Immunohistochemical study of granular cell tumours. Demonstration of neurone specific enolase, S 100 protein, laminin and alpha-1-antichymotrypsin

Congenital Epulis: A Case and Review of the Literature

Congenital epulis is an unusual benign oral mucosal lesion in newborns with no tendency to recur after excision. The histogenesis of the lesion is unknown, but it is believed to be of mesenchymal origin. We describe a case of congenital epulis (20×10 mm) in the mandibular gingiva of a newborn. The mass, which was smooth-surfaced and pedunculated with a healthy color, was surgically removed at 5 months post-birth. Histologically, the tumor consisted mainly of large eosinophilic granular cells. Immunohistochemical studies revealed intense staining for vimentin, STRO-1, and CD44, suggesting that it was derived from mesenchymal cells. The literature and immunohistochemical profile of congenital epulis are also discussed.

Granular Cell Tumor: An Immunohistochemical Study

Aims and background

Granular cell tumor, usually a benign neoplasm, has been the object of many studies because of its uncertain histogenesis and based on many immunohistochemical and ultrastructural studies it has been suggested that it originates from the Schwann cell. Our recent observation that granular cell tumor is positive with PG-M1, a new anti-macrophage monoclonal antibody, led us to further investigate the immunophenotypic profile of the tumor.

Study design

We studied 11 granular cell tumors using a panel of 20 antibodies, 13 monoclonal and 7 polyclonal.

Results

The immunohistochemical study showed in all cases a constant diffuse positivity for S-100 protein, neuron-specific enolase, vimentin, KP1 and PG-M1, as well as occasional and focal positivity for alpha-1-antitrypsin, alpha-1-antichymotrypsin and lysozyme.

Conclusions

The immunophenotypic profile constantly observed could be the expression, on one hand, of the neuroectodermic nature of the neoplasm, proven by positivity for S-100 protein, neuron specific enolase and vimentin, and on the other could be the expression of the phagocytic activity of the tumor cell, proven by positivity for KP1 and PG-M1 antibodies and also by the presence of numerous phagolysosomes.

Gastric Epithelioid Stromal Tumor (Leiomyoma) With Granular Changes

A unique case of gastric epithelioid stromal tumor (leiomyoma) demonstrating granular changes is reported. Microscopically, the tumor was composed of polygonal or fusiform cells with a coarse, granular eosinophilic cytoplasm, focally admixed with fascicles of spindle-shaped cells. A marked lymphoid infiltrate forming follicles was also a characteristic finding. Immunohistochemically, these cells were positive for alpha-smooth-muscle actin, HHF-35 (muscle-specific actin), and NKI/C3 but negative for desmin, S100 protein, vimentin, lysozyme, and Mac-387. This case demonstrates that granular cell changes and prominent lymphoid aggregates are not limited to gastric stromal tumors with neural differentiation.

Neurogenic polyps of the gastrointestinal tract: a clinicopathologic review with emphasis on differential diagnosis and syndromic associations

Primary neurogenic gastrointestinal polyps are encountered relatively frequently in routine pathology practice. They encompass a variety of neoplastic entities with clinical, morphologic, and molecular features that reflect the diversity of neural elements within the gastrointestinal system. Although most are benign and encountered incidentally, accurate diagnosis may have important clinical implications because of the associations of certain neurogenic polyps with familial syndromes or other conditions. We review the pathology of these polyps with an emphasis on the diagnostic challenges that they pose and on newly described subtypes.

Multifocal Synchronous Granular Cell Tumors of the Gastrointestinal Tract

Granular cell tumors (GCT) are rare and unusual tumors, which are usually benign and asymptomatic. Only 5-10% of cases involve the gastrointestinal tract, most commonly as singular, non-cancerous lesions in the esophagus. We report a rare case of symptomatic, multifocal, synchronous GCT involving the esophagus, stomach, and cecum.

