Unique pulmonary presentation of an angiomyolipoma. Analysis of clinical, radiographic, and histopathologic features

Pulmonary metastases of a renal angiomyolipoma: A case report, with whole-exome sequencing analysis

We present a case of pulmonary metastasis originating from renal angiomyolipoma (AML), as evidenced by whole-exome sequencing (WES) analysis. Although AML predominantly arises in the kidneys, it can emerge in various body parts, making it important to distinguish between multicentric development and metastasis. However, previous studies have not distinguished between these conditions. Our case features an 82-year-old woman with a history of renal AML who presented with multiple, randomly distributed, bilateral pulmonary nodules of varying size and pure fat densities. The patient's condition followed a benign course over 10 years. Through WES, we discovered shared mutations in pulmonary lesions that were absent in the patient's blood, including a pathological mutation in TSC2, suggesting a metastatic origin from renal AML. Knowledge of the pulmonary manifestations of AML and their distinctive imaging findings can help radiologists and clinicians diagnose and manage patients with similar presentations.

Cutaneous Angiomyolipoma-A Distinct Entity That Should Be Separated From Classic Angiomyolipoma: Complete Review of Existing Cases and Defining Fundamental Features

Cutaneous angiomyolipoma is a rare mesenchymal tumor that is demographically, clinically, and immunohistochemically distinct from its renal and extrarenal counterparts. We present a case of cutaneous angiomyolipoma in the right retroauricular area of a 35-year-old male patient and provide a broad systematic review of the literature and the largest compilation of cutaneous angiomyolipomas reported to date. According to the findings presented in this review, we conclude that cutaneous angiomyolipoma should be completely separated from renal and extrarenal angiomyolipomas and therefore be considered a distinct entity in the classification of skin tumors.

Epithelioid angiomyolipoma of the pancreas: A case report and review of the literature

BACKGROUND

Angiomyolipomas (AMLs), belonging to the family of mesenchymal tumors, are considered benign lesions that occur mostly in the kidney or as a part of tuberous sclerosis. Epithelioid AML (EAML) is a rare type of AML that appears to have malignant potential. Extrarenal AMLs usually occur in the liver according to the retrieved literature reports. There have been only two previous reports of monofocal primary AML of the pancreas; however, no cases of primary monotypic EAML of the pancreas have been reported.

CASE SUMMARY

An asymptomatic 59-year-old woman incidentally revealed a tumor during abdominal ultrasound examination. Routine blood tests and physical examination were within normal limits. Abdominal ultrasound revealed a 1.9-cm hypoechogenic mass in the tail of the pancreas, clearly visualized by endoscopic ultrasound. However, contrast-enhanced abdominal computed tomography scans did not demonstrate the lesion. A subsequent gadolinium-enhanced magnetic resonance imaging scan showed that the lesion had some characteristic manifestations. The lesion was initially thought to be a neuroendocrine tumor (asymptomatic PanNET). After surgical resection, histopathology and immunohistochemistry confirmed the diagnosis of EAML. At the 6-mo follow-up, no recurrence, spread, or metastasis was identified on computed tomography or magnetic resonance imaging.

CONCLUSION

The preoperative diagnosis of pancreatic AML is extremely difficult. Imaging techniques are essential for providing valuable morphological features for differential diagnosis.

Coexistence of pulmonary lymphangioleiomyomatosis and pulmonary angiomyolipoma

Background

Lymphangioleiomyomatosis (LAM) and angiomyolipoma are two different, but related rare diseases. To the best of our knowledge, pulmonary LAM and pulmonary angiomyolipoma have not previously been observed in the same patient.

Case presentation

A 38-year-old woman presented with a dry cough and left flank pain. She had a right nephrectomy for renal angiomyolipoma 17 years ago. A magnetic resonance imaging scan demonstrated a round mass in the left kidney. A chest computed tomography scan demonstrated scattered small thin-walled cysts and multifocal round nodules in both lungs. A lung biopsy via video-assisted thoracoscopic surgery revealed that the cysts and nodules were manifestations of LAM and angiomyolipomas, respectively. After sirolimus therapy, the renal angiomyolipoma and metastasized pulmonary angiomyolipomas shrank, but pulmonary cysts were unchanged.

