Glomangiosarcoma in a glomus tumor. An immunohistochemical and ultrastructural study

Malignant glomus tumor of the foot. Case report

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Malignant glomus tumor is exceedingly rare.

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Diagnosis is based on the histopathological examination.

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The group of glomangiosarcomas arising de novo considered the most aggressive.

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Wide local excision remains the treatment of choice.

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These tumors had high potential risk of metastasis.

Introduction and importance

Glomangiosarcoma or is an extremely rare tumor. Few cases are published in the literature.

Case presentation

We present a rare case of 64-year-old female patient presented small reddish subcutaneous nodules on the sole of the foot. Surgical resection revealed malignant glomus, the evolution was marked by an infiltrating local recurrence leading to amputation, without notable metastases after six months.

Clinical discussion

Malignant glomus tumor exhibit unusual characteristics, notably deep localization, large size and infiltration, mitotic activity, nuclear pleomorphism and mitonecrosis. The wide excision and possible amputation for infiltrating local type unresecable was the adequate treatment.

Conclusion

Glomangiosarcoma arinsing de novo are exceedingly rare and must be considered the most aggressive and with high potential risk of metastasis.

Glomus tumour of the fourth toe: case discussion and review of literature

This is a case report with literature review and discussion of current diagnostic studies and management of a rare case of glomus tumour in the fourth toe of a 36-year-old male patient.

Cutaneous malignant glomus tumours: applicability of currently established malignancy criteria for tumours occurring in the skin

Glomus tumours (GTs) have traditionally been classified into benign GTs, GTs with uncertain malignant potential and malignant GTs, based on a combination of criteria such as size of the tumour, degree of nuclear atypia and the level of mitotic activity. Several of the proposed grading criteria are difficult, or even impossible to apply for GTs occurring in the skin. The aim of the study was to analyse the applicability of the currently established GT malignancy criteria for tumours occurring in the skin and to establish their prognostic significance. A total of 25 benign cutaneous GTs, 11 new cutaneous malignant GTs and 36 cutaneous malignant GTs previously published in the literature were studied. We analysed the following clinicopathological features and correlated them with disease outcome: age, sex, site, size, depth of invasion, degree of nuclear atypia, mitotic activity, growth pattern, vascular invasion, spindle-cell morphology and tumoural necrosis. Of all the clinicopathological parameters analysed, only tumoural necrosis was found by univariate analysis (p = 0.001) to be associated with adverse biological behaviour, and none by multivariate analysis. Multivariate statistical analysis failed to detect any clinicopathological features predictive of the disease outcome (e.g., local recurrence, development of metastatic spread and/or death of disease) in cutaneous malignant GTs. Furthermore, the currently established malignancy criteria for cutaneous GTs can be difficult to apply, mainly due to their smaller size. Likewise, counting mitotic activity per 50 high power fields can often not be accomplished in GTs occurring at superficial locations. Complete excision of these tumours coupled with long-term follow-up is the mainstay of treatment for cutaneous malignant GTs. The results of our study also suggest that cutaneous malignant GTs follow a more indolent clinical course than their deep soft tissue counterparts.

BRAF V600E Mutations Occur in a Subset of Glomus Tumors, and Are Associated With Malignant Histologic Characteristics

Glomus tumors are rare mesenchymal neoplasms with a phenotype akin to the modified smooth muscle cells of the glomus body. Most are benign, but rare examples show malignant histologic characteristics and aggressive behavior. We recently encountered a malignant glomus tumor with BRAF V600E mutation. We sought to study a large cohort for this mutation, with particular attention to associated malignant histologic characteristics. Tumors were classified based on WHO criteria as benign, uncertain malignant potential (glomus tumors of uncertain malignant potential-GT-UMP), or malignant. Tumors were screened for BRAF V600E by immunohistochemistry, and positive staining was evaluated further by Sanger sequencing. A total of 102 glomus tumors were included and classified as benign (57, 56%), GT-UMP (15, 15%) and malignant (30, 29%). Tumors occurred in patients aged 8 to 89.9 years (median: 50.2), without sex predilection (55% men). Most occurred in the superficial soft tissue (84%) and upper extremities (55%). Six of 95 tested cases had BRAF V600E mutation (6%), including 0 of 57 benign tumors, 3 of 14 GT-UMP (21%), and 3 of 24 malignant tumors (12%). Follow-up was obtained for 59 cases (median: 75.7 mo, range: 7.8 to 268.5). Three of 11 malignant tumors (27%) had progressive disease: 1 with metastasis to brain and heart, 1 with enlarging residual disease, and 1 with recurrence. Two of 4 GT-UMP (50%) had progressive disease: 1 with metastasis to lung, and 1 with local recurrence (50%). Three of 44 benign tumors (7%) had local recurrence. Two of 5 patients with BRAF V600E had progression, including 1 GT-UMP with local recurrence and 1 malignant tumor with enlarging residual disease. In summary, BRAF V600E mutation was detected in 6% of glomus tumors, all of which were malignant or GT-UMP. This mutation may be associated with a malignant phenotype, although study of additional cases is needed. In patients with progressive disease, BRAF could be a promising therapeutic target.

