Histogenesis of alveolar soft part sarcoma. An immunohistochemical and biochemical study

Alveolar Soft Part Sarcoma of the Vagina

We describe a case of primary alveolar soft part sarcoma presenting as a vaginal mass in a 27 year old woman and also review the literature on this type of tumor arising in the lower female genital tract. Histologically, most of the tumor exhibited poorly developed alveolar architecture, but anaplasia was absent. Although the mass was well circumscribed, a few tumor cells were seen focally within the peritumoral tissue. Treatment consisted of wide local excision followed by external radiation therapy. The patient is alive without evidence of disease 17 years after operation.

Different desmin peptides are distinctly deposited in cytoplasmic aggregations and cytoplasm of desmin-related cardiomyopathy patients

Desmin-related cardiomyopathy is a heterogeneous group of myofibrillar myopathies characterized by aggregates of desmin and related proteins in myocytes. It has been debated how the expression and protein structure are altered in the aggregates and other parts of myocytes in patients. To address this question, we investigated the proteome quantification as well as localization in formalin-fixed and paraffin-embedded specimens of the heart of patients by imaging mass spectrometry and liquid chromatography-mass spectrometry analyses. Fifteen tryptic peptide signals were enriched in the desmin-related cardiomyopathy myocardium, twelve of which were identified as desmin peptides with 14.3- to 27.3-fold increase compared to normal hearts. High-intensity signals at m/z 1032.5 and 1002.5, which were desmin peptides 59-70 at the head portion and 213-222 at the 1B domain, were with infrequent colocalization distributed not only in desmin-positive intracytoplasmic aggregates but also in histologically normal cytoplasm, indicating that desmin protein is fragmented and different types of naturally-occurring truncated proteins ectopically assemble throughout the heart of patients. Thus, in addition to conventional histological identification of protein aggregates, specific desmin peptides show a marked difference in quantity and localization in a tissue section of desmin-related cardiomyopathy and differentiate from other cardiomyopathies. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.

Primary Pulmonary Alveolar Soft-part Sarcoma

Alveolar soft-part sarcoma rarely arises in the lung. Only two patients with tumors that were apparently primary in the lung have been documented in the literature. We report an additional case in a 25-year-old woman. The tumor formed a solitary 5 cm, solid mass in the left perihilar region. Clinical examination, radiologic studies, and follow-up examination of more than 1 year have failed to reveal tumor in an extrapul monary location. The light microscopic appearance was typical for alveolar soft-part sarcoma, and crystalloids were identified in the tumor cells by the periodic acid-Schiff stain and by electron microscopy, confirming the diagnosis. Immunocytochemical studies did not show evidence of myogenic, epithelial, or neuroendocrine differentia tion. Int J Surg Pathol 2(1):57-62, 1994

Alveolar Soft Part Sarcoma of the Extremity: Case Report and Literature Review

Alveolar soft part sarcoma (ASPS), a rare soft tissue sarcoma in children and adolescents, carries a poor prognosis. ASPS is an aggressive tumor of controversial histogenesis that, unlike other soft tissue sarcomas, tends to metastasize to the brain. A 9-year-old boy presented to our outpatient clinic in April 2009 with a chief complaint of a large painless mass in the left thigh whose size had increased significantly over the past 10 months. After staging the tumor, we performed open biopsy; the diagnosis was ASPS and he underwent wide local excision. In the course of 4-year follow-up by clinical and imaging studies, there was no evidence of early tumor recurrence or metastasis. Complete surgical resection is the treatment of choice in patients with ASPS.

Alveolar soft part sarcoma of the frontal calvarium and adjacent frontal lobe

Alveolar soft part sarcoma is a rare tumor affecting mainly adolescent and young children. It presents as a slowly growing tumor and is usually overlooked due to lack of symptoms. Early metastasis is a characteristic feature of this tumor and, in a good number of cases, metastasis to the lung or brain is the first manifestation of the disease. In this report, we present a case of alveolar soft part sarcoma predominantly located in the right frontal bone with dural breach and contiguous right frontal lobe involvement in a 17-year-old girl without any evident primary or other secondaries. A brief review of literature is also presented.