Conclusions

LAM and angiomyolipoma are significantly associated, and may coexist in the lungs in rare cases. Sirolimus is effective for both renal angiomyolipoma and metastasized pulmonary angiomyolipomas.

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.

Differential diagnosis of renal tumours with clear cell histology

Clear cell renal cell carcinoma is the most common malignant renal epithelial tumour and constitutes 90% of cases that metastasise. Nevertheless, it is important to recognise that not all clear cell carcinomas contain a preponderance of clear cells and that other renal tumours with different biologies and sensitivities to systemic therapeutic agents may exhibit clear cell cytology. Close attention to the cytological and growth pattern characteristics will allow us to arrive at the proper diagnosis, sometimes with the aid of immunohistochemistry.

Angiomyolipoma in the lung detected 15 years after a nephrectomy for renal angiomyolipoma

Angiomyolipoma is generally found in the kidney, but is especially rare in the lung. Nine cases of angiomyolipoma in the lung have been reported previously, and in 3 of these patients it was involved with nephrectomy for renal angiomyolipoma. The origination of the tumor was not completely recognized, but lymphangioleiomyomatosis and angiomyolipoma are known to have a common feature. The pathogenesis of angiomyolipoma in the lung has recently been researched in relation with lymphangioleiomyomatosis. We review these case reports of angiomyolipoma in the lung and discuss the clinical features and the generation of these tumors.

Surgical management of a giant thoracic angiomyolipoma

This report describes the surgical management of a tumor that filled the left chest of a 58-year-old man. Histopathologic examination showed that this was an angiomyolipoma, a tumor that most commonly occurs in the kidney. The preoperative evaluation and intraoperative management are presented, along with a brief review of this unusual neoplasm.

Pulmonary angiomyolipoma

Extrarenal angiomyolipoma are benign lesions that have rarely been described in the thorax. We present the clinical, radiographic, and pathologic findings of a pulmonary angiomyolipoma in a 63-year-old woman who had no diagnosis of tuberous sclerosis or lymphangioleiomyomatosis. We believe that this report is one of the first descriptions of angiomyolipoma of the lung.

[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.

Atypical pleomorphic epithelioid angiomyolipoma localized to the pelvis: a case report and review of the literature

AIMS

Angiomyolipoma is the most common mesenchymal tumour of the kidney. It has been reported in several other sites outside the kidney, mainly in the liver. We report the first case of atypical pleomorphic angiomyolipoma in a man, arising from the pouch of Douglas and extending to the entire abdominal cavity.

METHODS

A 17-year-old man underwent a complete resection of a giant abdominopelvic mass. The tissue was formalin fixed and paraffin embedded and 4 micro m thick histological sections were stained with haematoxylin-eosin. Immunohistochemical stains for HMB-45, smooth muscle actin, vimentin, calponin, S100 and desmin were performed. Sections for electron microscopy were also prepared.

RESULTS

Microscopic examination revealed a neoplasm composed of pleomorphic epithelioid cells with atypical features, immunoreactive for HMB-45, MART-1, actin, vimentin and calponin, while S100 protein and desmin stains were negative. Ultrastructurally, the tumour cells showed prominent nucleoli, vacuolated cytoplasm, and some premelanosomes. A diagnosis of atypical pleomorphic epithelioid angiomyolipoma was then made.

CONCLUSIONS

To date five patients with abdominal epithelioid angiomyolipoma have been described in the literature. All were women. Three of the five patients reported developed metastasis, while our patient is still free of disease at 16 months of follow-up. Clear prognostic pathological features have not been identified.