Glomangiosarcoma Arising from a Prior Biopsy Site

Glomangiosarcoma represents a rare malignant variant of the benign glomus tumor that typically presents as a tender, slowly growing nodule with a predilection for the lower extremities. Unlike their benign counterparts, glomangiosarcomas may display aggressive characteristics such as large size, local invasion, and a tendency to recur after excision. Although wide local excision remains the treatment of choice, rare cases of systemic metastasis have been previously reported. We present a case of glomangiosarcoma arising at a prior biopsy site after excision of an unknown soft tissue lesion.

Glomus Tumor: Twenty-Year Experience and Literature Review

Glomus tumors are rare, usually benign, vascular hamartomas consisting cells resembling the smooth muscle cells of the normal glomus body. They can be solitary or multiple, whereas solitary tumors are majorly located on the digits. Digital glomus tumors most commonly appear in subungual region and show a strong female predominance. There are several classical symptoms, clinical tests, and imaging tools, such as X-ray, magnetic resonance imaging, and ultrasonography, which can provide good accuracy for clinical diagnosis. However, misdiagnosis and delayed diagnosis are still commonly observed because primary physicians are unfamiliar with classical symptoms and clinical tests. Complete surgical excision often can result in complete relief of symptoms. Recurrence is largely caused by incomplete excision, but repeated image study is recommended to rule out new or malignant lesions. This series is a retrospective review of 50 cases with glomus tumors managed at our institute. We aim to review the key aspects of glomus tumor and provide a simple guideline for earlier diagnosis and treatment.

Glomus tumour of the elbow: a case of mistaken identity

Glomus tumours are small vascular tumours that are usually benign and rarely occur. However, atypical locations of these tumours can lead to misdiagnosis, particularly where the lesion is rarely reported. We report a case of glomus tumour located on the posterior aspect of the elbow, which was mistaken for, and treated as the commonly diagnosed, olecranon bursitis for several years. With worsening symptoms, mainly pain, pinpoint tenderness and hypersensitivity, the patient was referred for a further opinion, and the lesion was diagnosed as a glomus tumour following complete excision under anaesthesia. This present case highlights the importance in considering this rare entity in the differential diagnosis of posterior elbow swelling and pain. Furthermore, this report provides a review of the literature and identifies the need for early specialist referral to confirm diagnosis, alleviate patient symptoms and improve function.

The association between glomus tumors and neurofibromatosis

PURPOSE

To determine whether an epidemiologic association exists between glomus tumors and neurofibromatosis.

METHODS

Using a pathology database, we established a study cohort consisting of all patients who had undergone excision of a glomus tumor of the hand between 1995 and 2010. We created a control cohort by randomly selecting 200 patients who had undergone excision of a ganglion cyst over the same period. We reviewed medical records for each cohort to identify patients with a diagnosis of neurofibromatosis. We calculated the odds ratio was calculated and performed Fisher's exact test to determine the significance of the association.

RESULTS

We identified 21 patients with glomus tumors of the hand. Six of these patients carried the diagnosis of neurofibromatosis (29%). In contrast, no patients in the control group carried the diagnosis of neurofibromatosis. The odds ratio for a diagnosis of neurofibromatosis in association with a glomus tumor compared with controls was 168:1.

CONCLUSIONS

This study provides evidence of a strong epidemiologic association between glomus tumors and neurofibromatosis. Glomus tumor should be included in the differential diagnosis in neurofibromatosis patients who present with a painful lesion of the hand or finger.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Vascular and perivascular lesions of skin and soft tissues in children and adolescents

Vascular anomalies in children and adolescents are the most common soft tissue lesions and include reactive, malformative, and neoplastic tumefactions, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic complexity and recent changes in classification systems, some of which are based on clinical features and others on pathologic findings. In recent decades, there have been significant advances in clinical diagnosis, development of new therapies, and a better understanding of the genetic aspects of vascular biology and syndromes that include unusual vascular proliferations. Most vascular lesions in children and adolescents are benign, although the intermediate locally aggressive and intermediate rarely metastasizing neoplasms are important to distinguish from benign and malignant mimics. Morphologic recognition of a vasoproliferative lesion is straightforward in most instances, and conventional morphology remains the cornerstone for a specific diagnosis. However, pathologic examination is enhanced by adjunctive techniques, especially immunohistochemistry to characterize the type of vessels involved. Multifocality may cause some uncertainty regarding the assignment of "benign" or "malignant." However, increased interest in vascular anomalies, clinical expertise, and imaging technology have contributed greatly to our understanding of these disorders to the extent that in most vascular malformations and in many tumors, a diagnosis is made clinically and biopsy is not required for diagnosis. The importance of close collaboration between the clinical team and the pathologist cannot be overemphasized. For some lesions, a diagnosis is not possible from evaluation of histopathology alone, and in a subset of these, a specific diagnosis may not be possible even after all assembled data have been reviewed. In such instances, a consensus diagnosis in conjunction with clinical colleagues guides therapy. The purpose of this review is to delineate the clinicopathologic features of vascular lesions in children and adolescents with an emphasis on their unique aspects, use of diagnostic adjuncts, and differential diagnosis.

Glomangiosarcoma in the shoulder of a 51-year-old man

Glomangiosarcoma is a very rare type of soft tissue neoplasm. Here we report such a case in the shoulder of a 51-year-old man.