Neurogenic tumors of soft tissue

Neurogenic tumors are an uncommon yet important category of soft tissue tumors in children and adolescents because of their frequent association with various genetic syndromes. The heterogeneous cellular composition of the peripheral nerve and the wide metaplastic capacity of the neural crest and its derivatives generate a variety of neoplasms with neurogenic differentiation. This article reviews the clinicopathologic features and differential diagnosis of neurogenic tumors in the first two decades of life, and highlights use of selected ancillary methods for diagnosis.

Congenital granular cell epulis presents an immunohistochemical profile that distinguishes it from the granular cell tumor of the adult

Congenital granular cell epulis (CGCE), a rare benign lesion arising from the mucosa of the alveolar ridges of the jaws in newborns, has a clinical course characterized by lack of further growth after birth. Histomorphologically, it resembles a granular cell tumor (GCT) of the adult. The histogenesis of this lesion is unclear. We submitted a series of five CGCEs to a large panel of antibodies in order to trace the origin of the constituent granular cells. The resultant immunohistochemical profile showed positivity of these cells to vimentin, NKI/C3, and PGP9.5. This does not confirm any particular cell type for the histogenetic origin of CGCE but may rather reflect a local metabolic or reactive change, providing supporting evidence that the lesion is of a non-neoplastic nature. In addition, the granular cells were non-reactive for S-100, NGFR/p75, and inhibin-alpha, which further contributes to the distinction between a CGCE and the adult GCT.

Granular Cell Tumour Affecting the Left Vocal Cord in a Dog

Granular cell tumours (GCTs) have been described in human vocal cords, but not in those of the dog. A single polyp in the left vocal cord, associated with laryngeal oedema and monolateral hyperplasia of the tonsil, was observed endoscopically in a 6-year-old male dog. Cytologically, the mass was characterized by well-defined polygonal cells, with granular cytoplasm and an eccentric nucleus. Histologically, the mass showed sheets of globoid to polygonal cells, filled with numerous diastase-resistant, periodic acid-Schiff-positive granules, and scanty stroma. Ultrastructurally, the granules were represented by heterogeneous lysosomes of variable size, suggesting a diagnosis of GCT. As reported in man, hyperplasia of the laryngeal and tonsillar epithelium and the presence of foci of pearl-like epithelial cells, mimicking invasive squamous cell carcinoma, were observed. Immunohistochemical examination revealed labelling of neoplastic cells for S-100 protein, CD68, collagen IV, and, focally, for glial fibrillary acidic protein, neuron-specific enolase and vimentin. These findings suggested a Schwann cell origin of the GCT.

Sonographic and mammographic appearances of granular cell tumors of the breast with pathological correlation

PURPOSE

To describe the sonographic and mammographic appearance of granular cell tumors (GCTs) of the breast in 6 patients with pathological correlation.

METHODS

A search was conducted of the cyto-histopathological database in a single institution from 1990 to 2004 for breast lesions given the diagnosis of GCT of the breast. Six patients with GCT of the breast who underwent mammographic or sonographic examination or both before surgery were included in this study.

RESULTS

The mammographic features of GCT of the breast were indeterminate in most patients, often presenting as an isodense mass with indistinct or spiculated margins. Calcifications were not a feature. The sonographic features of GCT of the breast mimicked carcinoma, including heterogeneous echotexture, indistinct margins, and hypervascularity. Hyperechogenicity was noted in 5 of 7 (71%) GCTs in this series. The cytomorphological features of GCT included sheets of large granular cells intersected by arborizing thin-walled blood vessels. The cells had round to oval nuclei, inconspicuous nucleoli, and abundant, ill-defined granular cytoplasm.

CONCLUSIONS

Breast imagers should be aware that GCT of the breast is an uncommon differential in a minority of neoplasms that can be mistaken for breast cancer.