Angiomyolipoma of the liver and lung: a case explained by the presence of perivascular epithelioid cells

We report a case of synchronous hepatic and pulmonary angiomyolipoma not associated with tuberous sclerosis or renal angiomyolipoma. The liver tumor contained tortuous vessels, smooth muscle tissue, and fat. It was partially necrotic and made up of pleomorphic epithelioid smooth muscle cells. Positivity for HMB-45 confirmed the diagnosis of angiomyolipoma. Lung biopsy showed multiple abnormal proliferation of smooth muscle cells exhibiting spindle-shaped or epithelioid morphology. The tumor grew around the vessels, and the cells were positive for HMB-45. The occurrence of this case could be explained by a simultaneous proliferation of perivascular epithelioid cells. To the best of our knowledge, this is the first case of hepatic angiomyolipoma associated with multiple pulmonary angiomyolipomas, mimicking hepatic tumor lung metastases on X-ray examination.

Pulmonary glomus tumour: a case initially diagnosed as carcinoid tumour

Pulmonary glomus tumours are rare lesions, with few cases reported previously. Herein, we present the clinical and pathological features of a case of pulmonary glomus tumour. A 29-year-old female patient presented to our clinic complaining of cough, dyspnoea and left-sided chest pain. Computed tomography (CT) of the thorax revealed a nodular lesion causing obstruction of the left main bronchus. Fibreoptic bronchoscopy demonstrated a polypoid mass occluding the left main bronchus 10 mm distal to the main carina. Bronchoscopic biopsy was interpreted histologically as carcinoid tumour. Bronchotomy plus mass extirpation was performed with left thoracotomy. Microscopically, a tumoral structure composed of uniform cells with a round centrally located nucleolus and narrow eosinophilic cytoplasm was seen. Thin-walled vessels lined with endothelium were interspersed between tumoral structures. The cells were stained chromogranin and cytokeratin negative and strongly vimentin positive. The pathological diagnosis for the thoracotomy specimen was pulmonary glomus tumour. Follow-up chest CT was negative for recurrent tumour and the patient remains free of disease 17 months after surgery.

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.

Trabecular angiomyolipoma mimicking hepatic cell carcinoma

Hepatic angiomyolipomas are rare tumors, especially in comparison with those occurring in the kidney. Nevertheless, it is important to be aware of their existence, especially when occurring in the liver, where they might have different subtypes. Not infrequently they are composed of rather irregular cells with epithelioid appearance. In these cases hepatocellular carcinoma or the possibility of other malignant tumors has to be ruled out, with the aid of numerous immunohistochemical reactions. The authors present a case of a female patient, whose liver lesion was first diagnosed on cytological examination as a hepatocellular carcinoma. Based on the preoperative cytological diagnosis, a large liver lobe resection was performed. Histological examination found an angiomyolipoma of the above-mentioned type, and the final diagnosis was ascertained with the aid of vimentin, smooth muscle actin (SMA), and HMB-45.

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.

Pulmonary and mediastinal glomus tumors--report of five cases including a pulmonary glomangiosarcoma: a clinicopathologic study with literature review

Pulmonary and mediastinal glomus tumors are rare lesions, with four previously reported primary pulmonary cases and three mediastinal cases. The authors report one mediastinal glomus tumor, a locally infiltrative type, and four pulmonary glomus tumors, including the first case of primary pulmonary glomangiosarcoma. These tumors show a variety of clinical and pathologic differences from the more common cutaneous variety, including later age at presentation, larger size, and more frequent atypical/malignant features. Mediastinal and pulmonary glomus tumors both have an average patient age at presentation of 45 years. However, compared with their pulmonary counterparts, mediastinal glomus tumors are less common, more often symptomatic, and are larger (average size, 5.4 cm). Additionally, mediastinal glomus tumors more often demonstrate malignant or atypical features. Pulmonary glomus tumors average 3.3 cm in greatest dimension, with the majority measuring less than 2.5 cm. The pulmonary glomangiosarcoma presented was large, measuring 9.5 cm, and showed increased mitotic count (9 mitoses/10 high-power fields), necrosis, cytologic atypia, and was associated with disseminated disease. Regardless of clinical symptoms, histologic features, and even metastases, the vast majority of all benign and malignant glomus tumors are indolent and cured surgically, with adjuvant therapy needed only for occasional patients with more advanced disease. The four patients with glomus tumors reported are currently alive and free of disease as of last follow up. The patient with the glomangiosarcoma developed widespread metastases and died of disease 68 weeks after initial therapy.