Malignant Glomus Tumor of the Leg Developed in the Context of a Superficial Typical Glomus Tumor

A 41-year-old man presented with a 2-cm painful subcutaneous nodule in his right leg, which had been present for more than 10 years and was recently enlarging. Histologically, the tumor was composed of sheets and nests of cells with variable cytomorphology, including typical round/ovoid glomus cells with clear cytoplasm and well-defined borders, small cells, and spindle cells. Numerous medium to large vessels were present. Nodules with moderate to high cellularity, nuclear atypia, and frequent mitotic figures (42 per 50 high-power fields) were noted. Immunohistochemistry showed cytoplasmic and membranous expression of smooth-muscle actin, vimentin, and membranous expression of type IV collagen. Whereas superficiality, dimensions, and long-term follow-up may suggest classification as a symplastic or uncertain potential glomus tumor (GT), histological features and immunoprofile are indicative of malignant nodules developed in a typical GT. The follow-up has been negative for recurrence/metastases. A search of the literature revealed 17 cases of malignant GTs between 1995 and 2010, all fatal, of which 10 had skin as the primary site.

Malignant glomus tumour: a case report and review of the literature

Purpose: Glomus tumours are characteristically benign solitary tumours. At our knowledge, about 23 reports are present in literature regarding the malignant counterpart, but only a minority developed metastases. We describe a locally aggressive glomus tumour with lymphnode metastasis.

Patient: The patient was a 40 year-old man presenting a 1.5-cm lesion on the right wrist incompletely excised and a recurrent tumour, 4 × 2 cm in size, removed after 9 months, for which he received radiotherapy. After 2 years he developed an axillary lymphnode metastasis.

Results: Histologically, both tumours (primary and metastasis) were similar. There were sheets and nests of uniform small cells with scant eosinophilic cytoplasm and round to polygonal nuclei; there was some degree of pleomorphism and the mitotic index was high (up to 18 m/10 HPF). The tumour cells were positive for vimentin and smooth muscle actin, but negative for desmin, NSE, Factor VIII, chromogranin, cytokeratin. Remarkably, in the primary, the cells strongly expressed p53 (70%) and MIB-1 (35%).

Discussions: In many reported malignant cases, the histology of the tumour cells suggested that they were malignant, yet the clinical course has been benign. Carefully reviewing the literature, it seems that actually we have enough histological criteria to identify the cases with biological adverse outcome. Those unfortunate cases behave as high grade sarcomas and therefore may deserve an aggressive therapeutic treatment.

Diagnosis and management of glomus tumors of the hand

AIM AND BACKGROUND

Glomus tumors are hamartomas that account for 1% to 5% of all soft tissue tumors of the hand. These tumors are usually benign. However, malignant degeneration can sometimes occur. They are usually characterized clinically by paroxysmal pain. Herein, we present our experience with 8 patients diagnosed with glomus tumors treated within the past 10 years.

MATERIALS AND METHODS

Eight patients who were diagnosed with glomus tumor of the hand were treated. Excruciating pain upon palpating the tumor was present in all the patients. Imaging studies such as magnetic resonance imaging were obtained but were only marginally helpful in locating and defining the surface topography for tumor resection. Meticulous dissection in a bloodless field and use of an operating microscope from the start of the operation were used for complete removal.

RESULTS

Complete excision of the tumor with free margins was confirmed in all 8 cases. However, 1 of the patients had recurrence of the tumor, which presented 4 weeks postoperatively. No other recurrence was observed during the follow-up period (1 to 10 y). The postoperative course in all patients was uneventful except for deformed fingernail formation in 3 of the patients.

CONCLUSIONS

Glomus tumor is a rare disease; we encountered only 0.26% cases in our patients (3014 patients referring for hand surgery) during a 10-year period. Imaging studies are not very helpful. Preoperative marking of the maximum point of pain helps the surgeon somewhat to locate the tumor clinically. We believe that a bloodless operation field and magnification are essential prerequisites for successful surgery. We also note that pain alleviation and no pain recurrence 2 months after surgery clinically signify a cure. The possible development of permanent nail deformity should be anticipated and must be discussed with the patient preoperatively.

Glomus tumor

Glomus tumor is a benign mesenchymal neoplasm comprising less than 2% of soft tissue tumors. It is composed of cells resembling modified smooth muscle cells of the normal glomus body. The glomus body, a thermoregulator, is a specialized form of arteriovenous anastomosis localized in dermal and precoccygeal soft tissue. Although glomus tumors are rare neoplasms, clinical misdiagnosis of many of these lesions as hemangiomas or venous malformations makes an accurate assessment of their actual prevalence difficult. A malignant counterpart of this lesion exists but is extremely rare.

Extradigital glomus tumors: a 20-year experience

OBJECTIVE

To review a large series of extradigital glomus tumors in order to gain a better understanding of their presentation and provide guidelines to aid in their diagnosis and treatment.

PATIENTS AND METHODS

We performed a retrospective review of all extradigital glomus tumors seen at our institution during a 20-year period (1985-2005) to document the incidence of the classic triad of symptoms, the duration of symptoms, the contribution of imaging to making a definitive diagnosis, and the effectiveness of treatment.