Granular cell tumor of the intrapancreatic common bile duct: one case report and review of the literature

A granular cell tumor (GCT) in a 39-year-old white man is reported. It was localized in the intrapancreatic part of the common bile duct and caused obstruction of the bile downflow. The patient underwent radical surgical procedures because a malignant tumor was clinically suspected. Macroscopically, the tumor appeared as a duct stricture caused by diffuse infiltration of neoplastic cells in the walls. In the cytoplasm smaller and larger PAS-positive granules were present and constantly reactive to S-100 and NSE antibodies. Ultrastructurally, cytoplasmic granules appeared as membrane-bound vacuoles of variable size and shape containing debris, disrupted mitochondria, and myelin figures. No basal lamina around cell cytoplasm was observed. GCTs are relatively uncommon soft tissue tumors usually presenting in the skin and subcutaneous tissues or tongue. The prognosis in any location is quite good, but very rare malignant GCTs (1-2%) are documented. Complete excision reduces the risk of recurrence. Accurate operative diagnosis seems to be critical when the tumors are located in the intrapancreatic common bile duct as in this reported case. Gastro-pancreatico-duodenectomy is too radical a procedure for such a benign lesion and additional assessments and investigations are recommanded before such an extensive radical surgery.

Granular cell tumor of the trachea in pregnancy: a case report and review of literature

OBJECTIVES/HYPOTHESIS

The objectives were to present a case report of a woman with recurrent disease during consecutive pregnancies and to discuss the diagnosis and management of granular cell tracheal tumors, with particular attention to pregnancy and hyperestrogenic states.

STUDY DESIGN

Case report and literature review.

METHODS

A Medline search and comprehensive review of literature to assess all cases of granular cell tumors of the trachea were compared and collected, with particular attention to individual cases of pregnancy or cases related to the hyperestrogenic state.

RESULTS

Thirty-two cases of granular cell tumors of the trachea were found. Only a few cases related to the hyperestrogenic state were obtained. The case report describes a woman with recurrent disease in subsequent pregnancies during the later stages of pregnancy.

CONCLUSION

Few cases of granular cell tumors of the trachea have been reported, with even fewer being pregnancy related. The diagnosis and management of these tumors include careful attention to patient symptoms and airway management.

Polypoid S-100-negative granular cell tumor of the oral cavity: a case report and review of literature

This is a report of a case of an S-100-negative polypoid granular cell tumor arising in the lower lip of a 4-year-old patient that may represent the entity primitive polypoid granular cell tumor. Unlike the usual granular cell tumors arising in the tongue or buccal mucosa, such lesions are not S-100 positive and can exhibit mitoses and cytologic atypia, features that may suggest a low-grade mesenchymal malignancy necessitating aggressive therapy. However, this is in fact a nonaggressive neoplasm that is not associated with significant morbidity and therefore should be treated with simple excision.

Expression of inhibin-alpha by granular cell tumors of the gallbladder and extrahepatic bile ducts

This is the first report of inhibin-alpha expression in granular cell tumors. A Medline search of the literature revealed no case reports of granular cell tumors in any location of the body being tested for inhibin-alpha immunohistochemically, by enzyme-linked immunosorbent assay, by radioimmunoassay, or by immunoprecipitation. Seventeen cases of previously diagnosed granular cell tumors of the gallbladder and extrahepatic bile ducts with hematoxylin and eosin-stained sections, and S-100 protein immunostain were retrieved from the archives of the Armed Forces Institute of Pathology. All cases were reviewed for diagnostic accuracy and then immunostained for inhibin-alpha (with endogenous biotin blocking). All 17 (100%) cases were diffusely positive for inhibin-alpha immunostain. Previous studies of inhibin-alpha-positive lesions reported in the literature include sex cord stromal tumors (granulosa cell tumors, luteinized thecomas, Leydig cell tumors), placental and gestational trophoblastic lesions, and adrenal cortical tumors. This study adds the granular cell tumor to the list of inhibin-positive lesions and should prove helpful in differential diagnosis of these lesions.