Alveolar soft part sarcoma metastasized to both the skull and the brain

Alveolar soft part sarcoma (ASPS) with skull and brain metastases is extremely rare. A 53-year-old patient diagnosed as skull metastasis of ASPS visited our clinic complaining of an outgrowing scalp mass in spite of radiation therapy. Past medical history revealed that the patient had been diagnosed and treated for ASPS of the thigh 4 years ago. Magnetic resonance imaging revealed a hyperintense ovoid mass on the T2-weighted image, an isointense on the T1-weighted image, and a homogeneous enhanced mass with gadolinium. Another small-sized enhanced mass with mild peritumoral swelling was found at the deep white matter of the left frontal lobe. A gross total resection of the skull lesion with cranioplasty was performed for the surgical defect. A histologic examination of the specimens revealed metastatic ASPS involving the skull. Surgery with a total removal of the lesions may be effective for improving a patient's symptoms especially from neurological dysfunction.

Alveolar soft part sarcoma of the tongue in a 3-year-old boy: a case report

Introduction

Alveolar soft tissue sarcoma of the tongue is a very rare and aggressive tumor which occurs in infancy with a relatively controversial histogenesis. It may mimic benign vascular neoplasms and may metastasize to the lungs, brain or bones.

Case presentation

We present the case of a three-year-old Caucasian boy who was admitted to our department with a history of dysphagia and two episodes of oral bleeding which had lasted for a period of six months. A thorough histological examination together with imaging techniques form the basis of a reliable diagnosis.

Conclusion

Alveolar soft tissue sarcoma of the tongue is a rare tumor which occurs in infancy and which is often misdiagnosed pre-operatively. It should therefore be included in the differential diagnosis of oral pediatric lesions.

Molecular analyses of cell origin and detection of circulating tumor cells in the peripheral blood in alveolar soft part sarcoma

Alveolar soft part sarcoma (ASPS) is a distinct, rare soft tissue tumor with an unknown histogenesis and a tendency for late widespread metastases to lung, bone, and brain. It is now clear that they are caused by a specific unbalanced translocation, der(17)t(X;17)(p11;q25), which results in the formation of an ASPSCR1-TFE3 (alias ASPL-TFE3) fusion gene. The rearrangement results in the expression of chimeric transcripts, which can be identified by means of reverse transcriptase-polymerase chain reaction (RT-PCR). We investigated the histogenesis of ASPS and attempted to detect circulating ASPS tumor cells in peripheral blood. The immunohistochemical and genetic details of four cases and one cell line of ASPS were examined. An immunohistochemical analysis and RT-PCR did not detect myogenic differentiation gene MYOD1. The sensitivity of nested RT-PCR for detection of circulating ASPS cells was assessed by demonstrating that the tumor cell-associated gene translocation could be detected in 50 tumor cells/2 mL of blood. Clinically, it was detectable in a peripheral blood sample (2 mL) of ASPS patient with distant metastases. The findings suggest that ASPS is not of skeletal muscle origin. ASPS tumor cells in the peripheral blood could be monitored by RT-PCR.

Gene expression profiling of alveolar soft-part sarcoma (ASPS)

Background

Alveolar soft-part sarcoma (ASPS) is an extremely rare, highly vascular soft tissue sarcoma affecting predominantly adolescents and young adults. In an attempt to gain insight into the pathobiology of this enigmatic tumor, we performed the first genome-wide gene expression profiling study.

Methods

For seven patients with confirmed primary or metastatic ASPS, RNA samples were isolated immediately following surgery, reverse transcribed to cDNA and each sample hybridized to duplicate high-density human U133 plus 2.0 microarrays. Array data was then analyzed relative to arrays hybridized to universal RNA to generate an unbiased transcriptome. Subsequent gene ontology analysis was used to identify transcripts with therapeutic or diagnostic potential. A subset of the most interesting genes was then validated using quantitative RT-PCR and immunohistochemistry.

Results

Analysis of patient array data versus universal RNA identified elevated expression of transcripts related to angiogenesis (ANGPTL2, HIF-1 alpha, MDK, c-MET, VEGF, TIMP-2), cell proliferation (PRL, IGFBP1, NTSR2, PCSK1), metastasis (ADAM9, ECM1, POSTN) and steroid biosynthesis (CYP17A1 and STS). A number of muscle-restricted transcripts (ITGB1BP3/MIBP, MYF5, MYF6 and TRIM63) were also identified, strengthening the case for a muscle cell progenitor as the origin of disease. Transcript differentials were validated using real-time PCR and subsequent immunohistochemical analysis confirmed protein expression for several of the most interesting changes (MDK, c-MET, VEGF, POSTN, CYP17A1, ITGB1BP3/MIBP and TRIM63).

Conclusion

Results from this first comprehensive study of ASPS gene expression identifies several targets involved in angiogenesis, metastasis and myogenic differentiation. These efforts represent the first step towards defining the cellular origin, pathogenesis and effective treatment strategies for this atypical malignancy.