RESULTS

Fifty-six different patients with extradigital glomus tumors presented as follows: glomus tumors in the hand (3), wrist (4), forearm (11), elbow (4), arm (4), shoulder (2), buttock (1), thigh (5), knee (10), leg (3), ankle (2), foot (2), back (1), nose (1), cheek (1), ear lobe (1), and trachea (1). Forty-eight patients presented with pain and localized tenderness, but only 1 patient presented with cold Intolerance. The average duration of symptoms was greater than 7 years, with most patients being evaluated previously and having their conditions misdiagnosed. Magnetic resonance imaging proved to be the most useful modality for localization of these lesions. Surgical resection was the definitive treatment and generally provided immediate and sustained pain relief.

CONCLUSIONS

Extradigital glomus tumors are not a rare subgroup of glomus tumors. Treatment outcomes are excellent, but misdiagnosis and delayed diagnosis are common. Improved guidelines regarding symptoms and diagnosis of these neoplasms may reduce the morbidity, ensuing chronic pain, and psychiatric consequences of delayed diagnosis or misdiagnosis.

Glomangiosarcoma of the hypothenar eminence: a case report

Glomangiosarcoma is an exceptionally rare soft tissue tumor. It tends to appear as a painful nodule located in the subcutaneous tissue. There are only two cases described on the hand before instead of the benign glomus tumor is usually located at this level. Histochemically the glomangiosarcoma shows features that remind a benign glomus tumor, except for the malignant glomus tumor arising de novo. This neoplasm is considered a low grade malignant tumor with tendency to local recurrence, though metastasis have been reported. We report the case of a 36 year-old -woman with a glomangiosarcoma in a glomus tumor in the hypotenar eminence. The treatment was a local complete excision and there was no signs of recurrence after 18 months.

Malignant Glomus Tumor

Malignant glomus tumor (MGT) is a rare, recently described neoplasm that recapitulates the appearance of the modified smooth cells of the normal glomus body. We report a case of MGT of the hand of a 48-year-old woman. Magnetic resonance imaging (MRI) showed a 2.8-cm, well circumscribed, enhancing mass on the volar aspect of the thenar region of the right hand in immediate continuity with the ulnar artery and nerve. Computed tomography scan (CT-Scan) of the chest was normal. Histologic evaluation revealed a multilobular lesion with prominent branching capillary vasculature and perivascular arrangement of sheets of tumor cells. The tumor cells were round, relatively uniform in size with distinct cell borders and perinuclear cytoplasmic clearing. They were of intermediate to high nuclear grade and showed significant mitotic activity. A wide local excision with negative margins was performed. Multiple lung metastases were evident at 8-month follow-up. To date, forty-five cases of MGT of skin and soft issue have been reported in the literature. Twelve of the forty-five cases developed metastasis. In this report, we emphasize the differential diagnosis of MGT in the skin and deep soft tissue.

Vascular tumors of the skin: A selective review

Cutaneous vascular proliferations are a vast and complex spectrum. Many appear as hamartomas in infancy; others are acquired neoplasms. Some vascular proliferations are hyperplastic in nature, although they mimic hemangiomas, i.e., neoplasms. The vast majority of the vascular lesions are hemangiomas. Between the hemangiomas and frankly angiosarcomas, there is a group of neoplasms that are angiosarcomas, albeit ones of low grade histologically and, probably, biologically. The term "hemangioendothelioma" has been created to encompass these neoplasms. Vascular proliferations are, fundamentally, composed of endothelial cells. Some hemangiomas, however, contain also abundant pericytic, smooth muscle, or interstitial components, or a combination of them. These heterogeneous cellular components are present usually in hemangiomas. Some of the newly described vascular proliferations, however, are difficult to differentiate from some of the angiosarcomas. Others are markers, occasionally, of serious conditions such as Fabry's Disease (angiokeratoma) and POEM's syndrome (glomeruloid hemangioma). Kaposi's sarcoma continues to be an enigma. The demonstration of Herpes virus 8 in this condition raises doubt about its neoplastic nature. The demonstration of endothelial differentiation of its nodular lesions is tenuous and its true nature remains unresolved. While physicians have known about post-mastectomy angiosarcomas from the origin of the radical mastectomy, a new group of unusual vascular proliferations of the mammary skin are being defined. These lesions arise in the setting of breast-conserving surgical treatment with adjuvant radiation therapy. The incubation period is usually 3 to 5 years, in contrast with the 10, or more, in classical cases of post-mastectomy angiosarcoma. These lesions usually are subtle, both clinically and histologically, in contrast with the "classical," dramatic presentation of mammary angiosarcoma. The spectrum of findings ranges from "simple" lymphangiectasia-like vascular proliferations to unequivocal angiosarcomas. The pathogenesis of these lesions remains a mystery. There are very few clues that allow one to separate hemangiomas from angiosarcomas. The presence of heterologous cellular elements and, particularly, well-developed smooth muscle components tends to favor a hemangioma. Similarly, the presence of thrombosis usually supports hemangioma. Nevertheless, there are no unequivocal or reliable individual diagnostic criteria. A thorough knowledge of the different conditions and their differential diagnoses eventually leads to the proper diagnosis in most cases.

