Frequent low-level mutations of protein kinase D2 in angiolipoma.

Tumours displaying differentiation towards normal fat constitute the most common subgroup of soft tissue neoplasms. A series of such tumours was investigated by whole-exome sequencing followed by targeted ultra-deep sequencing. Eighty per cent of angiolipomas, but not any other tumour type, displayed mutations in the protein kinase D2 (PRKD2) gene, typically in the part encoding the catalytic domain. The absence of other aberrations at the chromosome or RNA level suggests that PRKD2 mutations are critical for angiolipoma development. Consistently, the mutated PRKD2 alleles were present at low (3-15%) frequencies, indicating that only a subset of the tumour cells is affected. Indeed, by sequencing mature fat cells and other cells separately, the former typically showed the highest mutation frequencies. Thus, we hypothesize that altered PRKD2 signalling in the adipocytic cells drives tumourigenesis and, in agreement with its pivotal role in angiogenesis, induces the vessel formation that is characteristic for angiolipoma. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Hemorrhagic onset of spinal angiolipoma.

Spinal angiolipomas are rare benign tumors that generally induce slow progressive cord compression. Here, the authors describe a case of sudden-onset palsy of the lower extremities caused by hemorrhagic spinal angiolipoma. An emergent laminectomy was performed to achieve total lesion removal. Follow-up examinations indicated neurological improvement and the absence of recurrence.

[Sonographic appearance of benign subcutaneous nodules--including color Doppler sonography].

OBJECTIVE: Color Doppler sonography is used to distinguish malignant from benign subcutaneous nodules because many malignant tumors show an increased number of vessels. But benign lesions, such as inflammatory epidermal cysts, pilomatricomas, palmoplantar fibromatoses show vascular flow signals. We analyze diagnostic factors for subcutaneous nodules on the basis of ultrasonographic appearance including color Doppler sonography. METHODS: We evaluated with sonography 79 subcutaneous nodules in histopathologically proven cases. RESULTS AND DISCUSSION: The diagnostic findings for 28 epidermal cysts were increased posterior echo(sensitivity 77%, specificity 90%). Vascular flow signals were seen in 7 cases(25%). The signals were seen from periphery to adjacent zone of the mass. They were accompanied by inflammatory granulation tissues histologically. The percentage of blood flow may be related to the percentage of "ruptured" epidermal cysts. Pilomatricomas (n = 9) had internal echogenic foci or Doppler flow signals, and no posterior enhancement (sensitivity 89%, specificity 78%). Seven pilomatricomas showed Doppler flow signals in the mass. The percentage of flow signals is explained by the degree of internal echogenic foci because remarkable calcium deposits producing posterior acoustic shadowing prevent us from flow signals. Palmoplantar fibromatoses (n = 5) were ill-defined margins and showed internal vascularity with no posterior enhancement (sensitivity 80%, specificity 94%). CONCLUSION: More benign lesions showed vascular flow signals than reported previously. We have to diagnose subcutaneous nodules referring to not only color Doppler but also gray scale sonography.

Infiltrating angiolipoma of the nasopharynx: adjacent to an aberrant internal carotid artery.

Infiltrating angiolipomas are tumors consisting of adipose tissue marked by vascular proliferation and are nonencapsulated or partially encapsulated. These tumors are very rare in the head and neck. This is the first case report of infiltrating angiolipoma arising from the nasopharynx causing the Eustachian tube dysfunction. A 29-year-old female presented with a history of earfullness and nasal obstruction. A sessile mass was found at the left superior-lateral wall of the nasopharynx. The mass was excised by a transnasal endoscopic approach. The tumor was adhered to the cavernous sinus containing an aberrant internal carotid artery that was located in an abnormally low portion in the cavernous sinus. The patient is currently free of growth of remained tumor 4 years after endoscopic surgery.

Epidural angiolipoma is histologically distinct from its cutaneous counterpart in the calibre and density of its vascular component; a case report with review of the literature.

Angiolipoma of the spine is a rare tumour and no studies have investigated a sufficient number of cases to reach general conclusions. Therefore, as yet, the pathological definition of this entity is not well established. The case of epidural angiolipoma reported here and a review of the literature revealed that this entity is distinct from cutaneous angiolipoma in that the calibre of its predominant vascular component is far greater than that of the fat cells. Therefore, epidural angiolipoma can be regarded as not only topographically, but also histologically, distinct from its subcutaneous counterpart.

Subcutaneous angiolipomas: a clinicopathological study of 12 cases.

A total of 12 cases of angiolipomas were received over a period of 2 years and comprised 13% of all lipomatous tumors. There were eleven males and one female. Pain/tenderness was the presenting feature in 11 of the cases and in all the cases, the tumors were located on upper extremities or trunk. Grossly, the tumors were encapsulated and histologic examination revealed fibrin thrombi in many capillaries, in all cases. None of these tumors were infiltrating into the surrounding skeletal muscle or soft tissue.

Angiolipoma of the buccal mucosa: a possible role of mast cell-derived VEGF in its enhanced vascularity.