Alveolar soft part sarcoma: clinicopathological findings in a series of 11 cases

Background

Alveolar sarcoma of the soft parts (ASPS) represents a very rare entity of soft tissue sarcoma with special features such as young peak age incidence and frequent metastasis to the brain. The aim of this study was a clinicopathological analysis with special reference to treatment and outcome.

Methods

From the database of the BG-University Hospital Bergmannsheil, 1597 soft tissue sarcoma (STS) cases were reviewed and 11 consecutive patients with ASPS were isolated. Data was acquired from patients' charts and contact to patients, their relatives or general practitioners, with special reference to treatment and clinical course. The average follow up time from the time of the definite operation for the primary tumor was 6.5 years. Kaplan-Meier method was used to calculate survival.

Results

Patients with localized disease who received complete resection and adjuvant radiation and who did not develop recurrence or metastatic disease within 2 years after surgery had a positive outcome. The size of the tumor, its localization, and the time of untreated growth before treatment did not influence the long-term results. All patients who developed recurrent disease also suffered from distant metastasis, reflecting the aggressive biology of the tumor. All patients with distant metastasis had the lungs and the brain affected.

Conclusion

Due to the limited number of patients with ASPS, prospective studies would have to span decades to gather a significant collective of patients; therefore, it is not possible to comment meaningfully on a possible benefit of neoadjuvant or adjuvant therapy.

We recommend wide surgical excision and, in the absence of data telling otherwise, adjuvant radiation. In cases with recurrent disease or metastasis, the prognosis is bad and further treatment will be restricted to palliation in most cases.

Alveolar soft part sarcoma: report of a case occurring in the sinonasal region

A primary alveolar soft part sarcoma arising in the nasal-paranasal sinuses region is quite rare. In this report, a 14-year-old boy with typical features of alveolar soft part sarcoma of the nasal and paranasal sinuses is presented. Treatment was surgical excision of the mass combined with radiotherapy. There has been no recurrence or metastasis as of 2 years after treatment.

Pathologic and molecular aspects of soft tissue sarcomas

This article retains the conventional approach to the classification of soft tissue sarcomas, dividing them into several major histogenetic categories based on their overall microscopic appearance, tissue differentiation pattern, and biologic potential. The author advocates a multimodal approach, in which four distinctive data sets--clinical, radiographic, microscopic, and, in some cases, molecular--are considered to establish the diagnosis and treatment plan. Such step-wise analysis is more likely to lead to consistency and accuracy as compared with an intuitive approach based on fragmentary data. The author describes individual lesions of soft tissue as clinicopathologic entities and believes that they can be more accurately diagnosed and appropriately treated with the help of data generated by a multidisciplinary team. In addition, this article emphasizes the need to use emerging molecular techniques that can provide important clues for both diagnosis and prognosis.

Alveolar soft part sarcoma. a report of 15 cases

The aim of this study was to evaluate the presentation, course and treatment outcome of 15 patients with this rare type of sarcoma. The files of the patients were retrospectively analysed. Overall survival was calculated according to the Kaplan-Meier method. There were 15 patients, 8 male and 7 female. The mean age at diagnosis was 29 years for men and 24 years for women. The median survival was 48 months with an overall 5-year survival of 38%. 5 patients had haematogenic metastases at the time of diagnosis. For the remaining 10 patients with localised disease, the median survival was 48 months and the 5-year survival 48%. The median disease-free survival for these patients was 12 months with a 5-year disease free survival of 40%. After the occurrence of haematogenic metastases, patients survived a median period of 8 months (range 0-45 months). 5 patients are still free of disease after a median period of 234 months (12-295 months). Alveolar soft part sarcoma is found especially in young adults. When diagnosed, it is often metastasised with a poor prognosis. However, when radically resected, long-term survival is possible.

Primary alveolar soft part sarcoma of the stomach: a case report and review

Alveolar soft part sarcoma (ASPS) is a rare tumor typically located in skeletal muscles and muscolofascial planes. Isolated cases of ASPS have been described as arising in the viscera. We report a mesenchymal tumor of the stomach in a 54-year-old Italian woman without evidence of primary neoplasm elsewhere ten years following the initial diagnosis. The histologic, histochemical, immunohistochemical, and electron microscopic findings were all consistent with the diagnosis of ASPS and allowed differentiating it from morphologically similar and more common tumors, such as metastatic renal cell carcinoma and paraganglioma. The patient is alive and well ten years following the initial presentation.