Glomangiosarcoma of the hand: a case report and review of the literature

Glomangiosarcomas, or malignant glomus tumors, are very rare, cutaneous, soft tissue tumors. Despite having histologic features of malignancy, these tumors usually do not metastasize. We describe a 74-year-old woman with a glomangiosarcoma on her hand and review the literature. The woman presented with a five month history of a painful mass on the right palm. An excisional biopsy of the mass was undertaken. Histologically, the tumor was composed of uniform, round cells and numerous vascular components. The tumor cells were pleomorphic and had large nucleoli. Frequent mitotic figures were identified. Immunohistochemical stains showed strong positivity for vimentin and weak, focal positivity for smooth muscle actin. Ultrastructurally, the tumor cells were characterized by pinocytic vesicles, well formed basal lamina, and scattered junctional complex of the plasma membrane.

Multiple glomus tumors: recognition and diagnosis

BACKGROUND

Glomus tumor is a benign neoplasm of uncommon occurrence in daily practice, more frequently observed as a single painful lesion, at the distal phalanges of the fingers. Multiple presentation is very rare, with fewer than 200 reports, usually presenting as small angiomatous lesions with discrete pain.

OBJECTIVES

The study's objective was to analyze the epidemiologic, clinical, therapeutic, and histopathologic aspects in a series of six cases of multiple glomus tumors.

RESULTS

All patients were men, between 12-45 years of age. The tumor was congenital or appeared between 3-25 years of age. The clinical picture oscillated between three to 10 lesions, as macules, nodules, or tumors, with colors varying from bluish, brown-bluish, violet, to normochromic. The lesions were detected in the trunk and one or more members, not affecting the head, hands, and feet. Pain was discrete or absent. Incisional biopsy for histopathologic evaluation with the hematoxylin-eosin staining confirmed the diagnosis of glomus tumor in all cases. It showed the characteristic glomus cells and vascular spaces. The complete excision of the tumorous plaque was performed in one patient and a complex corrective procedure is still to be performed for one aberrant tumor in another case. The other patients received advice about their disease and were asked to periodically return.

CONCLUSION

Because this is a very uncommon illness, the present series allowed the demonstration of the wide variety of epidemiologic and clinical aspects described in the literature, with the presentation of elements that may improve its recognition and diagnosis.

Sinonasal haemangiopericytoma-like tumour: a sinonasal glomus tumour or a haemangiopericytoma?

AIMS

Sinonasal haemangiopericytoma-like tumour is controversial with regard to its nosologic nature. This study aims to investigate its relationship with glomus tumour and haemangiopericytoma.

METHODS AND RESULTS

Six cases of sinonasal haemangiopericytoma-like tumours identified in our files were reviewed for clinicopathological features, and compared with five cases each of soft tissue glomus tumour and meningeal haemangiopericytoma. Immunohistochemical studies for muscle-specific actin, smooth muscle actin, desmin and CD34 were performed. Sinonasal haemangiopericytoma-like tumour demonstrated a uniform histological appearance with bland-looking short, spindly cells forming sheets and short fascicles. The tumour cells were interspersed with slit-like, round and ectatic blood vessels. Actin immunoreactivity was demonstrated in all six cases, although occasionally patchy. The histological appearance and immunohistochemical phenotype of sinonasal haemangiopericytoma-like tumour were very similar to and focally indistinguishable from glomus tumour. Meningeal haemangiopericytoma, in contrast, was characterized by high tumour cellularity, random nuclear orientation, presence of staghorn vasculature and lack of immunohistochemical evidence of myogenic differentiation.

CONCLUSIONS

We conclude that sinonasal haemangiopericytoma-like tumour is biologically close to or identical to glomus tumour, but is not related to haemangiopericytoma.

Malignant glomus tumor in the branchial muscle of a 16-year-old girl

Malignant glomus tumor is an extremely rare neoplasm and its histological features are not well characterized. We report a 16-year-old female patient with a malignant glomus tumor. The patient was admitted to our hospital presenting with a mass in the right upper arm that she had noticed for the previous 6 months. Computed tomography and magnetic resonance imaging revealed an expanded mass involving the surrounding tissues. At surgery, an ill-defined and expanded mass was found, 5 x 4 x 3 cm in size, in the right branchial muscle. The tumor was extirpated, along with neighboring muscle tissues. Histologically, tumor cells were round to short-spindle shaped, forming solid sheets admixed with vessels of varying size. Their nuclei were uniformly oval to round, and their cytoplasms were slightly eosinophilic. The growth pattern of the tumor cells resembled that of glomus tumor, but mitotic figures were frequent (as high as 10 per 10 high-power fields). Immunohistochemically, the tumor cells were positive for vimentin and muscle actin, but negative for desmin. There were no areas typical of benign glomus tumor or sarcomatous change. These findings led us to a diagnosis of primary malignant glomus tumor arising de novo. There has been no recurrence or metastasis for 21 months after wide excision.

Malignant glomus tumor: a case report and review of the literature

Glomangiosarcoma, or malignant glomus tumor, is a very rare neoplasm that when seen typically arises from a benign glomus tumor. Despite having histologic features of malignancy, these tumors usually do not metastasize. However, when metastasis occurs this disease is often fatal. We report a case of a malignant glomus tumor arising de novo on the nose of an 89-year-old white woman, and we review the literature concerning glomangiosarcomas.

