Angiomyolipoma of the parotid gland: a case report

Angioleiomyoma of the Parotid Gland Fed by the Superficial Temporal Artery

Angioleiomyoma in the head and neck area is rarely observed. This report introduces 2 cases of angioleiomyoma discovered in the parotid gland, particularly with the superficial temporal artery (STA) as the feeding vessel. Each patient was evaluated preoperatively by clinical manifestation and computed tomography scan, but the difficulty was encountered due to nonspecific radiologic features of angioleiomyoa. Surgical intervention was performed for precise diagnosis and treatment. The tumors were fed from the STA, with the diagnosis of venous type parotid angioleiomyoma. To our knowledge, there have been only one previous report of angioleiomyoma of the parotid gland fed from STA in the literature. Once parotid tumor is discovered, although rare, the possibility of angioleiomyoma should be considered, and the authors recommend prompt surgical excision for accurate diagnosis and treatment.

Perivascular epithelioid cell tumor (PEComa) of the pterygopalatine fossa

Perivascular epithelioid cell tumors (PEComas) are a rare group of mesenchymal tumors associated with tuberous sclerosis. These tumors are typically treated with resection and rarely recur or exhibit malignant behavior. A 78-year-old woman presented with an incidentally discovered pterygopalatine fossa/retroantral mass. Excisional biopsy was performed and revealed pathology consistent with PEComa. Upon review of the literature, there have been 43 reported cases of PEComa of the head and neck. There is only one previously reported case of PEComa in the skull base, and none reported in the pterygopalatine fossa. Of note, the previously reported case of skull base PEComa involved an aggressive tumor with widespread metastasis. Here, we report the first case of a PEComa of the pterygopalatine fossa/retroantral region, which was treated conservatively. This rare pathology should be considered in the differential diagnosis for atypical skull base tumors.

Angiomyolipoma of the Glabellar Region

Angiomyolipomas are hamartomatous lesions consisting of smooth muscle bundles, thick-walled blood vessels, and mature adipocytes. They are usually found in the kidneys of tuberous sclerosis patients and more rarely in other organs, such as the liver, the oral cavity, the sinonasal tract, the heart, the large intestines, the lungs, and the skin. Cutaneous angiomyolipoma has shown to be very rare and generally occurs at the ends of the digits, the elbows, the ears, and the nose. Herein, we report the first documented case of angiomyolipoma of the glabellar region.

HMB-45 negative angiomyolipoma of the orbit: a case report and review of the literature

BACKGROUND

Angiomyolipoma is a benign mesenchymal tumor composed of variable amounts of smooth muscle, adipose tissue and thick-walled blood vessels, and usually named PEComas (perivascular epithelioid cell tumors). PEComas share overlapping histopathological features with epithelioid cells along a perivascular distribution and characteristic immunohistochemistry with coexpression of myoid and melanocytic markers (HMB-45 /or Melan-A). We report the first case of primary orbital angiomyolipoma with negative melanocytic marker.

CASE PRESENTATION

An 80-year-old Asian woman had a 2-year history of progressive swelling in the left upper eyelid. External examination revealed 3 cm of relative proptosis of the left eye and a palpable mass in the left superonasal orbit. Computed tomographic scan demonstrated a circumscribed, heterogeneous orbital mass. Excision biopsy was done and the histological finding demonstrated the orbital mass was composed of mature adipocytes, intermingled with spindle or oval-shaped cells, and accompanied by thick-walled blood vessels. Immunohistochemically, tumor cells were positive for CD34 and HHF-35, but negative for cytokeratin, HMB-45 and Melan-A. The diagnosis of angiomyolipoma was made. No recurrence was noted at 2-year follow-up.

CONCLUSION

In our case, the HMB-45 negativity may be explained by the rarity of the epithelioid cells, and the HMB-45 positivity is often weaker or absent in spindle cells. Angiomyolipoma, although rare, should be added to the differential diagnosis of space-occupying orbital lesion.

A rare benign parotid gland tumor: angiomyolipoma

Angiomyolipomas are benign neoplasms composed of smooth muscle, vasculature, and mature adipose tissue, which most commonly occur in the kidney and located in the head and neck region. A very rare neoplasm, there are only 3 cases of angiomyolipoma in the parotid gland that have been reported to date. Here, we report a case of a 38-year-old man who had a slow-growing mass in the parotid gland for the past 7 years. The results of a physical examination revealed a rubbery mass that was 2.5 cm in diameter in the below superficial lobe of the left parotid gland. A computed tomographic scan showed a heterogeneous and lobulated nodule with a well-defined margin, which was resected through partial parotidectomy with preservation of the facial nerve. A histologic finding revealed an angiomyolipoma of the parotid gland. In conclusion, angiomyolipoma should be considered in the differential diagnosis of rubbery parotid gland masses.