Granular cell lesions in the distal female reproductive tract of aged Sprague-Dawley rats

During the review of a rat carcinogenicity study, a spectrum of granular cell lesions was recognized in the distal female reproductive tract. To verify the diagnoses, cell populations of nine granular cell alterations of the cervix or vagina were characterized immunohistochemically and four were evaluated ultrastructurally. Immunoreactivity was demonstrated in 8/9 cases with S100 protein, 6/9 cases with neuron-specific enolase, and 7/9 cases with Leu-7. Granular cells were negative for smooth muscle-specific actin and calretinin. The immunohistochemical profile of these lesions was similar to that previously reported in other species, including humans. Ultrastructurally, as expected many lysosomal bodies were present in the cytoplasm of granular cells in all specimens evaluated. Based on the detailed evaluation of a series of lesions, we adopted the following diagnostic criteria and nomenclature for the granular cell changes of the female reproductive tract of rats. Granular cell aggregates were non-space-occupying lesions composed of clusters of typical granular cells. Benign granular cell tumors were space occupying lesions that typically contained prominent interstitial collagen and were either discrete masses or were difficult to discern from the surrounding tissues. Some benign tumors also contained foci of spindle cells with decreased granularity. Malignant tumors exhibited pleomorphism and an increased nucleus: cytoplasm ratio morphologically but had the same biologic behavior as the benign tumors. We applied these diagnostic criteria during the review of controls from 9 carcinogenicity studies. Up to 23% of control females in those carcinogenicity studies had granular cell lesions that could be classified into one of the three categories. Granular cell lesions appear to be common in the cervix/vagina of the Sprague-Dawley rat, and tumors may develop from granular cell aggregates.

A case of atypical granular cell tumor of the neurohypophysis

A case of granular cell tumor (GCT) arising in the neurohypophysis of a 63-year-old woman is reported. The tumor consisted of ovoid, polygonal or spindle-shaped cells in a sheet-like or fascicular arrangement. Its abundant cytoplasm contained granules positive for diastase-resistant periodic acid-Schiff reaction. Ultrastructurally, the tumor cells contained numerous polymorphic lysosomes of various densities. Immunohistochemically, the tumor cells were positive for S-100 protein, glial fibrillary acidic protein and Leu7, suggesting that the tumor originated from pituicytes that were thought to be modified astrocytes in the neurohypophysis and its stalk. The granular cells showed nuclear atypia, pleomorphism and increased mitotic activity. Therefore, the present tumor was considered as a histologically atypical GCT. Interestingly, proliferating cell nuclear antigen, Ki-67 and p53 were stained in a few tumor cells of this case. These findings indicate that the present tumor had a malignant potential.

Granular cell traumatic neuroma: a lesion occurring in mastectomy scars

BACKGROUND

Granular cell changes can be observed in a variety of benign and malignant tumors, and are seen more commonly in granular cell tumors, which in about 5% of cases develop in the breast. Granular cells also have been observed in sites of previous trauma, such as surgery, and are found to be inflammatory reactions of histiocytic origin.

METHODS AND RESULTS

We investigated, morphologically and immunohistochemically, 2 granular cell lesions occurring in mastectomy scars after surgery for carcinoma. Both lesions were composed of strands and nests of large granular cells, haphazardly set in a background of fibrous tissue, with sparse inflammatory infiltrates. Several tortuous hypertrophic nerve bundles were also embedded in the fibrous tissue. A few of these nerve bundles showed degenerative changes and contained granular cells. Immunohistochemically, granular cells were positive for S100 protein, neuron-specific enolase, vimentin, and CD68 antigen.

CONCLUSIONS

We consider these proliferative lesions of peripheral nerves to have the features of both granular cell tumor and traumatic neuroma. These cases indicate that traumatic neuroma can undergo extensive granular cell changes and constitute a previously unrecognized entity, which we provisionally label granular cell traumatic neuroma. Granular cell traumatic neuroma has to be taken into consideration when evaluating lesions occurring at mastectomy scars and should be differentiated from malignant tumors with granular cells, such as apocrine carcinoma and alveolar soft part sarcoma.