Atypical and malignant glomus tumors: analysis of 52 cases, with a proposal for the reclassification of glomus tumors

Occasional glomus tumors display unusual features, such as large size, deep location, infiltrative growth, mitotic activity, nuclear pleomorphism, and necrosis. Although a small number of purportedly malignant glomus tumors have been described, histologic criteria for malignancy in glomus tumors have never been elaborated. The authors studied 52 unusual glomus tumors (retrieved from their consultation files) previously diagnosed as "atypical" or "malignant" by virtue of nuclear atypia, infiltrative growth, or mitotic activity. They evaluated size, depth, growth pattern, cellularity, nuclear grade, number of mitotic figures per 50 high-power fields (HPF), atypical mitotic figures, vascular space involvement, and necrosis to define criteria for malignancy in glomus tumors. Estimated relative risk was calculated and the Fisher exact test was used for statistical analysis. The 27 female patients and the 25 male patients ranged in age from 8 to 83 years (median age, 43 years). The tumors measured from 0.2 to 12 cm (median size, 2 cm) and occurred predominantly in the extremities, in both the superficial (n = 35) and deep (n = 17) soft tissues. Atypical features were usually observed centrally with a rim of benign-appearing glomus tumor. Follow-up information (n = 35; range, 5 months-23 years; mean 5.5 years) showed seven recurrences, eight metastases, and seven deaths from disease. Five-year cumulative metastatic risk increased significantly for tumors with a deep location (p = 0.005), with a size of more than 2 cm (p = 0.004), and with atypical mitotic figures (p = 0.004). Mitotic activity of more than 5 mitoses/50 HPF, high cellularity, the presence of necrosis, and moderate to high nuclear grade approached but did not reach significance. High nuclear grade alone, infiltrative growth, and vascular space involvement were not associated with metastasis. The authors propose the following classification scheme and criteria. Malignant glomus tumor: Tumors with a deep location and a size of more than 2 cm, or atypical mitotic figures, or moderate to high nuclear grade and > or =5 mitotic figures/50 HPF. Symplastic glomus tumor: Tumors with high nuclear grade in the absence of any other malignant feature. Glomus tumor of uncertain malignant potential: Tumors that lack criteria for malignant glomus tumor or symplastic glomus tumor but have high mitotic activity and superficial location only, or large size only, or deep location only. Glomangiomatosis: Tumors with histologic features of diffuse angiomatosis and excess glomus cells. Using this classification scheme, metastasis was observed in 38% of tumors fulfilling the criteria for malignancy. In contrast, metastatic disease was not seen in any specimen classified as symplastic glomus tumor, glomus tumor of uncertain malignant potential, or glomangiomatosis.

Electron microscopy in tumor diagnosis: indications for its use in the immunohistochemical era

The electron microscope reveals much more information on tumor cell structure than can be obtained with the light microscope, and some of the data are useful in diagnostic studies. In this review, major contributions of electron microscopy in the main tumor categories are discussed. To select between immunocytochemistry and electron microscopy, the probable contributions of each in the context of the particular case must be assessed. Usually, electron microscopy will only be requested after a battery of immunostaining procedures has been performed and found to be insufficient, but there are occasions when ulstrastructural study is logically the first choice after routine light microscopy. It is worth taking tissue for possible electron microscopy from any tumor that is known or anticipated to be a diagnostic problem.

Glomangiosarcoma of the hip: report of a highly aggressive tumour with widespread distant metastases

Malignant glomus tumour is an extremely rare neoplasm, and only a few cases with local invasive or aggressive features have been described to date. We present a distinctive case of a malignant glomus tumor arising on the skin of the left hip of a 47-year-old woman. The primary tumour was small, with a maximum diameter of 1 cm, but 2 years after the tumour was excised, multiple lung and skin metastases appeared. Post-mortem examination also revealed widespread metastases in almost all of the visceral organs. Histological examination showed that the primary tumour was composed of a sheet-like proliferation of epithelioid round or short spindle cells surrounding small venules. In addition, there was a proliferation of long spindle cells with eosinophilic fibrillary cytoplasm, which mimicked a leiomyosarcoma. The tumour cells were intensely immunopositive for actin and vimentin but were negative for desmin. This is an exceptional case of malignant glomangiomyoma with widespread metastases, which represents a distinct variant of de novo glomangiosarcoma.

Histochemical investigation into the molecular mechanisms of malignant transformation in a benign glomus tumour

A glomangiosarcoma arose in a benign glomus tumour. The histological and immunohistochemical characteristics of the tumour were investigated. Apoptotic cells were identified by terminal deoxynucleotidyl transferase (TdT) mediated dUTP-biotin nick end labelling (TUNEL). The proportion of apoptotic cells was found to be low and TUNEL positive nuclei were present in the benign part of the tumour. Bcl-2 protein, an inhibitor of apoptosis, was strongly expressed in the glomangiosarcoma with only weak staining in the benign area. The proliferation index of the glomangiosarcoma was almost 10-fold higher than that of the benign glomus tumour. Numerous nuclei in the glomangiosarcoma were intensely stained for the tumour suppressor protein p53. The results of the this study may contribute to an understanding of the molecular basis of malignant transformation in benign glomus tumours.