Malignant pigmented clear cell epithelioid tumor of the kidney: clear cell ("sugar") tumor versus malignant melanoma

A 73-year-old woman presented with an hemorrhagic kidney tumor initially interpreted as a renal cell carcinoma (RCC). A retroperitoneal recurrence infiltrating the duodenal wall was made up of clear cells, some of which contained Fontana-Masson positive pigment, immunopositive for HMB-45, S-100 protein, actin, and vimentin. The same immunohistochemical profile was retrospectively reproduced in the kidney tumor, where melanosomes were also found ultrastructurally. Lipomatous differentiation was not observed. There was no history of malignant melanoma (MM), or stigmata of tuberous sclerosis. The patient died of disease 5 years after the initial diagnosis. This neoplasm can be considered as a malignant, pigmented, clear-cell epithelioid variant of angiomyolipoma, or "sugar" tumor of the kidney, with the peculiarity of having a previously unreported component of pigmented cells visible on light microscopy. This finding raises the possibility that the exceptional cases of MM reported in renal parenchyma may be pigmented variants of epithelioid angiomyolipoma rather than true MM.

Pleomorphic Angiomyolipoma of Digestive Tract: A Heretofore Unrecognized Entity

Two cases of pleomorphic angiomyolipoma (AML) composed of bizarre epithelioid smooth muscle cells located in the gastrointestinal tract are reported. One involved the appendix of a 6-year-old girl, and the second the cecum of a 22-year-old woman. In both instances the tumor cells were immunoreactive for HMB-45 and A103. To the best of our knowledge, this peculiar variant of an AML has not previously been recognized in this location. Int J Surg Pathol 8(1):67-72, 2000

Pulmonary angiomyolipoma and multifocal micronodular pneumocyte hyperplasia associated with tuberous sclerosis

A 36-year-old woman with a long-standing diagnosis of tuberous sclerosis was found dead. A yellow-tan 0.4 cm-diameter pulmonary tumor was identified at autopsy which had typical microscopic features of an angiomyolipoma (AML). Immunohistochemical stains showed reactivity for actin, but not HMB-45, Melan-A, and tyrosinase (despite reactivity of the patient's renal AML for HMB-45 and Melan-A), perhaps owing to the small size of the lesion and the sometimes focal nature of the reactivity for these markers. Additional lung nodules proved to be multifocal micronodular pneumocyte hyperplasia. This report highlights the first occurrence of a pulmonary angiomyolipoma in the setting of tuberous sclerosis.

Angiomyolipoma of the parotid gland: a case report

Angiomyolipoma is a hamartomatous process that most frequently occurs as a single lesion or multiple foci in the kidneys of patients affected by tuberous sclerosis. Angiomyolipoma can also arise in extrarenal sites, among which the liver is the most frequently recorded. Only rare cases of angiomyolipoma located in the head and neck region (ear and oral and nasal cavity) have been described. The purpose of the present article is to report a case of angiomyolipoma of the parotid gland. A 68-year-old woman appeared for treatment with a slow-growing nodule located in her right parotid gland. Ultrasound examination revealed a heterogeneous nodule with well-defined margins. The nodule was surgically removed by total parotidectomy and showed the characteristic appearance of angiomyolipoma, with an admixture of fat smooth muscle cells, and tortuous, thick-walled blood vessels. Careful physical examination of the patient failed to reveal features of tuberous sclerosis. Angiomyolipoma should be considered in the differential diagnosis of mesenchymal lesions involving the salivary gland.