A case of angiolipoma occurring in the buccal mucosa of a 69-year-old male is described. The patient had noticed a painless mass in his buccal mucosa for 2 years. The surgically removed tumor, measuring 9 mm in diameter, was mainly located in the submucosal layer with focal expansion into the muscle layer. Histologically, the tumor was well-demarcated and composed of proliferations of mature fat cells and fibrous connective tissue containing many small blood vessels, which were evenly distributed. There was diffuse infiltration of a large number of mast cells, which were immunopositive for vascular endothelial growth factor (VEGF) especially around blood vessels, suggesting that VEGF produced by mast cells in angiolipomas plays an important role in the vascular proliferation in this particular tumor.

Subacute paraparesis induced by venous thrombosis of a spinal angiolipoma: a case report.

STUDY DESIGN: A case report of spinal extradural angiolipoma, a rare tumor that can cause spinal cord compression, is presented with a complete review of the literature related to this disorder. OBJECTIVES: To discuss venous thrombosis involving the angiolipoma in the development of subacute paraparesis. SUMMARY OF BACKGROUND DATA: This case shows that venous thrombosis of a spinal angiolipoma can precipitate the subacute onset of paraparesis. METHODS: Medical history, physical findings, and the results of imaging and histopathologic studies were analyzed to elucidate the pathogenesis of the patient's subacute onset of paraparesis. A bilateral T3-T7 laminectomy was performed, and although the tumor was extremely hemorrhagic, it was mobilized easily off the compressed dura to achieve resection. RESULTS: The postoperative course was uneventful. One month after her surgery, the patient's myelopathic symptoms had resolved, and the she was able to return to work. CONCLUSION: Because the prognosis after surgical management of these lesions is favorable, the diagnosis of thrombosis involving a spinal angiolipoma should be considered in the differential diagnosis of subacute spinal cord compression.

Vascular myxolipoma ("angiomyxolipoma") of the spermatic cord.

We report a case of vascular myxolipoma of the spermatic cord occurring in a 32-year-old man. Clinically, the lesion was mobile and tender. Pathologically, the tumor was encapsulated and rubbery with a beige-yellow gelatinous cut surface. Microscopically, the lesion consisted of adipose tissue with extensive areas of myxoid change and an abundance of thin and thick-walled blood vessels. We consider this tumor a vascular type of myxolipoma and propose the term angiomyxolipoma. The lesion should be distinguished from liposarcoma and aggressive angiomyxoma, which have malignant or aggressive clinical course.

Cellular angiolipoma.

A 25-year-old man had a 5-year history of multiple tender lesions of both extremities and trunk. Biopsy found an encapsulated subcutaneous nodule composed of numerous small, well-formed blood vessels, some filled with fibrin thrombi. This lesion was made up > 99.9% of blood vessels with only a minimal amount of adipose tissue. We believe our case is in the spectrum of angiolipoma even though it is made up almost entirely of a vascular component. These tumors may be confused with other multiple or eruptive vascular lesions that have a more ominous clinical course. This case is being reported to stress that multiple or eruptive "vascular" lesions do not always reflect an underlying immunosuppression or malignancy.

Mast cells in angiolipomas and hemangiomas of human skin: are they important for angiogenesis?

To characterize the potential role of mast cells (MC) in angiogenesis, this study tests the hypothesis that MC may be more abundant in angiolipomas than in classic lipomas. MC counts were compared in 13 subcutaneous angiolipomas and 15 subcutaneous classic lipomas stained with Giemsa. Angiolipomas had ten times as many MC as did classic lipomas (25.34 +/- 2.83 versus 2.41 +/- 0.37 per mm2, mean +/- SE). To clarify whether this difference was primary (angiogenic activity) or secondary to the increased vascularity, MC were counted in 8 longstanding cutaneous capillary hemangiomas versus 13 cutaneous capillary hemangiomas of recent onset (pyogenic granulomas). If MC were mediating primary angiogenesis, one would expect them to be present in greater numbers in early than in late hemangiomas. To the contrary, however, long-standing hemangiomas were found to have significantly more MC than had those of recent onset (52.48 +/- 14.99 versus 6.59 +/- 3.37 per mm2, mean +/- SE). These results suggest that MC may not play an essential, early role in the proliferation of blood vessels in angiolipomas and hemangiomas, but rather may be related to maturation of blood vessels in these tumors.

Intracranial suprasellar angiolipoma: ultrastructural and immunohistochemical features.

The authors present ultrastructural and immunohistochemical characteristics of an intracranial suprasellar tumor displaying features of cavernous angioma with islets of adipose tissue. Electron microscopy revealed thin-walled vessels separated by a loose collagenous stroma containing nests of mature adipocytes as well as fibroblasts, myofibroblasts, mast cells, and a few macrophages. Intracytoplasmic lipid droplets were also identified in scattered pericytes and smooth muscle cells of vascular walls and in the transitional cells resembling smooth muscle cells and adipocytes. Many adipose tissue cells were positive for S-100 protein with polyclonal antibodies. Other lipidized tumor cells were immunoreactive for some or all of the following: smooth muscle-specific actin, factor XIIIa, vimentin, and, occasionally, for desmin. Ultrastructure and immunohistochemistry indicate that in addition to typical adipocytes, lipidized cells of another nature contribute to the characteristic appearance of the adipose tissue component of angiolipoma.