Cutaneous vascular proliferations. Part III. Malignant neoplasms, other cutaneous neoplasms with significant vascular component, and disorders erroneously considered as vascular neoplasms

In this third and last part of our review of cutaneous vascular proliferations we include malignant vascular neoplasms and a group of heterogeneous cutaneous neoplasms characterized by a significant vascular component. We also review some disorders that, in our opinion, have been erroneously considered as vascular neoplasms. We review the epidemiologic, histogenetic, clinical, and histopathologic aspects of Kaposi's sarcoma in its four distinctive variants (classic, African-endemic, immunosuppressive drug-associated, and AIDS-associated Kaposi's sarcoma). There is still controversy about whether Kaposi's sarcoma represents a reactive vascular proliferation or a true neoplastic proliferation. In any event, most authors believe that Kaposi's sarcoma does not produce metastatic disease, but rather develops in multifocal fashion. However, Kaposi's sarcoma may cause death, especially in immunosuppressed patients. Epithelioid hemangioendothelioma, Dabska's tumor, and retiform hemangioendothelioma are examples of low-grade angiosarcoma. In contrast, cutaneous angiosarcomas, including the clinical variants of angiosarcoma of face and scalp in elderly patients, angiosarcoma associated with lymphedema, and radiation-induced angiosarcoma are highly aggressive neoplasms with poor prognosis and most patients die within a short period after presentation. A group of benign and relatively frequent cutaneous neoplasms, including multinucleate cell angiohistiocytoma, angiofibroma, angioleiomyoma, angiolipoma, cutaneous angiolipoleiomyoma, and cutaneous angiomyxoma are here covered because of their significant vascular component. Finally, we review briefly a series of cutaneous disorders that have been erroneously considered as vascular neoplasms. Kimura's disease is an inflammatory reactive condition of unknown origin, "benign" angioendotheliomatosis is a reactive intravascular proliferation of endothelial cells that occurs in the skin as a response to a variety of stimuli, "malignant" angioendotheliomatosis is an intravascular lymphoma, and acral pseudolymphomatous angiokeratoma of children (APACHE) is better interpreted as a pseudolymphoma.

Hereditary multiple glomangiomas

Hereditary multiple glomangiomas are an interesting rare problem which can either present as multiple painful cutaneous lesions or, rarely, a cosmetic challenge due to site, size or number of lesions. It may also pose a diagnostic dilemma, which can only be settled by biopsy. Malignant change in glomangioma is extremely rare and only a few cases are well documented in literature. A case report of this condition, along with extensive review of the literature, is presented. The prognosis of various forms of glomangiomas and efficacy of diagnostic and therapeutic tools is discussed.

Malignant glomus tumor of the thumb: a case report

Glomangiosarcoma is a rare malignant variant of the glomus tumor (GT). It has been reported in different anatomical locations, with only 1 report of its localization to the hand, despite the fact that its benign counterpart is most frequently found there. There is only 1 report of glomangiosarcoma that has metastasized. Special attention should be paid to GTs that are not well circumscribed, since the possibility of persistence and malignant transformation is increased in these lesions. The treatment of choice for glomangiosarcomas is wide local excision.

Glomangiosarcoma of the lower limb: a case report with a literature review

Glomangiosarcoma (GS) is a very unusual but morphologically distinctive tumor of soft tissue. We report a case of GS which occurred in the subcutaneous tissue of a 56-year-old man. Microscopically, a typical glomus tumor surrounded a central area of sarcoma. Immunohistochemical stains were performed, and there was a strong positive reaction for vimentin, muscle-specific actin and smooth muscle actin. We also review the clinicopathologic findings of the 9 GS that have previously been reported.

Malignant glomus tumor: a case report and review of the literature

This report concerns a malignant glomus tumor, a rare soft tissue tumor that was examined immunohistochemically and ultrastructurally. It occurred in a 44-year-old male patient who had suffered from dull pain and stiffness in the right thigh for 10 months. Radiographic examination revealed a well-defined osteolytic lesion in the diaphysis of the right femur. Hypervascularity of the tumor was observed angiographically. Computed tomographic and magnetic resonance examinations showed an intramuscular mass invading the marrow space of the femur. Wide resection was performed after open biopsy. Histologically, round to polygonal tumor cells revealed a uniform appearance of round to ovoid nuclei with single large nucleoli and slightly eosinophilic cytoplasm, forming solid sheets of cells interrupted by vessels of varying size. A few mitotic figures and vascular invasion were observed. Immunohistochemically, vimentin and alpha-smooth muscle actin were stained intensely, and muscle actin was positive for tumor cells of the perivascular area. Tumor cells were negative for desmin, factor VIII-related antigen, S-100 protein, neurofilament, cytokeratin, and epithelial membrane antigen. Ultrastructurally, tumor cells were characterized by many cytoplasmic processes, pinocytotic vesicles, plasmalemmal dense plaques, and scattered microfilaments in the cytoplasm. Few cell junctions and focal basement membrane-like structures were observed. No recurrence or metastasis was noted 57 months after operation. This case was considered to be a malignant glomus tumor, that is, a glomangiosarcoma arising de novo.