Malignant granular cell tumor of soft tissue: diagnostic criteria and clinicopathologic correlation

Seventy-three cases of malignant, atypical, and multicentric granular cell tumors of soft tissue were studied to clarify criteria for malignancy and prognostic factors. Six histologic criteria were assessed: necrosis, spindling, vesicular nuclei with large nucleoli, increased mitotic activity (> 2 mitoses/10 high-power fields at 200x magnification), high nuclear to cytoplasmic (N:C) ratio, and pleomorphism. Neoplasms that met three or more of these criteria were classified as histologically malignant; those that met one or two criteria were classified as atypical; and those that displayed only focal pleomorphism but fulfilled none of the other criteria were classified as benign. Hence, 46 cases were classified as histologically malignant, 21 as atypical (3 were multicentric), and 6 as benign (all were multicentric). The patients with benign multicentric and atypical granular cell tumors had no metastases and there were no tumor deaths. In contrast, 11 of 28 patients (39%) with malignant granular cell tumor with follow-up information died of disease at a median interval of 3 years; 8 of 28 (29%) were alive with disease, and 9/28 (32%) were disease free (median intervals, 2 and 7 years, respectively). There were local recurrences in 9 of 28 malignant cases (32%) and metastases in 14 of 28 (50%) (median intervals, each 2 years). Forty-eight cases were studied immunohistochemically; 100% expressed vimentin, 98% S-100 protein, 98% neuron-specific enolase, 69% CD57, and 65% CD68. Alpha-smooth muscle actin, desmin, epithelial membrane antigen (EMA), cytokeratins (with CAM 5.2 and KL-1), chromogranin, and HMB45 were not detected. The proliferative index with Ki67 (MIB 1) was 10-50% in 14 of 25 malignant tumors (56%), and immunostaining for p53 was detected in 50% or more of tumor cells in 17 of 25 (68%); both of these factors were statistically significant with regard to the histologic classification as benign, atypical, or malignant. Ultrastructural examination of 13 benign, atypical, and malignant granular cell tumors showed engorgement of the cytoplasm with complex granules and lysosomes, as well as Schwannian features. By flow cytometric DNA analysis, two of six malignant tumors were aneuploid, two were hyperdiploid, and two were diploid. One atypical tumor was aneuploid and all 11 benign tumors were either diploid (9 cases) or hyperdiploid (2 cases). Statistically significant adverse prognostic factors with regard to survival included local recurrence, metastasis, larger tumor size, older patient age, histologic classification as malignant, presence of necrosis, increased mitotic activity, spindling of tumor cells, vesicular nuclei with large nucleoli, and Ki67 values greater [corrected] than 10%. This study defines clinical and morphologic criteria for malignancy in granular cell tumors and shows that malignant granular cell tumor is a high-grade sarcoma with a high rate of metastases and a short survival.

Immunohistochemical study on histogenesis of congenital epulis and review of the literature

Congenital epulis is a very rare lesion found only in newborn infants. This tumor is multiple in about 10% of reported cases, rarely with the simultaneous involvement of the maxilla and mandibula, as in this article. In the presented case, light microscopy demonstrated large eosinophilic granular cells arranged in solid nests that are separated by thin fibrovascular areas. The tumors in the maxilla and mandibula were investigated with a panel of polyclonal and monoclonal antibodies, and using immunoperoxidase methods on formalin-fixed, paraffin-embedded sections. Immunohistochemical studies revealed strong and diffuse cytoplasmic staining for neuron specific enolase and vimentin. However, all other reactions were negative. These results suggest that the congenital epulis may be derived from uncommitted nerve-related mesenchymal cells.

