Extrapulmonary lymphangioleiomyomatosis and lymphangiomatous cysts in tuberous sclerosis complex

Uterine collision tumor (PEComa and endometrioid carcinoma) in a tuberous sclerosis patient: a case report

Perivascular epithelioid cell tumors are very rare mesenchymal neoplasms arising in various locations, such as the female genital tract, kidney, lung, prostate, bladder, pancreas, soft tissues, and bone. They possess a unique immunophenotype, co-expressing myogenic and melanocytic markers; molecular findings include mutations of tuberous sclerosis complex and translocations of transcription factor E3, a member of the microphthalmia transcription factor gene family. We herewith report a uterine collision tumor consisting of a perivascular epithelioid cell tumor and a moderately differentiated endometrial endometrioid carcinoma in a patient with genetically proven tuberous sclerosis; two leiomyomas were also found in contact with the tumor. Although two such cases one with a benign and another with a malignant perivascular epithelioid cell tumor have previously been reported, ours is, to our knowledge, the first reported in a tuberous sclerosis patient.

Sporadic uterine Lymphangioleiomyomatosis (LAM): Report of a unique case arising in the lower uterine segment with short review

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Extrapulmonary lymphangioleiomyomatosis is rare and can be associated with tuberous sclerosis.

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Recognition of lymphangioleiomyomatosis is important for early disease screening and genetic testing.

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Lymphangioleiomyomatosis in lower uterine segment is very rare and can be overlooked.

Perivascular epithelioid cell tumors (PEComa) of the gynecologic tract

PEComas of the female genital tract are rare mesenchymal neoplasms that are most common in the uterus, but also may occur in other gynecologic locations. As they morphologically and immunohistochemically resemble smooth muscle tumors, distinction between the two entities is often challenging, and may be aided by molecular analysis. Thus far, two distinct molecular groups-classic PEComas with TSC mutations and TFE3-translocation associated PEComas with TFE3 fusions have been described. Recognition of the first group is imperative as these patients may benefit from targeted therapy with mTOR inhibitors, if malignant. This review will focus on recognition of the morphologic and immunophenotypic features of PEComas, as well as the role of molecular testing in their diagnosis and treatment, analysis of the different algorithms to predict behavior, and differential diagnosis.

High Mobility Group AT-Hook 2 (HMGA2) Oncogenicity in Mesenchymal and Epithelial Neoplasia

High mobility group AT-hook 2 (HMGA2) has been associated with increased cell proliferation and cell cycle dysregulation, leading to the ontogeny of varied tumor types and their metastatic potentials, a frequently used index of disease prognosis. In this review, we deepen our understanding of HMGA2 pathogenicity by exploring the mechanisms by which HMGA2 misexpression and ectopic expression induces mesenchymal and epithelial tumorigenesis respectively and distinguish the pathogenesis of benign from malignant mesenchymal tumors. Importantly, we highlight the regulatory role of let-7 microRNA family of tumor suppressors in determining HMGA2 misexpression events leading to tumor pathogenesis and focused on possible mechanisms by which HMGA2 could propagate lymphangioleiomyomatosis (LAM), benign mesenchymal tumors of the lungs. Lastly, we discuss potential therapeutic strategies for epithelial and mesenchymal tumorigenesis based on targeting the HMGA2 signaling pathway.

Uterine PEComas: A Morphologic, Immunohistochemical, and Molecular Analysis of 32 Tumors

Uterine perivascular epithelioid cell tumors (PEComas) are rare neoplasms that may show overlapping morphology and immunohistochemistry with uterine smooth muscle tumors. In this study, we evaluated the morphologic, immunohistochemical, and molecular features of 32 PEComas, including 11 with aggressive behavior. Two distinct morphologies were observed: classic (n=30) and those with a lymphangioleiomyomatosis appearance (n=2). In the former, patients ranged from 32 to 77 (mean: 51) years and 13% had tuberous sclerosis. Tumors ranged from 0.2 to 17 (mean: 5.5) cm with 77% arising in the corpus. Epithelioid cells were present in 100% and a spindled component was seen in 37%. Nuclear atypia was low (53%), intermediate (17%), or high (30%). Mitoses ranged from 0 to 36 (mean: 6) and 0 to 133 (mean: 19) per 10 and 50 high-power fields, with atypical mitoses present in 30%. Thin and delicate vessels were noted in 100%, clear/eosinophilic and granular cytoplasm in 93%, stromal hyalinization in 73%, necrosis in 30%, and lymphovascular invasion in 10%. All tumors were positive for HMB-45, cathepsin K, and at least one muscle marker, with most expressing melan-A (77%) and/or MiTF (79%). A PSF-TFE3 fusion was identified in one while another showed a RAD51B-OPHN1 fusion. Follow-up ranged from 2 to 175 (mean: 41) months, with 63% of patients alive and well, 20% dead of disease, 13% alive with disease, and 3% dead from other causes. In the latter group (n=2), patients were 39 and 49 years old, one had tuberous sclerosis, while the other had pulmonary lymphangioleiomyomatosis. Both tumors expressed HMB-45, cathepsin K, and muscle markers, but lacked TFE3 and RAD51B rearrangements. The 2 patients are currently alive and well. Application of gynecologic-specific criteria (≥4 features required for malignancy: size ≥5 cm, high-grade atypia, mitoses >1/50 high-power fields, necrosis, and lymphovascular invasion) for predicting outcome misclassified 36% (4/11) of aggressive tumors; thus, a modified algorithm with a threshold of 3 of these features is recommended to classify a PEComa as malignant.