Alveolar soft part sarcoma of the tongue: report of an unusual pattern in a child

A case of an unusual, primary alveolar soft part sarcoma of the tongue in a 3-year-old boy is presented. Alveolar soft part sarcoma is a rare malignant tumor that presents more frequently in the head and neck region of infants and children. To date, only six cases of lingual alveolar soft part sarcoma presenting in the first decade of life have been reported in the English literature. The patient has undergone surgical resection without adjuvant chemotherapy or radiation. Thus far, the patient does not manifest persistent or recurrent disease.

Immunohistochemical profile of myogenin and MyoD1 does not support skeletal muscle lineage in alveolar soft part sarcoma

BACKGROUND

The histogenesis of alveolar soft part sarcoma remains elusive. Myogenic origin is favored, although conflicting data on immunohistochemical demonstration of muscle-associated markers exist. Myogenin and MyoD1, transcription factors of the myogenic determination family, have crucial roles in commitment and differentiation of mesenchymal progenitor cells to myogenic lineage and in maintenance of skeletal muscle phenotype. Their immunohistochemical detection is specific in characterization of rhabdomyosarcoma.

METHODS

Antibodies for myogenin, MyoD1, desmin, and muscle-specific actin were employed on a large series of cases (n = 19) of formalin-fixed, paraffin-embedded alveolar soft part sarcoma.

RESULTS

Minimal scattered nuclear staining was seen with myogenin. All cases had pronounced, nonspecific granular cytoplasmic immunostaining with MyoD1; nuclei were negative. All tumors were negative for desmin and muscle-specific actin. Ultrastructural study in 10 cases failed to reveal features of skeletal muscle differentiation.

CONCLUSIONS

Cytoplasmic staining with MyoD1 in alveolar soft part sarcoma may correspond to cross-reactivity with an undetermined cytoplasmic antigen. The lack of immunostaining with myogenin, MyoD1, desmin, and muscle-specific actin provides evidence against a myogenic origin for alveolar soft part sarcoma.

Alveolar soft part sarcoma of the head and neck region

Alveolar soft part sarcoma is a soft tissue malignancy most often found in the extremities of young adults; when these tumors arise in the head and neck area, they usually appear in the orbit or the tongue. Their initial behavior is relatively indolent, but over time a sizable number of these tumors recur locally and metastasize; as such, they are best regarded as fully malignant neoplasms. The derivation of these tumors remains uncertain: while some have suggested that these are tumors of muscle origin and others have postulated a neuroendocrine origin, the evidence accumulated to date is conflicting, and so these neoplasms continue to be regarded as tumors of uncertain origin. Surgical excision is the mainstay of therapy.

Ultrastructural studies of tubules, analogous to skeletal cell T-tubules, in alveolar soft part sarcoma

Tumor tissues from six patients with alveolar soft part sarcoma (ASPS) were investigated ultrastructurally to determine the presence of smooth tubules associated with plasmalemmal invaginations. Two different types of smooth tubular structures were identified: an aggregated and a dispersed type. The aggregated type (found in one of the six ASPSs) showed marked aggregation of many elongated smooth tubules without ribosomes associated with the plasmalemma. In the dispersed type (observed in the remaining five ASPSs), there was a conspicious appearance of a few smooth tubules scattered throughout the cytoplasm. Smooth tubules were the main component in both types, suggesting that both types appeared to have the same origin, although there were some differences in number, appearance, and distribution of the tubules between the two types. The smooth tubules in both types were classified into three different subtypes on the basis of materials in the tubular lumen. Ultrastructual observation and a plasmalemmal tracer-method, showed smooth tubules in continuity with the plasmalemma in three of the six cases, indicating that the tubules originated from the plasmalemma. Since the tubular structures were found in the tumor tissues of all six patients, they are probably one of the characteristic features of ASPS.

Alveolar soft-part sarcoma: a review of the pathology and histogenesis

The descriptive designation, alveolar soft-part sarcoma, continues to be used for this uncommon soft-tissue malignancy because an acceptable hypothesis for its histogenesis has not been advanced, despite studies with electron microscopy and immunohistochemistry. These techniques have, nevertheless, provided significant information that is useful in the differential diagnosis of the tumor and pertinent in speculation concerning its nature. The most intriguing ultrastructural feature is the secretory process that culminates in the formation of the distinctive cytoplasmic crystals. Myogenic differentiation has been favored in a number of recent reports on the basis of immunohistochemical findings and the presence of the crystals does not rule out the possibility, but accounts of immunoreactivity for the myogenic regulatory protein MyoD1 have not been confirmed in subsequent studies or in the authors' own staining of six cases.