Hepatic angiomyolipoma: a clinicopathologic study of 30 cases and delineation of unusual morphologic variants

Hepatic angiomyolipoma (AML) is frequently misdiagnosed. HMB-45 is a promising immunomarker for this tumor that leads to recognition of some AMLs with unusual morphology. The purpose of this collaborative study is to better define the morphologic variations of AML. Thirty AMLs were examined, including four biopsy specimens and two fine-needle aspirates. The diagnosis was confirmed by the presence of HMB-45-positive myoid cells. Almost half the cases were originally misdiagnosed as carcinomas or sarcomas. There was marked female predominance (25:5), and the mean age was 48.7 years (range 29-68). Three patients (10%) had evidence of tuberous sclerosis and all had renal AML. According to the line of differentiation and predominance of tissue components, the tumors was subcategorized into mixed, lipomatous (> or = 70% fat), myomatous (< or = 10% fat), and angiomatous type. The mixed type was the most common (11 resected cases), comprising sheets of epithelioid muscle cells admixed with islands of adipocytes, abnormal vessels, and frequently, hematopoietic cells. Six tumors (including three from biopsy specimens) were heavily fatty and showed predominantly adipocytes with epithelioid and short spindle myoid cells webbed between fat cells. Of 10 myomatous AMLs, five tumors showed a pure sinusoidal trabecular pattern and comprised mainly epithelioid cells. Typically, mature adipocytes were absent or scanty, but fat was seen as fine droplets within cytoplasm or as occasional large globules in sinusoids. Pelioid and inflammatory pseudotumor-like patterns were identified focally. Regarding cellular features of the myoid cells, most of the epithelioid cells were either eosinophilic or clear with spiderweb cell morphology. Three AMLs showed an almost purely oncocytic appearance with scanty fat. Large pleomorphic epithelioid cells existed as small foci. Spindle cells arranged in long fascicles were uncommon. D-PAS-positive globules were common around pelioid areas. Brown pigments with staining characteristics of hemosiderin and/or melanin were noted. In conclusion, we propose HMB-45-positive myoid cells as the defining criterion of hepatic AML, which is a tumor capable of dual myomatous and lipomatous differentiation and melanogenesis. Because of its protean morphologic appearance, recognition of the various variant patterns and cell types is important for a correct diagnosis, assisted by immunohistochemical confirmation with HMB-45. Trabecular and oncocytic cell tumors appear to stand out as distinctive subtypes.

Gastric angiomyolipoma: a previously undescribed cause of upper GI hemorrhage

Angiomyolipomas are rare lesions often arising in the kidney. We describe the first documented case of symptomatic gastric angiomyolipoma.

Angiomyolipomatous hamartoma of the tongue

Extrarenal angiomyolipoma is a rare subtype of benign lipomatous tumor composed of adipose tissue, blood vessels, and smooth muscle. We report a 60-year-old woman who developed an angiomyolipomatous tumor of the tongue and discuss the differential diagnosis along with a review of the literature. The term angiomyolipomatous hamartoma is proposed for the present lesion to distinguish it from classic oral angiomyolipoma.

Cutaneous angiomyolipoma

Extrarenal angiomyolipomas are rare lesions. An angiomyolipoma located on the right ear lobe in a 49-year-old man is reported. Pathologic examination showed a well-circumscribed subcutaneous nodule, 2 cm in diameter. The components of the tumor were confirmed by immunohistochemistry. Reactivity for HMB-45 was negative. A review of the twelve published cases, including the present, reveals that the patients age ranged from 33 to 77 years (mean 53.6), the male/female ratio was 11.1. The tumors were solitary, asymptomatic, noninvasive, located most commonly in acral skin or on the ear. The clinical impression is that of a cyst, a lipoma or a vascular tumor. Signs of tuberous sclerosis were absent in all cases. In contrast to the renal form, the cutaneous angiomyolipoma is a tumor differing in sex predominance, clinical associations, circumscription, solitariness, and HMB-45 immunoreactivity. Distinction from other mesenchymal lesions depends on recognition of traditional histologic criteria.