm (ranging from 3.0 to 15 cm). In the contrast-enhanced imaging, the tumor was obviously enhanced in the arterial phase, but enhanced continuously or exhibited a slow-density masse during the venous and delayed phases. Histologically, the tumors mainly consisted of epithelioid cells that comprised approximately 95% of the total neoplastic mass. Although no metastases occurred in our patients, pathological studies revealed necrosis, mitotic figures and liver invasion in two patients, which indicates aggressive behavior. Immunohistochemical staining revealed that human melanoma black 45 (HMB-45) and Melan-A were positive in 4 cases. We only identified 81 cases with primary HEAML, including our present patients, from 26 articles available from PubMed and MEDLINE. The majority of the papers were published as case reports. Only 5 (5/75, 6%) cases were associated with tuberous sclerosis complex (TSC). More than half (35/66) were discovered incidentally upon physical examination. Approximately 65% (22/34) of the patients were misdiagnosed with HCC or other tumors before surgery. Approximately 10% (8/81) of the patients with HEAML had recurrence or metastasis after surgery, which was a very high and alarming rate. CONCLUSION: HEAML is a very rare primary hepatic tumor that is often misdiagnosed before surgery. Patients should be followed closely after surgery because of its malignant potential.

Granulomatous reaction in hepatic inflammatory angiomyolipoma after chemoembolization and spontaneous rupture.

A 77-year-old Japanese woman was transported to a nearby hospital due to sudden abdominal pain and transient loss of consciousness. Abdominal computed tomography (CT) suggested hemoperitoneum and hepatic nodule. She was conservatively treated. Contrast-enhanced CT two months later revealed an increased mass size, and the enhancement pattern suggested the possibility of hepatocellular carcinoma (HCC). Under a clinical diagnosis of HCC, transcatheter arterial chemoembolization (TACE) was performed. A subsequent imaging study revealed that most of the lipiodol used for the embolization was washed out. Therefore, surgical resection was performed. Histologically, the nodule contained numerous inflammatory cells including small lymphocytes, plasma cells and macrophages. Notably, epithelioid granulomatous features with multinucleated giant cells were observed in both the nodule and background liver. Some of the multinucleated giant cells contained oil lipid. Among the infiltrating inflammatory cells, spindle-shaped, histiocytoid or myoid tumor cells with eosinophilic cytoplasm were found. The tumor cells were positive for Melan A and HMB45. The nodule contained many IgG4-positive plasma cells; these were counted and found to number 72.6 cells/HPF (range: 61-80). The calculated IgG4:IgG ratio was 33.2%. The nodule was finally diagnosed as previously ruptured inflammatory angiomyolipoma modified by granulomatous reaction after TACE.

Primary intranodal cellular angiolipoma.

Angiolipoma is a distinct, benign soft tissue tumor that most commonly occurs in young males as multiple small, subcutaneous, tender to painful nodules with predilection for the forearms. We report a case of angiolipoma that developed within a lymph node. The patient was a 67-year-old man who underwent radical retropubic prostatectomy with diagnostic pelvic lymphadenectomy because of adenocarcinoma of the prostate. The prostate and 3 lymph nodes located in the obturator fossa were removed. On gross examination, the cut surface of 1 of the lymph nodes revealed an 8 x 5 mm, ovoid, sharply demarcated, nonencapsulated, gray lesion being suspicious for adenocarcinoma metastasis. Microscopically, the major portion of the lymph node was replaced by mature metaplastic adipose tissue. The angiolipoma was seen as a well-demarcated, nonencapsulated lesion composed of numerous small blood vessels lined by monomorphous flattened or spindled endothelial cells. Many vascular lumina were filled with fibrin thrombi. There were scanty mature adipocytes. Focally, areas with increased cellularity and a suggestion of solid growth of the endothelial cells were seen. Lymph nodes are known to be a rare primary site of various tumors usually occurring in other organs. The knowledge of these tumors is important in order not to interpret them as metastatic lesions. The most recognized examples are pigmented nevi, palisading myofibroblastoma, various benign epithelial inclusions, serous cystic tumors of borderline malignancy, and hyperplastic mesothelial inclusions. As we present in this report, angiolipoma is another neoplasm whose primary occurrence in the lymph node should not be misinterpreted as a metastatic tumor or malignant vascular tumor.