Less common manifestations in TSC

Tuberous sclerosis complex (TSC) is due to pathogenic variants in TSC1 or TSC2 genes resulting in hyperactivation of the mTOR pathway. Many organ systems can be affected, such as brain, skin, eye, heart, bone, kidney, or lung. Typical lesions of TSC usually are those included as major criteria, including angiofibromas, hypomelanotic macules, tubers, subependymal nodules, angiomyolipomas, cardiac rhabdomyomas, and lymphangioleiomyomatosis. However, there are many other manifestations less frequent and/or less well known, many of them not included as clinical diagnostic criteria that are part of the clinical spectrum of TSC. The focus of this review will be on these less common and less well-known manifestations of TSC. Among the rare manifestations, we will discuss some clinical findings including arteriopathy, arachnoid cysts, lymphatic involvement, chordomas, gynecological, endocrine, and gastrointestinal findings. Among the manifestations that are very frequent but much less well known, we find the sclerotic bone lesions. Although they are very frequent in TSC they have been largely overlooked and not considered diagnostic criteria, mainly because they are asymptomatic. However, it is important to know their typical characteristics to avoid misdiagnosing them as metastasis.

Computed tomography lymphangiography findings in 27 cases of lymphangioleiomyomatosis

Background Lymphangioleiomyomatosis (LAM) is a rare disease involving the bronchi, lymphatic vessels, and veins. However, there are few reports about lymphatic vessel abnormalities associated with LAM. Purpose To evaluate computed tomography (CT) lymphangiography findings in cases of LAM, especially lymphatic vessel abnormalities. Material and Methods Twenty-seven patients with LAM underwent direct lymphangiography (DLG), followed by a post-procedural thoracoabdominal CT examination. Results All 27 patients were diagnosed with LAM, including 25 (93%) with chylothorax, eight (30%) with chyloperitoneum, seven (26%) with chylous fluid in the chest and abdomen, and one (4%) with lower-limb lymphedema. The CT lymphangiography showed that 27/27 (100%) patients presented iliac or retroperitoneal lymphatic vessel dilation; 20/27 (74%) presented thoracic duct outlet obstruction; 9/27 (33%) presented pleural lymph leakage; and 13/27 (48%) presented an abnormal distribution of contrast agent in the contralateral lumbar trunk, 3/27 (11%) in the pulmonary field, 1/27 (4%) in the abdominal cavity, and 4/27 (15%) in the pelvic cavity. Five of the 27 patients (19%) had retroperitoneal lymphangioleiomyomas, with contrast agent accumulation in three cases during CT lymphangiography. Two of the 27 (7%) patients had enlarged lymph nodes in the retroperitoneum. All 27 patients (100%) diagnosed with LAM displayed various lung cysts on thoracic high-resolution CT scans. Conclusion CT lymphangiography findings can be used to diagnose most LAM cases accurately. Moreover, these findings also display the various lymphatic vessel abnormalities associated with LAM.

Minireview: Lymphangioleiomyomatosis (LAM): The "Other" Steroid-Sensitive Cancer

Lymphangioleiomyomatosis (LAM) is a devastating rare lung disease affecting primarily childbearing age women in which tumors consisting of abnormal smooth-muscle-like cells grow within the lungs and progressively lead to loss of pulmonary function. LAM cells metastasize to the lungs, predominantly through the lymphatics; however, the source of the LAM cell is still unknown. LAM cells contain inactivating mutations in genes encoding tuberous sclerosis 1 or 2, proteins that normally limit cell growth through suppression of mammalian target of rapamycin complex 1. As of today, sirolimus (an mammalian target of rapamycin complex 1 inhibitor) is the only treatment, available for LAM patients that is approved by the Food and Drug Administration; however, this drug and others in its class provide stabilization but not remission of LAM. One of the biggest problems in treating LAM is that both the origin of the LAM cells and the mechanism of the sexual dimorphism in LAM are still not understood. LAM cells express estrogen and progesterone receptors, and lung function declines during periods of high circulating estrogen levels. Moreover, numerous basic research studies find that estrogen is a key driving force in LAM cell proliferation, migration, and metastasis. In this review, we highlight recent insights regarding the role of steroid hormones in LAM and discuss possible explanations for the profound female sexual dimorphism of LAM.

Malignant presentation of uterine lymphangioleiomyomatosis

OBJECTIVE

The main aim of this case report was to present the method of diagnosis, management, and the 12-year-follow-up of a patient diagnosed with primary uterine lymphangioleiomyomatosis (LAM).

CASE REPORT

A 47-year-old woman was admitted to the Department of Thoracosurgery due to pulmonary lesions suspected to be metastatic. The potential primary site of the neoplasm was not identified by previous imaging studies and specialist counseling. The patient had a history of total abdominal hysterectomy without ovaries due to a uterine tumor recognized as cellular leiomyoma and left salpingo-oophorectomy due to a solid ovarian tumor also recognized as leiomyoma. She had previously undergone the removal of a left kidney angiomyolipoma. After histopathological examination of the pulmonary lesions and repeated evaluation of the ovarian and uterine tumors, the diagnosis of primary uterine LAM with metastases to the ovary and the lungs was established. Although new metastatic lesions occurred, the patient remained in good condition during the 12-year-follow-up.

CONCLUSION

The history of our patient and review of the literature suggest that although uterine LAM presents malignant features (i.e., metastasis), the disease is long lasting and the patient can be in good condition for a number of years.