Alveolar soft part sarcoma: review of nine cases including two cases with unusual histology

AIM

Alveolar soft part sarcoma is a very rare tumour. Nine cases are reviewed in order to identify new aspects of this tumour.

METHODS AND RESULTS

The clinical course, histological, immunohistochemical and ultrastructural features of nine cases of alveolar soft part sarcoma were reviewed. Proliferative activity and p53 protein accumulation were assessed immunohistochemically. The patients were aged between 18 and 70 years. In the cases with sufficient follow-up, survival was variable with two patients dying within 5 months and four alive at 4 years. Histologically all tumours had an alveolar component but one case also had a spindle component and another case had a pseudoglandular pattern. Six cases showed desmin immunoreactivity, one was muscle-specific actin positive, two were positive for S100 protein and three were positive for vimentin. MIB-1 immunostaining was seen in up to 35% of cells. Two cases showed p53 protein accumulation.

CONCLUSIONS

There appeared to be no correlation between short term survival (4 years or less) and clinical presentation, adjuvant treatment, tumour size, histological grade, vascular invasion by tumour, proliferative index, or p53 protein accumulation. Although unusual, spindle cell or pseudoglandular components can be seen in alveolar soft part sarcoma.

Successful treatment for solitary brain metastasis from alveolar soft part sarcoma

Following pulmonary metastases, alveolar soft part sarcoma has an unexplained predisposition to metastasize to the brain. Herein, a case of alveolar soft part sarcoma solitarily metastatic to the brain is described. A 23-year old female underwent the resection of alveolar soft part sarcoma from the right thigh. Three years after the surgery, a brain tumor was resected and pathology proved it was a metastatic alveolar soft part sarcoma. She is currently alive and well 6 years after brain surgery. Our report suggests that surgical resection for solitary brain metastasis from alveolar soft part sarcoma is an effective treatment modality.

Smooth tubular aggregates associated with plasmalemmal invagination in alveolar soft part sarcoma

The ultrastructure of four alveolar soft part sarcomas was examined to search for ultrastructural signs of myogenic or neural origin. A new ultrastructural structure, an unusual tubular structure, was found in two of four cases. The structure appeared as a large, smooth, tubular aggregate in the cytoplasm of some tumor cells but did not show a honeycomb arrangement of tubules. The aggregate was composed of long, serpentine, branching, smooth, irregularly arranged tubules without ribosomes that ran in various directions. The aggregates intermingled with small amounts of cytoplasmic organelles. Because the aggregated tubules were at times continuous with cell membranes, it was shown that they were the complex extensions or invaginations of cell membranes. Neither myelin-axon complexes nor myofilaments, including Z band material, were seen in any case. There was a possibility that the smooth tubular aggregate was a T-tubule-like structure, suggesting that the tumors were derived from skeletal muscle cells.

Alveolar soft-part sarcoma: evidence for its myogenic origin and for the involvement of 17q25

A typical case of alveolar soft-part sarcoma was examined using ultrastructural, immunohistochemical and cytogenetic methods. Immunohistochemical stains were performed on frozen sections and showed strong desmin expression with the three anti-desmin antibodies used. In addition, the tumour cells were weakly positive for vimentin and myosin. Neural markers were negative. Chromosomal analysis showed consistent involvement of 17q25--an abnormality which has been reported in another alveolar soft-part sarcoma. The histogenesis of alveolar soft-part sarcoma is still debatable but our findings support a myogenic origin. The finding of an apparently identical chromosomal abnormality in two of three thus far examined cases of alveolar soft-part sarcoma is of interest and must await further confirmation, but it may result in the identification of a chromosomal marker for this enigmatic tumour and thus pave the way for further molecular elucidation.

Alveolar soft part sarcoma of the uterine cervix

A rare case of an alveolar soft part sarcoma of the uterine cervix in an 8 year old girl is presented. The patient was admitted because of genital bleeding lasting for 7 months. A polypoid tumor, 2 x 1.5 cm in diameter, was found in her external uterine os and was surgically resected. Microscopically, the tumor consisted of a uniform sheet of tumor cells in the cytoplasm which contained granules and which were stained with periodic acid-Schiff, both before and after the diastase digestion. Alveolar arrangement of the tumor cells was manifested with reticulin silver impregnation. Dense, membrane bound granules were evident at an ultrastructural level in the cytoplasm of the tumor cells. An immunohistochemical examination demonstrated a positive reaction for anti-desmin, anti-myoglobin, anti-HHF35 and anti-neuron specific enolase in the cytoplasm.