Atypical glomus tumor in the mediastinum: a case report with immunohistochemical and ultrastructural studies

A case is reported of atypical glomus tumor occurring in the posterior inferior mediastinum of a 26-year-old woman complaining of severe back pain. The tumor was composed of atypical small, round tumor cells with scattered mitotic figures. In addition to sheet-like, diffuse proliferation of the tumor cells, some areas of the tumor contained small "glomoid" cells arranged in organoid and hemangiopericytomalike patterns. Immunohistochemically, many tumor cells were positive for muscle-type actins and a few cells were focally positive for desmin. Ultrastructural studies revealed smooth muscle features of tumor cells, that is, pinocytotic vesicles, external laminas, dense plaques, and occasional thin filaments with dense bodies. The patient remained well for 5 years and 4 months after the operation without additional radiation and chemotherapy. The tumor was diagnosed as an atypical, or low-grade malignant, glomus tumor morphologically. It seems important to recognize the presence of this type of tumor in sites other than extremities and to differentiate it from other malignant small, round cell tumors.

Malignant glomus tumor. A case report of widespread metastases in a patient with multiple glomus body hamartomas

Glomus tumors are characteristically benign solitary tumors. A few cases of malignant glomus tumors have been reported; however, they are usually only locally invasive, and metastases are exceedingly rare. We report a case of widespread metastases of a malignant glomus tumor involving the skin, lungs, jejunum, liver, spleen, and lymph nodes in a 63-year-old man with end-stage chronic renal failure. At autopsy, multiple glomus body hamartomas were also noted throughout the dermis proximal to the skin tumors. Histologically, the tumor was composed of monotonous round cells in solid sheets and investing numerous capillary-sized vessels. Approximately four to six mitoses were present per high-power field. The tumor cells were strongly immunoreactive for actin and vimentin, and ultrastructurally there were whorls of microfilaments with focal condensations. This case is exceptional because of its aggressive course.

Glomus tumor. A histological, histochemical and immunohistochemical study of the various types

Glomus tumors are benign lesions composed of vessels and glomocytes in varying proportions. The histological appearance of the tumors depend upon the ratio of the vascular to the glomus cells and their differentiation as well as upon the amount and composition of the stroma. The aim of the present study was the establishment of criteria for the distinction of glomus tumor-like malformations from neoplasms with glomus cell differentiation. Using a panel of monoclonal and polyclonal antibodies (vimentin, a-smooth muscle actin, desmin, pan-keratin, low molecular weight cytokeratin, EMA, NSE, S-100 protein, Factor VIII, a1-ACT) glomus tumors could be separated into three types: vascular, cellular with myxoid stroma and cellular, solid type. In the first two types the tumor growth is composed of all three components found in normal glomus body, but in a haphazard fashion and thus might be considered as tumor-like malformations. The third type is composed of perivascular arranged cells most of which acquire the phenotypical characteristics of glomocytes. This last tumor probably represent the neoplastic variant of the group of lesions designated by the term glomus tumor.

Intravascular glomus tumour: a previously undescribed phenomenon

We report the first case of an intravascular glomus tumour, which was located in the right forearm of a 40-year-old male. Microscopically the lesion originated from the wall of a vein and protruded into the lumen of the affected blood vessel. The tumour cells were characterized immunohistochemically by the presence of vimentin, actin and myosin. Within the tumour, small nerves, immunopositive for S-100 protein and neurofilaments, could be identified. Histogenetically, the tumour is thought to derive from intramural epithelioid cells of the venous part of an arteriovenous anastomosis.

Localized form of multiple glomus tumors: report of the first case showing partial involution

We recently examined a boy with relatively large multiple glomus tumors on the left scapular region. Histologic examination revealed a typical non-capsulated glomangioma in the middle and deep dermis; by electron microscopic examination, the tumor cells were seen to exhibit a characteristic smooth muscle cell structure. Thermographic examination revealed the higher temperature of the tumor. Within a year, the tumor showed a partial involution. We think this is the first report of multiple glomus tumor showing a partial involution.

Locally infiltrative glomus tumors and glomangiosarcomas. A clinical, ultrastructural, and immunohistochemical study

Six cases of locally aggressive and/or potentially malignant glomus tumors are described. On the basis of clinical and pathologic criteria, the following classification is proposed. The first category is a locally infiltrative glomus tumor (LIGT) which has the usual glomus histologic features. The second group is a cytologically malignant tumor arising and merging with a typical glomus tumor, designated glomangiosarcoma arising in a benign glomus (GABG). The third category and the most difficult to recognize is the de novo glomangiosarcoma (GADN), which must be distinguished from other round cell sarcomas. Most of these locally aggressive glomus tumors are vimentin positive and are immunoreactive for muscle-specific actin. Electron microscopic examination in one GABG case showed cells with numerous microfilaments and pinocytotic vesicles; a second GADN case contained cells with microfilaments and an incomplete basal lamina. As a group these locally aggressive or potentially malignant glomus tumors are larger and more deeply located than the conventional glomus tumor. Although 50% of these tumors recurred locally, none have metastasized.

Glomus tumours: an immunohistochemical profile of 11 cases

We studied 11 glomus tumours immunohistochemically, with a panel of connective tissue and epithelial markers. Most tumours contained small nerve fibres located in connective tissue septae between groups of glomus cells, thus accounting for the frequent occurrence of pain associated with glomus tumours. All tumours stained positively for muscle-specific actin and vimentin. Immunostaining for high and low molecular weight cytokeratins, desmin, myoglobin, S-100 protein, neurofilaments and Factor VIII related antigen was negative. Our findings confirm and amplify the proposed smooth muscle histogenesis of glomus tumours. This immunohistochemical profile may be of diagnostic value in the differential diagnosis of atypical glomus tumours.