Gynecologic Manifestations of Less Commonly Encountered Hereditary Syndromes

This review covers gynecologic manifestations that may occur in rare hereditary syndromes. Recent advances in disorders, such as hereditary leiomyomatosis, renal cell carcinoma syndrome and tuberous sclerosis complex, are discussed as well as lesions that occur in von Hippel-Lindau syndrome, nevoid basal cell carcinoma syndrome, Cowden syndrome, Ollier disease/Maffucci syndrome, and Carney complex. Characteristic clinicopathologic features of each of these syndromes are discussed with an emphasis on the key features that enable pathologists to identify patients at highest risk for these diseases.

PEComa: morphology and genetics of a complex tumor family

Perivascular epithelioid cell tumors, or PEComas, are mesenchymal neoplasms composed of histologically and immunohistochemically distinctive epithelioid or spindle cells, which are immunoreactive for both smooth muscle and melanocytic markers. The cells in PEComas are typically arranged around blood vessels and appear to form the vessel wall, often infiltrating the smooth muscle of small- to medium-sized vessels. Periluminal cells are usually epithelioid and the more peripheral cells are spindle shaped. The cells have small, round to oval nuclei, sometimes with focal nuclear atypia, and clear to eosinophilic cytoplasm, and no counterpart normal cell has been identified. The PEComa "family" now includes angiomyolipoma, pulmonary clear cell "sugar" tumor and lymphangioleiomyomatosis, primary extrapulmonary sugar tumor, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, abdominopelvic sarcoma of perivascular epithelioid cells, and other tumors with similar features at various sites that are simply termed PEComa. Some PEComas occur in patients with tuberous sclerosis complex and share the genetic abnormalities. There is a behavioral spectrum from benign to frankly malignant, and histologic criteria have been proposed for assessing malignant potential. The differential diagnosis can include carcinomas, smooth muscle tumors, other clear cell neoplasms, and adipocytic tumors. PEComas constitute a genetically diverse group that includes neoplasms harboring TFE3 gene rearrangements and those with TSC2 mutations, indicating alternative tumorigenic pathways. Recent advances in therapy of malignant PEComas relate to increased knowledge of specific genetic changes and their effects on metabolic pathways that are susceptible to specific interventions. We review PEComas, emphasizing the diagnostic spectrum and recent immunohistochemical and genetic findings.

Menstrual cycle variation of retroperitoneal lymphangioleiomyomas in lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare disease affecting women, classically involving the lungs. However, extrapulmonary manifestations also occur, including renal angiomyolipomas, retroperitoneal lymphangioleiomyomas and extrathoracic lymphadenopathy. The lung disease is hormone-responsive, but no information exists regarding sex hormone responsiveness of abdominal LAM. Here, we report two women with LAM whose abdominal lymphangioleiomyomas increased in size with hormonal changes of the menstrual cycle. This is the first description of abdominal lymphangioleiomyomas exhibiting hormone responsiveness in LAM. We describe these cases and summarize the literature on abdominal LAM. Menstrual cycle variation should be taken into account when assessing response to therapy, both clinically and in research studies.

Prevalence of uterine and adnexal involvement in pulmonary lymphangioleiomyomatosis: a clinicopathologic study of 10 patients

Lymphangioleiomyomatosis (LAM), a systemic disorder affecting almost exclusively young women, is characterized by the abnormal proliferation of smooth muscle-like cells (LAM cells). LAM can occur either in association with the tuberous sclerosis complex (TSC) (TSC-LAM) or without TSC (sporadic LAM). Recent studies have demonstrated that LAM is a neoplasm arising from constitutive activation of the mammalian target of rapamycin signaling pathway dysregulated by a functional loss of TSC genes, but the primary organ of origin remains unclear. Therefore, we performed histologic and immunohistologic analyses of gynecologic organs in 20 patients, half with and the other half without pulmonary LAM, to determine how often LAM involves the uterus. The results showed that 9 of 10 (90%) patients with pulmonary LAM had uterine LAM lesions. In contrast, no patients without pulmonary LAM had so. All uterine LAM lesions were accompanied by LAM lesions in retroperitoneal or pelvic lymph nodes and LAM cell clusters, each enveloped by a monolayer of vascular endothelial growth factor receptor-3-positive lymphatic endothelial cells. Furthermore, when we compared uterine lesions of TSC-LAM with those of sporadic LAM, proliferation of HMB45-positive epithelioid-shaped LAM cells and infiltrates with a tongue-like growth pattern was more prominent in the former, whereas the extent of lymphangiogenesis within the myometrium was greater in the latter. These results indicate that uterine involvement is a common manifestation of LAM, and, possibly, that the uterus or an adjacent locale in the retroperitoneum or pelvic cavity is the primary site of origin of LAM.

CT and MR imaging findings of lymphangioleiomyomatosis involving the uterus and pelvic cavity

Lymphangioleiomyomatosis (LAM) is a rare idiopathic disease and this is characterized by a proliferation of abnormal smooth muscle cells in the lungs and in the lymphatic system of the thorax and retroperitoneum. The female genital tract is rarely affected by LAM. We report here on the CT and MR imaging findings of extensive LAM involving the uterus and pelvic cavity, and this was seen as multiple cystic uterine and parauterine masses with internal hemorrhage in a young female with tuberous sclerosis complex.