Alveolar soft part sarcoma of the pulmonary vein

Alveolar soft part sarcoma of the lung seen in a 42-year-old female is reported. In the partial pneumonectomy specimen, there was a 3 x 2.5 cm tumor arising from the pulmonary vein at the level of the right lung hilus, with tumor thrombus formation. The transition between the tumor and venous smooth muscle layer was microscopically confirmed. At autopsy, performed 18 months after surgery, metastases were noted in the left lung and brain. No primary focus was identified in the soft tissue. The alveolus-forming clear tumor cells contained diastase-resistant periodic acid-Schiff-reactive granules. Immunohistochemically, granular cytoplasmic reactivities with monoclonal antibodies against pan-actin and alpha-sarcomeric actin were demonstrated, whereas other muscle markers such as desmin, alpha-smooth muscle actin, myoglobin, fast skeletal myosin, and the mm-isozyme of creatine kinase were negative. Ultrastructurally, crystallized structures were occasionally identified in the membrane-bound, electron lucent granules, which often filled the tumor cell cytoplasm. The muscle cell nature of the neoplasm is discussed.

An unusual organoid tumor. Alveolar soft part sarcoma or paraganglioma?

The histogenesis of alveolar soft part sarcoma (ASPS) is a subject of continued debate. Although many recent reports suggest a muscle origin, others advocate a neuroendocrine derivation. A tumor in the chest wall of a 16-year-old woman was diagnosed and treated as ASPS. The light microscopic, electron microscopic, and immunohistochemical findings showed features of both ASPS and paraganglioma. In addition, this lesion was positive for antibody to glucagon, a characteristic of neither ASPS nor paraganglioma, although seen in a few gangliocytic paragangliomas. This case demonstrates the need for continued inquiry into the histogenesis of ASPS.

Membrane-bound cytoplasmic crystals, similar to those in alveolar soft part sarcoma, in a human muscle spindle

Membrane-bound cytoplasmic crystals were found in the intrafusal fibers of a muscle spindle from a patient with neurogenic atrophy. The crystals have a periodicity of 10 nm and an intersecting axis angle of approximately 80 degrees. This makes the crystals similar to those described in alveolar soft part sarcoma (ASPS). Because the crystals in ASPS may not be quite as specific as previously believed, and because similar crystals have been described in various other neoplasms, the present findings should not be taken as evidence for a muscle spindle derivation for ASPS.

Alveolar soft part sarcoma: a case report with immunohistochemical study

We report herein, a rare case of a 28 year old Japanese man with alveolar soft part sarcoma. The patient noticed a rapidly growing mass in the inner aspect of his left thigh and a smooth-surfaced, hard nodule revealing bruit on auscultation was found on physical examination. An angiogram showed dense neovascularity from the left profunda femoris artery. Histopathologically, the tumor was composed of nests of tumor cells with hyperchromatic nuclei and vesicular cytoplasm arranged in an alveolar fashion and a histopathologic diagnosis of alveolar soft part sarcoma was made. Immunohistochemically, the tumor cells had desmin and vimentin immunoreactants in the cytoplasm, suggesting muscle origin.

Alveolar soft part sarcoma. A clinicopathologic and immunohistochemical study of 12 cases

Twelve cases of alveolar soft part sarcoma (ASPS) were reviewed. Seven of them arose primarily in the lower extremities, three in the head and neck region, and two in other parts. ASPSs in the head and neck region occurred in children before 10 years of age, whereas ASPSs in the other regions occurred in rather older patients. Moreover, ASPSs of the head and neck were relatively small in size, and were diagnosed earlier than those in other regions. Histologically, six cases (including all the head and neck cases) contained considerable area of small and indistinct alveolar structures. Four cases showed remarkable cellular pleomorphism. Immunohistochemical demonstration of vimentin, desmin, the beta-subunit of enolase and the MM isozyme of creatine kinase, together with the absence of immunoreactive cytokeratin, supported the myogenic nature of this rare tumor. A small number of S-100 protein-positive tumor cells were also observed. Follow-up data for these cases disclosed that the tumors containing considerable area of small alveoli and uniform small tumor cells formed distant metastases at an early stage.