Angiomyxolipoma (vascular myxolipoma) of subcutaneous tissue.

Three cases of angiomyxolipoma (vascular myxolipoma) have been published to date. We report an angiomyxolipoma located in the subcutaneous tissue of the scalp. Histologically, it consisted of an admixture of paucicellular myxoid areas and mature fat tissue, both containing numerous dilated blood vessels with hyalinized thin walls. The cells in the myxoid areas expressed CD34. This lesion requires differential diagnosis with other benign fat tissue tumors, especially myxoid spindle cell lipoma, superficial angiomyxoma, myxoid liposarcoma, and low-grade myxofibrosarcoma.

Intravascular lymphomatosis presenting within angiolipomas.

This report presents a case of intravascular lymphomatosis identified within an angiolipoma. The patient was a 73-year-old woman with a history of lobular carcinoma of the breast who presented with a chest wall nodule near the site of prior mastectomy. Microscopically, the nodule was composed of encapsulated adipose tissue with an associated vascular proliferation. Many of the vascular lumina were expanded by collections of large pleomorphic cells with vesicular nuclei and prominent nucleoli. These atypical cells displayed immunoreactivity for CD45RB (leukocyte common antigen) and the pan-B cell marker CD20 (L26). The patient subsequently developed multiple lesions of the extremities and died soon after developing symptoms referable to the central nervous system. Intravascular lymphomatosis most commonly presents with central nervous system and dermatologic involvement although any organ system may be affected. Intravascular lymphomatosis is an aggressive neoplasm that is generally diagnosed at postmortem examination. This case shows the protean manifestations of intravascular lymphomatosis and highlights the necessity of considering this malignancy in the differential diagnosis when entertaining the diagnosis of vascular invasion by carcinoma. Ann Diagn pathol 5:103-106, 2001. This is a US government work. There are no restrictions on its use.

Fibrohistiocytic differentiation in subcutaneous fatty tumors. Study of spindle cell, pleomorphic, myxoid, and atypical lipoma and dedifferentiated liposarcoma cases composed in part of CD34+ fibroblasts and FXIIIa+ histiocytes.

Subsets of dendritic cells, fibroblasts which express the human progenitor cell antigen CD34 or histiocytes which express coagulation factor XIIIa (FXIIIa), are present in fat and in collagenous connective tissue. As components of the microvascular unit, these fibrohistiocytic cell subsets may interact during stromal remodeling, repair, and neoplasia. We studied white fat and subcutaneous fatty tumors to determine if CD34 and/or FXIIIa+ "fibrohistiocytic" dendritic cell subsets are involved in their morphogenesis. Three lipomas (L), 1 intramuscular lipoma (IL), 1 myxoid lipoma (ML), 2 pleomorphic lipomas (PL), 2 spindle cell lipomas (SCL), 8 angiolipomas (AN) in 4 patients, 1 atypical lipoma/well-differentiated liposarcoma (AL), 1 de novo dedifferentiated liposarcoma (DL), and 1 recurring atypical myxoid signet ring lipomatous tumor were examined for CD34, FXIIIa and in some cases for CD31, desmin, Ki 67, or S-100. Normal fat has scattered CD34+ dendritic cells and small FXIIIa+ dendritic histiocytes among variably S-100+ adipocytes. The CD34 and FXIIIa+ dendritic cells are more numerous near vessels and within fibrovascular septae. In L and IL, CD34 and FXIIIa+ dendritic cells are activated and some adipocytes express CD34. Mesenchymal areas of SCL, PL, ML, and AL and DL are composed of CD34+ dendritic cells with CD34+ but FXIIIa-negative floret cells in PL or atypical cells in AL and DL. FXIIIa+ dendritic cells are numerous in these lesions, comprising 30-40% of cells in SCL and PL, and 50% in ML, AL, and DL. AN have focal CD34+ interstitial cells and plump FXIIIa+ cells that in one case resembled multivacuolated lipoblasts. The myxoid signet ring lipomatous tumor was CD34 negative with few FXIIIa+ cells. We conclude that subsets of CD34+ and FXIIIa+ dendritic microvascular cells are present in normal fat and proliferate together in various types of lipomas and in at least some dedifferentiated liposarcomas.