Smooth Muscle Tumors of the Female Genital Tract

Smooth muscle tumors are the most common among mesenchymal tumors in the female genital tract. The vast majority of these neoplasms are clinically benign and easy to diagnose. In contrast, leiomyosarcomas are highly aggressive tumors that may pose considerable diagnostic problems when they display unusual (myxoid or epithelioid) morphology, ambiguous histologic features for malignancy, or an unusual anatomic distribution. Diagnostic criteria for these problematic tumors vary depending on the site and type of histologic differentiation, and are based on a combination of 3 major criteria: (1) moderate to severe cytologic atypia; (2) increased mitotic index; and (3) tumor cell necrosis. Certain benign smooth muscle proliferations may show worrisome histologic features or unusual growth patterns, causing concern for leiomyosarcoma. Furthermore, other tumors, including perivascular epithelioid tumors, may mimic leiomyosarcoma. Careful attention to the clinical and anatomic setting, cytologic and architectural features, and immunohistochemical characteristics are helpful in distinguishing these entities. This article discusses conventional smooth muscle tumors as well as unusual subtypes, with emphasis on the diagnostic criteria and problems in differential diagnosis that arise at each site within the female genital tract.

The pathogenesis and imaging of the tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder characterized by the formation of hamartomatous lesions in multiple organ systems. It is the second most common neurocutaneous syndrome after neurofibromatosis type 1 and has been recognized since the late 1800s. Although the disease has complete penetrance, there is also high phenotypic variability: some patients have obvious signs at birth, while others remain undiagnosed for many years. In addition to skin lesions, TSC patients develop numerous brain lesions, angiomyolipoma (AMLs), lymphangiomyomatosis (LAM) in the lungs, cardiac rhabdomyomas, skeletal lesions, and vascular anomalies, all of which are well seen with medical imaging. Our knowledge of TSC genetics and pathophysiology has expanded dramatically in recent years: two genetic loci were discovered in the 1990s and recent elucidation of TSC's interaction with the mTOR pathway has changed how we manage the disease. Meanwhile, medical imaging is playing an increasingly important role in the diagnosis, management, and treatment of TSC. We provide an update on the genetics and pathophysiology of TSC, review its clinical manifestations, and explore the breadth of imaging features in each organ system, from prenatal detection of cardiac rhabdomyomas to monitoring rapamycin therapy to treatment of AMLs by interventional radiology.

Lymphangioleiomyomatosis and tuberous sclerosis complex

Lymphangioleiomyomatosis (LAM) is a rare multisystemic disease of women of child-bearing age and affects mainly the lungs, promoting cystic destruction of lung parenchyma or leading to abdominal tumor formation (e.g., angiomyolipomas, lymphangioleiomyomas). LAM can arise sporadically or in association with tuberous sclerosis complex (TSC), an autosomal inherited syndrome characterized by hamartoma-like tumor growth and pathologic features that are distinct from manifestations of pulmonary LAM. A substantial body of evidence has now been gathered suggesting that the two diseases share a common genetic origin. TSC is caused by mutations in two genes, TSC1 on chromosome 9q34 and TSC2 on 16p13. Both of these genes are tumor suppressor genes encoding hamartin (TSC1) and tuberin (TSC2). Sporadic LAM is correlated with a mutation in the TSC2 gene and tuberin appears to play a central role in the pathogenesis of the disease. A TSC2 loss or mutation leads to disruption of the tuberin-hamartin heteromer and dysregulation of S6K1 activation leading to aberrant cell proliferation seen in LAM disease. The extremely diverse clinical and radiologic features of the disease and the complex therapeutic approach are reviewed in detail. Although new therapeutic agents have been tested, to date no effective treatment has been proposed and the prognosis of patients with LAM remains poor. As long as newer therapeutic agents do not change this picture, lung transplantation remains the last hope for patients with respiratory failure at the advanced stage of the disease.

Uterine PEComa: appraisal of a controversial and increasingly reported mesenchymal neoplasm

In recent years, a group of tumors that have been designated "perivascular epithelioid cell tumors" (PEComa) have been reported with increasing frequency from a wide variety of anatomic locations. The uterus and retroperitoneum appear to be the most frequent sites of origin for these lesions. PEComas belong to an identically named family of tumors comprised of conventional angiomyolipomas, clear cell sugar tumors, lymphangiomyomatosis and clear cell myomelanocytic tumor of the falciform ligament/ligament teres, and are also known as PEComa-NOS. This article is a primer for clinicians on the most salient clinicopathologic features of uterine PEComas, as most of the debate and discussion have taken place in the pathologic literature. The author appraises in detail the current state of knowledge on PEComas of the uterus based on a review of published data on the 44 previously reported cases, and comments on areas of controversy. The latter are centered predominantly on the significant morphologic and immunophenotypic overlap that exists between uterine PEComa and some smooth muscle tumors of the uterus. The clinicopathologic features of cases reported as epithelioid smooth muscle tumors and cases reported as uterine PEComas are compared and contrasted, and a practical approach to their reporting is proposed.

Renal cystic diseases: a review

This review aims to assist in the categorization of inherited, developmental, and acquired cystic disease of the kidney as well as to provide a pertinent, up-to-date bibliography. The conditions included are autosomal-dominant polycystic kidney disease, autosomal-recessive polycystic kidney disease, unilateral renal cystic disease (localized cystic disease), renal simple cysts, multicystic dysplastic kidney, pluricystic kidney of the multiple malformation syndromes, juvenile nephronophthisis and medullary cystic disease, medullary sponge kidney, primary glomerulocystic kidney disease, and glomerulocystic kidney associated with several systemic disorders mainly of genetic or chromosomal etiology, cystic kidney in tuberous sclerosis, and in von Hippel-Lindau syndrome, cystic nephroma, cystic variant of congenital mesoblastic nephroma, mixed epithelial stromal tumor of the kidney, renal lymphangioma, pyelocalyceal cyst, peripylic cyst and perinephric pseudocyst, acquired renal cystic disease of long-term dialysis, and cystic renal cell carcinoma and sarcoma. Whereas the gross and histologic appearance of some of these conditions may be diagnostic, clinical and sometimes molecular studies may be necessary to define other types.