Time to abandon the term angiomyolipoma for non-PEComatous angiomyomatous (or angiomatous) oral tumors with adipocytes

Angiomyolipoma (AML) is the most common benign mesenchymal neoplasm of the kidneys with well-established clinical and morphological features. The oral and maxillofacial pathology literature contains several examples that identify angiomyomatous proliferations of the oral mucosa that contain an adipocytic component as analogous to classic renal AMLs although they differ significantly in their immunohistochemical phenotype. Herein, through review of the pertinent oral pathology literature and the detailed description of 2 lesions, one an oral angiomyoma with an adipocytic component and the other an apparently hamartomatous angioleiomyomatous proliferation with adipocytes, we provide, in our opinion, a solid argument against the use of the term AML for non-PEComatous oral tumors.

[Angiomyolipoma of the parotid gland]

INTRODUCTION

Angiomyolipoma is a rare benign mesenchymal tumor. It often arises in the kidney and in association with tuberous sclerosis or lymphangioléiomyomatosis. Extrarenal locations have been described, especially in the liver. Only a few cases have been described in the head and neck region and these are usually not associated with tuberous sclerosis or lymphangioléiomyomatosis.

MATERIAL AND METHODS

We report a case of angiomyolipoma located in the parotid gland.

RESULTS

A 43-year-old man consulted for treatment with a slow-growing nodule located in his right parotid gland. Ultrasound examination and magnetic resonance imaging revealed a well-limited lesion. Fine needle aspiration cytology was not suspicious. Partial parotidectomy was performed and the tumor showed the characteristic appearance of angiomyolipoma, with an admixture of fat smooth cells and tortuous thick-walled blood vessels. Genetic analysis showed anomalies on chromosomes 7 and 18.

CONCLUSION

This article discusses the presentation and management associated with this exceptional tumor.

Angiomyolipoma of the larynx: case report

The authors present the report of the first ever case of angiomyolipoma arising in the larynx. The tumor was found in a 61-year-old man and was resected through laryngofissure. Histopathologic examination of the tumor revealed numerous smooth muscle cells, mature adipose tissue and numerous thin and large irregular vessels. Both histological and immunohistochemical findings were typical for tumors of the mucocutaneous angiomyolipoma group.

Nasal angiomyolipoma

Angiomyolipomas (AMLs) are hamartomatous lesions containing smooth muscle, vasculature and mature adipose tissue. AML occurs most frequently in the kidneys, with the liver being the second commonest site of involvement. Other localizations for AML are extremely rare and, to our knowledge, only six cases of AML of the nasal cavity have been reported to date. Our case involved a 52-year-old male who presented with a history of snoring and obstruction of the left nasal cavity. Physical examination revealed a 3-cm polypoid mass in the left nasal cavity, which was excised surgically. Histopathologic examination revealed that the lesion was composed of smooth muscle bundles, mature adipose tissue and blood vessels of different sizes. No epitheloid smooth muscle cells were observed and HMB-45 staining was negative. In conclusion, although nasal AML is a rare lesion, it should be considered in the differential diagnosis of polypoid nasal masses, especially when the mass occurs unilaterally.

[Cervicothoracic angiomyolipoma: an unusual tumor located at a site difficult to reach for surgery]

Angiomyolipoma is an uncommon hamartomatous renal tumor very prone to spontaneous bleeding. However it is possible to find it in extrarenal sites, being the liver the most frequent one. The rest of sites recorded in literature are exceptional. In fact, to our knowledge, this is the first case reported of cervicothoracic settlement of an angiomyolipoma. This rare location, together with its marked tendency to bleed bleeding determinate a complicated diagnoses a difficult surgical approach.