Cytoskeletal properties of alveolar soft part sarcoma

The immunohistochemical expression of cytoskeletal proteins in alveolar soft part sarcoma (ASPS) was studied by light and electron microscopy. Of the five cases examined by the avidinbiotin-peroxidase complex method, variable numbers of immunoreactive cells for desmin were found in three, for vimentin in two, for muscle-specific actins in three, and for alpha-smooth muscle actin in four. Immunoelectron microscopic study demonstrated that desmin and vimentin were localized on whorled bundles of intermediate filaments in the perinuclear cytoplasm. In addition, a few dispersed intermediate filaments became evident in specimens treated with saponin and fixed with tannic acid. These immunohistochemical results indicate that a few tumor cells of ASPS may express some properties of the cytoskeleton of smooth muscle cells in addition to those of skeletal muscle cells. Considering the discrepancies reported in the actin isoforms demonstrated in myogenic tumors, we conclude that ASPS is probably a peculiar, primitive myogenic tumor that does not show any distinctive features of rhabdomyogenic or leiomyogenic differentiation.

Alveolar soft part sarcoma: an electron microscopic study especially of uncrystallized granules using a tannic acid-containing fixative

Electron microscopic observation of alveolar soft part sarcoma reveals crystalline structure as well as granules that are only partially composed of crystalloids. The uncrystallized part has been observed only as a dense amorphous substance by the conventional fixation method with glutaraldehyde or osmium tetroxide (or both). Some investigators have explained the uncrystallized areas as artifacts due to the fixation method and as being essentially crystallized; other investigators consider the dense amorphous material the prodromal state of crystallization. In this study, however, which used the fixation method most appropriate for the intracytoplasmic filaments (fixation in tannic acid-containing glutaraldehyde and postfixation in osmium tetroxide) after increasing the permeability of the filaments to the fixative by pretreatment with a nonionic detergent (Triton X-100), the uncrystallized part was revealed to consist of an aggregation of many uncrystallized filaments with the same diameter (6 nm) as that of the crystallized filamentous structures. That is, the uncrystallized part was found to have been present as the prodromal state of crystallization and as filaments.

Alveolar soft part sarcoma of the head and neck. A disease of children and young adults

Alveolar soft part sarcoma (ASPS) is a rare malignancy of uncertain histologic origin that predominantly afflicts female children and young adults. Forty-three cases occurring in the head and neck have been identified, to which we add a case. The most frequent sites of occurrence in the head and neck are orbit and tongue. Treatment is universally surgical, with limited roles for adjuvant radiotherapy and chemotherapy. Representative populations of patients with orbital, non-orbital and extremity ASPS are compared statistically. Improved disease-free intervals in orbital ASPS vs non-orbital ASPS and head and neck ASPS vs extremity ASPS are documented. Debate exists regarding the histologic origin of ASPS. The additional case presented does not corroborate recent immunohistochemical studies suggesting myogenic origin. Nevertheless, the clinical pattern of disease offers additional support to the myogenic hypothesis of histologic origin.

Rhabdomyosarcoma in middle-aged and elderly individuals

In a review of a national series of malignant tumors in middle-aged and elderly individuals (over 40 years of age), in all 107 cases primarily diagnosed and reported to the Swedish Cancer Registry as rhabdomyosarcomas during the period 1972-1981, 4 cases were accepted as botryoid, embryonal or alveolar rhabdomyosarcoma, using light-microscopic criteria for the diagnosis. An electron-microscopic and immunohistochemical analysis was performed on the 4 cases along with 7 cases of botryoid, embryonal and alveolar rhabdomyosarcoma in patients of over 40 years of age obtained from our own files. Rhabdomyoblastic differentiation was established ultrastructurally by the presence of myofilaments and Z-like densities in 10 of these 11 cases. There were tumor cells in the formaldehyde-fixed, paraffin-embedded material which were positively stained for desmin in all cases, for myoglobin in 7/11 cases, for vimentin in 5/11 cases and for actin in all cases, using monoclonal antibodies. The demonstration of desmin by the monoclonal antibody which was used on the formaldehyde-fixed, paraffin-embedded material is of particular value in the diagnosis of rhabdomyosarcoma. Another tumor, located in the minor pelvis, lacked the light-microscopic features of botryoid, embryonal or alveolar rhabdomyosarcoma, but presented ultrastructural and immunohistochemical evidence of a rhabdomyoblastic differentiation. This tumor was epithelioid in appearance and shared features with alveolar soft part sarcoma. The label epithelioid rhabdomyosarcoma is proposed for this tumor. Nine pleomorphic sarcomas were selected from the national series as possible pleomorphic rhabdomyosarcomas because of the presence of ribbon-shaped tumor cells with an eosiniphilic cytoplasm. There was no electron-microscopic or immunohistochemical evidence of a myogenic differentiation in any of these 9 tumors. The present investigation indicates that a pleomorphic type of rhabdomyosarcoma, indistinguishable from embryonal, botryoid and alveolar rhabdomyosarcoma, is extremely rare or non-existent.