Perivascular epithelioid cell (PEC) tumors of the uterus: a clinicopathologic study of two cases with aggressive features

We report the clinicopathologic, immunohistochemical and ultrastructural features of two unusual tumors of the uterus composed of spindle and epithelioid cells strongly positive for HMB45. The two patients of 56 and 48 years of age had, respectively, hemoperitoneum and abnormal uterine bleeding. Morphologically, both tumors showed atypia and extensive necrosis. The neoplastic cells express immunohistochemically both melanogenesis (HMB45) and smooth muscle markers (actin). Ultrastructural analysis showed the presence of intracytoplasmic membrane-bound granules. We viewed these neoplasms as perivascular epithelioid cell (PEC) tumors with aggressive features. Follow-up has shown the death of one patient whereas the other is alive without disease 36 months after the surgery. The two patients were evaluated for signs of tuberous sclerosis complex, and findings were negative.

Conservative treatment of a mesenteric lymphangiomyomatosis in an 11-year-old girl with a long follow-up period

The authors report the case of a 11-year-old girl admitted for a mesenteric tumor discovered during an appendicectomy. The abdominal Doppler echography and computed tomography (CT) scan showed a 8 x 6 x 7-cm multinodular mass involved in the mesenterium. Biological markers and iodine 131 meta-iodobenzylguanidine (MIBG) scintigraphy results were normal. Percutaneous biopsies were performed. Pathology results showed perilymphatic proliferation of smooth muscle cells leading to cystic lesions. No sign of malignancy was seen. Laparotomy showed a multinodular fixed mass involved from the root of the mesenterium. The superior mesenteric vessels were encircled by the tumor, which could not be resected completely. Partial resection was performed. The pathology and the immunohistochemical tests confirmed the diagnosis of lymphangiomyomatosis. At 21 years of age, she remains asymptomatic. An echography and CT scan showed the mass remaining unchanged in size and echopattern. Lymphangiomyomatosis (LMA) is thought to affect exclusively women in their reproductive life, and the steroid hormones are supposed to play an essential role in the pathology and in the behavior of this condition. Infantile LMA is exceptional. The patient reported is remarkable for her young age, the location of the tumor, her long history, and her benign course. Because the tumor is supposed to be hormone dependent, the surge of oestrogen in this 21-year-old woman may initiate the extensive form of lymphangiomyomatosis with pulmonary involvement, the prognosis of which is extremely poor.

Inherited interstitial lung disease

This article focuses on recent advances in the identification of genes and genetic polymorphisms that have been implicated in the development of human interstitial lung diseases. It focuses on the inherited mendelian diseases in which pulmonary fibrosis is part of the clinical phenotype and the genetics of familial idiopathic pulmonary fibrosis and other rare inherited interstitial lung diseases. The article also reviews the association studies that have been published to date regarding the genetics of sporadic idiopathic pulmonary fibrosis. The reader is directed to recent reviews on human genetic predisposition of sarcoidosis, environmental-related, drug-related, connective tissue related pulmonary fibrosis, and genetic predisposition of fibrosis in animal models.

Uterine epithelioid leiomyosarcomas with clear cells: reactivity with HMB-45 and the concept of PEComa

In this study, we investigated HMB-45 expression in epithelioid uterine leiomyosarcomas with clear cell areas. From 12 epithelioid leiomyosarcomas, we selected 5 that had: 1) clear cell areas and 2) spindle cell areas that were at least focally positive for desmin and caldesmon. The patients' ages ranged from 47 to 82 years (mean 64 years). Presenting symptoms were uterine bleeding (three), abdominal pain (one), and a pelvic mass (one). There was no history of tuberous sclerosis or lymphangioleiomyomatosis. One patient had stage II disease, one stage III, and three stage IV. All were treated with total abdominal hysterectomy and bilateral salpingo-oophorectomy. Two received radiotherapy, and three were also treated with chemotherapy. The tumors ranged in size from 4 x 3 x 3 cm to 10 x 7 x 6 cm; all had significant cellular atypia, areas of coagulative necrosis, and between 10 and 90 mitoses per 10 high power fields. Vascular invasion was seen in three cases. The epithelioid component varied from 50% to 90% in each case; and the percentage of clear cells was < 1% in one case, 5% in one case, and 10% to 80% in three cases. Smooth muscle actin and desmin were positive in all cases. Four cases were positive for HMB-45 only in the clear cell areas. The tumor with < 1% of clear cells was negative for HMB-45. All were negative for S-100 and c-kit. Three patients died of disease at 9, 30, and 32 months; one patient is alive with progressive disease at 6 months, and one patient (stage II disease) is alive with no evidence of disease at 8 months. Unequivocal uterine epithelioid leiomyosarcomas may have clear cells positive for HMB-45. These tumors might belong to the group of lesion designated as PEComas; however, it is advisable to designate them as uterine leiomyosarcomas. In uterine smooth muscle tumors, some epithelioid cells most likely undergo clear cell changes and become positive for HMB-45. It would be advisable to perform this stain in all epithelioid smooth muscle tumors of the uterus.