Magnetic Resonance Imaging of Adrenal Angiomyolipoma

Angiomyolipoma is a benign mesenchymal neoplasm that typically occurs in the kidney sporadically or in patients with tuberous sclerosis complex. Extrarenal angiomyolipomas are uncommon, and the liver is the most common extrarenal site. Other sites reported include the bone, colon, heart, lung, parotid gland, skin, spermatic cord, gynecologic regions, and retroperitoneum. A case of an angiomyolipoma involving the right adrenal gland in a 49-year-old female patient with tuberous sclerosis is reported. The magnetic resonance (MR) imaging features are also discussed. Only 2 cases describing adrenal angiomyolipoma were found in the English literature. Neither of these 2 cases was documented in the radiology literature or discussed the MR features of adrenal angiomyolipoma.

Extrarenal retroperitoneal angiomyolipoma: case report and review of the literature

Angiomyolipomas are rare benign tumors that usually occur in the kidneys. Extrarenal angiomyolipomas are extremely uncommon. We describe a case of angiomyolipoma arising in the retroperitoneum that was successfully treated by arterial embolization and surgical excision. The literature on retroperitoneal extrarenal angiomyolipoma and its differential diagnoses is briefly reviewed.

Primary monotypic epithelioid angiomyolipoma of bone

AIMS

Monotypic epithelioid angiomyolipoma is a distinct and definable variant of angiomyolipoma, composed of monomorphous epithelioid cells that show HMB45 immunoreactivity. Angiomyolipoma, including its morphological variants, belongs to the family of perivascular epithelioid cell tumour.

METHODS AND RESULTS

The tumour was examined using immunohistochemical staining and by transmission electron microscopy. Neoplastic cells showed a cytoplasmic granular positivity for HMB45.

CONCLUSIONS

Extrarenal angiomyolipomas are rare and, to the best of our knowledge, this is the first reported case of a primary monotypic epithelioid angiomyolipoma of bone in a patient without evidence of tuberous sclerosis.

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.

Immunohistochemical study of microphthalmia transcription factor and tyrosinase in angiomyolipoma of the kidney, renal cell carcinoma, and renal and retroperitoneal sarcomas: comparative evaluation with traditional diagnostic markers

Angiomyolipoma has a unique immunophenotype with co-expression of muscle-specific actin and melanocytic markers such as HMB-45 and Melan-A. The most recently developed melanocytic markers, microphthalmia transcription factor and tyrosinase, have not been studied in the diagnosis of angiomyolipoma. We tested 29 renal angiomyolipomas (21 classic histology, 4 epithelioid variants, 2 lipomatous variants, and 2 leiomyomatous variants) with an immunohistochemical panel, including microphthalmia transcription factor, tyrosinase, HMB-45, Melan-A, and muscle-specific actin. Results were compared with 15 renal cell carcinomas (9 conventional types, 6 with sarcomatoid change), 2 leiomyosarcomas, 5 liposarcomas, and 1 unclassified high-grade sarcoma. Microphthalmia transcription factor expression was seen in 22 of 29 angiomyolipomas, one renal cell carcinoma, and one well-differentiated liposarcoma (that is, 2 of 23 non-angiomyolipomas; sensitivity 75%, specificity 91%). Tyrosinase expression was seen in 4 of 29 angiomyolipomas and 0 of 23 non-angiomyolipomas (sensitivity 14%, specificity 100%). HMB-45 was positive in 24 of 29 angiomyolipomas and 0 of 23 non-angiomyolipomas (sensitivity 83%, specificity 100%). Melan-A was expressed by 25 of 29 angiomyolipomas and 0 of 23 non-angiomyolipomas (sensitivity 86%, specificity 100%). Muscle-specific actin was expressed by 29 of 29 angiomyolipomas and 2 of 23 non-angiomyolipomas (both leiomyosarcomas; sensitivity 100%, specificity 91% [100% excluding leiomyosarcomas]). Microphthalmia transcription factor showed the most widespread staining in angiomyolipoma (50% of cases staining more than half of the tumor cells) followed by Melan-A (24% of cases staining more than 50%). Only three cases showed positivity for all four melanocytic markers, while in one case each only microphthalmia transcription factor and Melan-A were positive. We conclude that microphthalmia transcription factor, but not tyrosinase immunostaining, has a sensitivity and specificity that rivals those of the established markers, HMB-45 and Melan-A, in the diagnosis of angiomyolipoma. Our data supports the use of a panel in difficult cases that includes antibodies to microphthalmia transcription factor, either Melan-A or HMB-45, and muscle-specific actin to provide the best mix of high sensitivity, high specificity, nuclear and cytoplasmic immunolocalization, and widespread staining of cells within a given tumor.