Alveolar soft part sarcoma of the cervix uteri. A case report

A case of alveolar soft part sarcoma (ASPS) of the cervix uteri of a 32-year old woman is described. Its differential diagnosis from histologically similar tumours is discussed. ASPS has been reported in the cervix uteri in one instance only in the literature. In spite of their unusual localization, these cases have to be recognized in order to avoid improper treatment.

Alveolar soft part sarcoma. Assessment of immunohistochemical demonstration of desmin using paraffin sections and frozen sections

The many different theories on the histogenesis of alveolar soft part sarcoma (ASPS) have caused great confusion. Owing to the recent rapid advance in immunohistochemical studies, two major hypotheses have been proposed. One group of researchers supports the idea that ASPS shows myogenic differentiation, while the other group opposes the idea. This confrontation is essentially one between a group that believes in the immunohistochemically demonstrated presence of desmin in ASPS and a group that denies it. In the present study we detected desmin in 6 of 10 formalin-fixed paraffin sections (although there were differences due to the use of five commercially available types of anti-desmin antibodies). When acetone-fixed paraffin sections and periodate-lysin-paraformaldehyde (PLP)-fixed frozen sections were used in one and three cases, respectively, they were found to be desmin positive, regardless of the type of antibody. The consistent positivity for all anti-desmin antibodies in the cases treated with acetone or PLP is very suggestive of a myogenous origin of ASPS. It is important to take into consideration the fact that formalin-fixed paraffin sections are not very suitable for immunohistochemical study of desmin.

Paracrystalline inclusions in metaplastic ciliated cells of the human gastric mucosa. An ultrastructural study

Unusual electron-dense paracrystalline inclusions were found in metaplastic ciliated cells in the stomachs of three Japanese male patients with gastric carcinoma. These patients had not been given antitumour drugs before surgery and ethrane (enflurane) was used as the anaesthetic. Ciliated cells in the gastric mucosa are found not infrequently in the pyloric glands in association with intestinal metaplasia in elderly Japanese patients. Paracrystalline inclusions were found only in the ciliated cells and never in any other types of gastric mucosal cell. These inclusions were located in the apical portion of the ciliated cells in intimate association with the basal bodies. They consisted of twisted strings about 27 nm wide with a regularly repeated spacing of about 30 nm. On highly magnified electron micrographs, granules about 4 nm in diameter were detected. These paracrystalline inclusions have never been reported previously, although their location in ciliated cells and their morphological characteristics suggest an intimate relationship with the ciliogenesis of metaplastic ciliated cells in the human stomach.

Alveolar soft-part sarcoma. A clinico-pathologic study of half a century

In the period from 1923 to 1986 our pathologists examined pathologic material from 102 patients with alveolar soft-part sarcoma (ASPS). Followup clinical data is available for 91. Median followup is 7 years (range 1 month to 27 years). Local recurrence was only found if residual disease was left at the time of the original excision. Survival in those patients who presented without metastases was 77% at 2 years, 60% at 5 years, 38% at 10 years and 15% at 20 years (median 6 years). No survival advantage could be demonstrated for patients who received chemo and/or radiotherapy, although numbers are small and staging not uniform. An evaluation by electron microscopy and immunohistochemistry cannot confirm recent claims that ASPS is a muscle tumor. ASPS is an unusual neoplasm; the primary therapeutic option is aggressive surgical excision. Survival even with the development of metastases can be long.

What's new in dermatopathology

This article reviews the recent English language literature on dematopathology, with an emphasis on publications appearing between January 1986 and July 1987. Immunohistochemistry continues to grow in importance as a diagnostic as well as a research technique. The advent of in situ deoxyribonucleic acid hybridization technology has raised diagnostic accuracy to a new level; it has already proved valuable in the diagnosis of certain viral infections. Areas that have received particular attention include phenotypic characteristics of lymphomas and lymphoma-like conditions, congenital melanocytic nevi and malignant melanoma, neuroendocrine carcinoma and other small cell tumors of the skin, sweat gland carcinomas, and eosinophil and its associated diseases, and unusual infectious diseases involving the skin.