Difficulties in the diagnosis of rare immunological diseases manifesting with cystic lung disease and spontaneous pneumothorax: case reports

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease of an unknown cause affecting women of reproductive age and characterised by smooth muscle proliferation along lung lymphatic channels. Pneumothorax develops in up to 80% of patients with LAM and may be the presenting manifestation of the disease. Pneumothorax also precedes or complicates the clinical course of 25% of patients with Langerhans'-cell histiocytosis (LCH, histiocytosis X) pathologically characterised by involved tissue infiltration with large numbers of unusual Langerhans' cells, often organised as granulomas. A 41-year-old female patient was treated twice by simple tube drainage due to left pneumothorax in 1996. She was then diagnosed with chronic obstructive lung disease demonstrating with dyspnea, cough and wheeze. Abnormalities found in the high-resolution computed tomography (HRCT) scanning were characteristic of LAM with thin-walled parenchymal cysts distributed homogeneously in both lungs and with thickening of interlobular septa. A 38-year-old man was hospitalised due to chronic lung failure in the course of LCH characterised by small, poorly limited nodular lesions and thin-walled cysts revealed in HRCT scans. For two years of observation, he has suffered five episodes of right pneumothorax. When diagnosing pneumothorax in the middle-age patients, the possible cause of the disease is LAM or LCH. The use of HRCT scanning may enable good determination of the nature and distribution of parenchymal abnormalities found in the diseases.

Localized retroperitoneal lymphangioleiomyomatosis mimicking malignancy. A case report and review of the literature

Lymphangioleiomyomatosis (lymphangiomyomatosis [LAM]), a rare disease of unknown etiology that is seen only in women usually in the reproductive period, generally presents with features of pulmonary involvement. Extrapulmonary involvement, such as angiomyolipomas and retroperitoneal adenopathy, can occur in up to 75% of cases. It is very rare, however, for patients to present with features of extrapulmonary LAM. We present an unusual, localized case of LAM presenting with neurologic symptoms related to a retroperitoneal mass in a 51-year-old woman. Magnetic resonance imaging showed that the mass involved retroperitoneal lymph nodes, and a clinical diagnosis of atypical sarcoma (possibly from a uterine primary) was made. The mass was resected, and a total abdominal hysterectomy was performed. On pathologic examination, the mass showed classic histologic features of LAM with spread along lymphatic channels in the lymph nodes. Intralymphatic projections simulated lymphatic metastasis; however, the cytologic features were benign. Immunostains revealed the tumor to be positive for smooth muscle actin and desmin, but negative for HMB-45. The uterus was unremarkable, except for a subserosal leiomyoma. Although intratumoral variability for HMB-45 has recently been described, to the best of our knowledge, this is the first documented case of HMB-45-negative, histologically classic LAM. Because of the presence of several atypical features in this case, such as age, location, compressive neurologic presentation, radiologic impression of atypical sarcoma, and HMB-45 negativity, we feel that this case may represent a distinct, as yet uncharacterized variant of LAM.

Endothelial lesions of soft tissues: a review of reactive and neoplastic entities with emphasis on low-grade malignant ("borderline") vascular tumors

Soft tissue proliferations composed of endothelial cells are a heterogeneous group of lesions that can cause diagnostic difficulty. Further complicating the issue is the constantly changing nomenclature of some entities, as well as reclassification of some vascular tumors from the high-grade malignant category to the low-grade malignant or borderline category. Modern ancillary techniques such as immunohistochemistry and cytogenetics have done little to advance our knowledge of these lesions. This review article outlines the most recent classification of endothelial lesions of the skin and soft tissues, with emphasis on the low-grade malignant (borderline) category. In addition, many tumor-like lesions containing an endothelial component are also discussed.

Perivascular epithelioid cell tumor ('PEComa') of the uterus: a subset of HMB-45-positive epithelioid mesenchymal neoplasms with an uncertain relationship to pure smooth muscle tumors

The family of lesions thought to be composed at least in part of perivascular epithelioid cells, characterized as HMB-45-positive epithelioid cells with clear to eosinophilic granular cytoplasm and a propensity for a perivascular distribution, includes some forms of angiomyolipoma and lymphangioleiomyomatosis, as well as clear cell "sugar" tumor (CC-SUGAR). When composed predominantly or exclusively of epithelioid cells, it has been suggested that these lesions be classified as "perivascular epithelioid cell tumors" (PEComa). Four cases of uterine PEComa have been described in the literature, three of which exhibited aggressive behavior. We report the clinical, histologic, and immunohistochemical features of eight more examples of uterine PEComa. Patients ranged in age from 40 to 75 years (mean 54 years). Most patients presented because of abnormal uterine bleeding, and grossly a mass was present in the uterine corpus. Morphologically, the tumors could be divided into two groups (A and B). Group A tumors demonstrated a tongue-like growth pattern similar to that seen in low-grade endometrial stromal sarcoma and were composed of cells that tended to have abundant clear to eosinophilic pale granular cytoplasm, diffuse HMB-45 expression, and focal muscle marker expression. Group B tumors were composed of epithelioid cells with less prominent clear cell features, smaller numbers of which were HMB-45-positive. They also featured extensive muscle marker expression and a lesser degree of the endometrial stromal sarcoma growth pattern seen in group A tumors. Two of the four patients with group B tumors had pelvic lymph nodes involved by lymphangioleiomyomatosis, and one of these patients had the tuberous sclerosis complex. Seven of the eight patients with PEComas were treated by hysterectomy. All eight patients are alive and well, although follow-up of >2 years was available only for two patients. Uterine epithelioid smooth muscle tumors and low-grade endometrial stromal sarcomas were compared with the PEComas. Group A PEComas, group B PEComas, and epithelioid smooth muscle tumors were all parts of a continuous histologic spectrum, with group A PEComa at one end of the spectrum and epithelioid smooth muscle tumors at the other, while group B tumors shared features of both. PEComa was histologically and immunohistochemically distinct from endometrial stromal sarcoma. Our data and a review of the literature indicate that PEComa is a subset of HMB-45-positive epithelioid mesenchymal tumors of the uterus with an uncertain relationship to pure smooth muscle tumors. Although none of the patients in this study experienced recurrence during a short follow-up period, some reported in the literature have had recurrences; consequently, we think uterine PEComa should be considered a tumor of uncertain malignant potential until long-term outcome data for a larger number of patients become available.

Chromosome 16 loss of heterozygosity in tuberous sclerosis and sporadic lymphangiomyomatosis

In previous work we found loss of heterozygosity (LOH) of the wild-type TSC2 allele in the abnormal pulmonary smooth muscle cells and renal angiomyolipoma cells from patients with sporadic pulmonary lymphangiomyomatosis (LAM). Here we report TSC2 LOH in microdissected pulmonary LAM cells from a patient with tuberous sclerosis complex (TSC), demonstrating for the first time that the two-hit tumor suppressor gene model applies to the TSC-associated, as well as sporadic LAM. We also compared the chromosome 16 LOH region between angiomyolipoma and pulmonary LAM from two patients with sporadic LAM. Previously we found that these patients had TSC2 mutations and TSC2 LOH in their angiomyolipomas and pulmonary LAM cells but not in normal lung or kidney cells. This suggests that pulmonary LAM may result from the migration of smooth muscle cells from renal angiomyolipomas to the lung. In this case, one would predict that the angiomyolipoma and LAM cells would have identical LOH patterns. We found that at each chromosome 16 marker, the results were concordant between angiomyolipoma and LAM. This is consistent with a model in which pulmonary LAM cells and angiomyolipoma cells have a common genetic origin.

Association of lymphangioleiomyomatosis (LAM) with endosalpingiosis in the retroperitoneal lymph nodes: report of two cases

We report 2 patients in whom pulmonary lymphangioleiomyomatosis (LAM) affected the retroperitoneal lymph nodes and was associated with endosalpingiosis. These lesions were large, encapsulated masses with multiple cysts containing chylous fluid. Both were characterized by proliferating LAM cells that formed fascicles separated by slit-like channels. Some cysts were lined by ciliated epithelium resembling that of Fallopian tubes. Other cysts were lined either by flattened endothelial cells or by a mixture of these cells and epithelial cells. Many LAM cells gave a positive reaction with HMB-45 antibody. Most LAM cells in fascicles were reactive for alpha-smooth muscle actin and desmin. In 1 patient, many of the epithelial cells and some of the subjacent LAM cells were positive for estrogen and progesterone receptors. In conclusion, immunostaining with HMB-45 antibody and markers for smooth muscle cells can be helpful in the evaluation of problems in the differential diagnosis of lesions of extrapulmonary LAM, particularly those involving the genital system.

The spectrum of mutations in TSC1 and TSC2 in women with tuberous sclerosis and lymphangiomyomatosis

Lymphangiomyomatosis (LAM) is a progressive and often fatal interstitial lung disease characterized by a diffuse proliferation of abnormal smooth muscle cells in the lungs. LAM is of unusual interest biologically because it affects almost exclusively young women. LAM can occur as an isolated disorder (sporadic LAM) or in association with tuberous sclerosis complex (TSC). Because only a minority of women with TSC develops symptomatic LAM, we hypothesized that a relationship might exist between the type of germline TSC1 or TSC2 gene mutation and the risk of developing LAM. We examined all 41 exons of the TSC2 gene and 21 coding exons of the TSC1 gene for mutations in a group of 14 women with both TSC and LAM using single-strand conformation polymorphism analysis. Seven mutations were found in TSC2 and one in TSC1. Of the seven patients with TSC2 mutations, two had the same in-frame exon 40 deletion and one had an exon 41 missense change. We conclude that germline mutations in the extreme carboxy-terminus of tuberin can result in LAM. Further studies will be required to determine whether mutations in exons 40 and 41 are associated with an increased incidence and/or severity of LAM in women with TSC.

Frequent estrogen and progesterone receptor immunoreactivity in renal angiomyolipomas from women with pulmonary lymphangioleiomyomatosis

OBJECTIVE

To determine whether renal angiomyolipomas from women with pulmonary lymphangioleiomyomatosis (LAM) express estrogen receptor (ER) and progesterone receptor (PR).

DESIGN

Retrospective study of archival tissue.

PATIENTS

Twelve women with LAM and angiomyolipomas.

SETTING

Fox Chase Cancer Center.

INTERVENTIONS

ER and PR expression was studied using immunohistochemistry. The hormonal status of the patients at the time of resection of the angiomyolipoma was determined.

RESULTS

Ten of the angiomyolipomas had ER immunoreactivity (83%), and all 12 had PR immunoreactivity (100%). The ER and PR positivity was in the smooth muscle component of the angiomyolipomas only. For five women, pulmonary LAM specimens were also available; two were ER positive (40%), and all five were PR positive (100%). All four angiomyolipomas from women receiving progesterone therapy were ER and PR positive. One tumor from a woman receiving tamoxifen was ER negative and strongly PR positive. One woman was pregnant; her tumor was ER and PR positive.

CONCLUSIONS

ER and PR expression is frequent in renal angiomyolipoma cells from women with LAM. PR was more consistently present than ER in angiomyolipomas and in LAM. Our data suggest that angiomyolipoma growth could be affected by hormonal factors. If the growth of LAM-associated angiomyolipomas slows during hormonal therapy, there are two potential implications for LAM patients: first, angiomyolipoma size could serve as a measurable indication of response to hormonal therapy; and second, surgical removal of angiomyolipomas might be avoided in some cases.

Decline in lung function in lymphangioleiomyomatosis: relation to menopause and progesterone treatment

The progression of lymphangioleiomyomatosis, a rare lung disease in women, is thought to be influenced by hormonal factors. We studied the rate of decline in FEV(1) and carbon monoxide transfer factor (TL(CO)) in a national cohort of patients with lymphangioleiomyomatosis in the United Kingdom and its relation to two factors that might influence the disease, menopausal status and progesterone treatment. We used retrospective data from hospital notes, and of the 50 patients identified 43 had suitable lung function data spanning at least 3 mo. Mean (SD) annual decline in FEV(1) was 118 (142) ml for all patients, and these figures changed little when only data spanning at least 2 and 3 yr were analyzed. There was considerable variation in the rate of decline between subjects, however, and although it tended to be less among postmenopausal women and those receiving progesterone, patient numbers were smaller and the findings were not significant. There was a significant reduction in decline in TL(CO) in premenopausal patients receiving progesterone and in both FEV(1) and TL(CO) after starting progesterone in six patients who had data before and after starting treatment. This study documents the rapid decline in lung function in lymphangioleiomyomatosis, confirms the wide variation between patients, and provides some support for the suggestion that disease progression may be reduced by progesterone. The data provide a basis for designing prospective studies of treatment for lymphangioleiomyomatosis.

Hepatic lymphangiomatosis mimicking polycystic liver disease

Hepatic lymphangiomatosis is a rare disorder characterized by cystic dilatation of the lymphatic vessels in the hepatic parenchyma. It can occur in the liver alone, in the liver and spleen, or in multiple organs. Clinically, diagnosis can be difficult because of the rarity and protean manifestations of this disorder. We describe a 53-year-old woman with hepatic lymphangiomatosis in whom polycystic liver disease had been previously diagnosed. In addition, we review 12 cases of hepatic, splenic, and hepatosplenic lymphangiomatosis with or without systemic lymphangiomatosis and discuss the differential diagnosis.

Utility of fine-needle aspiration in the diagnosis of recurrent pulmonary lymphangioleiomyomatosis: a case report

Pulmonary lymphangioleiomyomatosis (PLAM) is a rare disease of undetermined cause that almost exclusively occurs in women of child-bearing age and is characterized by distinct clinical, radiologic, and pathologic findings. PLAM is usually fatal unless treated with hormonal manipulation or lung transplantation. Primary diagnosis usually requires open lung biopsy to demonstrate the characteristic hamartomatous smooth muscle proliferation. To date, cytologic diagnosis of LAM has been limited to an ancillary role. Herein, we report the diagnosis of this neoplasm in a recurrence in an abdominal lymph node using fine-needle aspiration.

Evidence that lymphangiomyomatosis is caused by TSC2 mutations: chromosome 16p13 loss of heterozygosity in angiomyolipomas and lymph nodes from women with lymphangiomyomatosis

Lymphangiomyomatosis (LAM) is a rare disease, of unknown etiology, affecting women almost exclusively. Lung transplantation is the only consistently effective therapy for LAM. Microscopically, LAM consists of a diffuse proliferation of smooth muscle cells. LAM can occur without evidence of other disease (referred to as "sporadic LAM") or in association with tuberous sclerosis complex (TSC). TSC is an autosomal dominant tumor suppressor gene syndrome characterized by seizures, mental retardation, and tumors in the brain, heart, skin, and kidney. Renal angiomyolipomas occur in approximately 50% of sporadic LAM patients and in 70% of TSC patients. Loss of heterozygosity (LOH) in the chromosomal region for the TSC2 gene occurs in 60% of TSC-associated angiomyolipomas. Because of the similar pulmonary and renal manifestations of TSC and sporadic LAM, we hypothesized that LAM and TSC have a common genetic basis. We analyzed renal angiomyolipomas, from 13 women with sporadic LAM, for LOH in the regions of the TSC1 (chromosome 9q34) and TSC2 (chromosome 16p13) genes. TSC2 LOH was detected in seven (54%) of the angiomyolipomas. We also found TSC2 LOH in four lymph nodes from a woman with retroperitoneal LAM. No TSC1 LOH was found. Our findings indicate that the TSC2 gene may be involved in the pathogenesis of sporadic LAM. However, genetic transmission of LAM has not been reported. Women with LAM may have low-penetrance germ-line TSC2 mutations, or they may be mosaic, with TSC2 mutations in the lung and the kidney but not in other organs.

Immunohistochemical study of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in pulmonary lymphangioleiomyomatosis (LAM)

To evaluate the role of matrix metalloproteinases (MMPs) and their specific tissue inhibitors (TIMPs) in the pathogenesis of the structural damage and cystic lesions found in pulmonary lymphangioleiomyomatosis (LAM), immunohistochemical studies were made of the localization of MMP-1, MMP-2, MMP-3, MMP-9, TIMP-1, TIMP-2, HMB-45, and type IV collagen in sections of lung biopsy specimens from four patients with this disorder. These studies showed increased immunoreactivity compared with that in normal bronchiolar and vascular smooth muscle cells, of MMP-2 and, to a lesser extent, MMP-9 and MMP-1 in the LAM cells. MMP-2 was also localized in some elastic fibers and in the basement membranes of LAM cells and overlying epithelial cells. The basement membranes in both of these sites often showed colocalization of MMP-2 and type IV collagen. Some epithelial basement membranes showing this colocalization were disrupted. These changes were not accompanied by increased immunoreactivity for TIMPs. Taken together with previous observations showing structural damage to elastic fibers and collagen fibrils, and with the absence of demonstrable neutrophil or pancreatic types of elastase, these findings suggest that MMP-2 and MMP-9 (both of which can degrade elastin as well as collagens) are responsible for the connective tissue destruction and cyst formation in LAM.