Granular cell tumor expressing myogenic markers in the prostate

A granular cell tumor in the prostate of a 72 year old male is reported. The tumor nest was composed of large polygonal tumor cells, possessing cytoplasmic eosinophilic granules which were positive with PAS stain and resistant to diastase digestion. Immunohistochemically, most tumor cells were strongly positive with anti-alpha-smooth muscle actin and -neuron specific enolase antibodies. Only a few scattered tumor cells were reacted with anti-S-100 protein antibody. These findings might suggest smooth muscle differentiation of this case, and provide an additional insight into the histogenesis of granular cell tumors, especially in their heterogeneity.

Congenital epulis and granular cell tumor: a histologic and immunohistochemical study

OBJECTIVES

Although it is now reasonably certain that granular cell tumors derive from Schwann cells, the histogenesis of congenital epulis, which is largely isomorphic with granular cell tumor, remains unclear. A study was undertaken to compare the immunophenotype of these tumors with particular emphasis on the expression of matrix proteins and macrophage markers because such information is not available in the literature.

STUDY DESIGN

Four granular cell tumors and two congenital epulis were immunostained with a panel of 29 antibodies. Two congenital epulis and one granular cell tumor were investigated by electron microscopy, the latter also by immunoelectron microscopy.

RESULTS

Many similarities in immunostaining were found, for example, both tumor types were CD68+, Ki-M1P+, lysozyme-, vimentin+, fibronectin+, laminin+, lectin PHAE+, and lectin WGA+. However, differences were also noted, for example, granular cell tumor was always S100 protein+, but only one congenital epulis case was reactive (weak reactivity after microwave treatment), and staining with the proliferation markers anti-proliferating cell nuclear antigen and MIB 1 was found only in congenital epulis. Both tumor types exhibited pericellular and diffuse cytoplasmic staining for fibronectin and laminin.

CONCLUSIONS

The hypothesis that congenital epulis and granular cell tumor would exhibit similar reactivity for macrophage markers was confirmed: both were reactive with anti-CD68 and Ki-M1P and nonreactive with MAC387, anti-lysozyme, and 3A5. Intracytoplasmic staining for fibronectin and laminin, which has not been described previously in these tumors, appears to be a characteristic feature common to both tumors. This finding suggests that there could be a disturbance of synthesis and secretion of extracellular matrix proteins or a derangement of their receptor systems. This theory could be supported by the finding of intracytoplasmic CD49e-positive material in two cases.

Expression of immunoreactivities to 75 kDa nerve growth factor receptor, trk gene product and phosphotyrosine in granular cell tumors

Nineteen granular cell tumors (GCT) of adults, two congenital granular cell epulides and five epulides fibrosae were immunohistochemically examined to detect the expression of 75 kDa nerve growth factor receptor (NGFR), trk gene product, phosphotyrosine (PT), protein gene product 9.5 (PGP9.5) and S-100 protein. The NGFR-immunoreactivity (IR) and trk gene product-IR were expressed on almost all granular cells of GCT. PT-IR was also demonstrated on granular cells of all GCT examined, although the frequency of positive cells was low. Congenital granular cell epulides and epulides fibrosae were negative for NGFR-IR, trk gene product-IR and PT-IR. S-100 protein was localized in granular cells of adult GCT but not in the granular cells of congenital epulis. On the other hand, PGP9.5 was detected in granular cells of both conditions and in fibroblastic cells of epulis fibrosa. The present results further indicate that GCT is of peripheral nerve Schwann cell origin, while the congenital granular cell epulides are not of neural origin. NGFR and trk gene product expressed on GCT seems to be functional in terms of phosphorylation of the tyrosine residue in the receptor or downstream protein in signal transduction.

Immunohistochemical study of granular cell tumors and granular pituicytes of the neurohypophysis

Six neurohypophysial GCTs and 31 normal neurohypophysis were studied by immunohistochemical techniques. The latter were grouped into A (< 5 yr old), B (30-49 yr), and C (> 70 yr). GCTs were all labeled by PNA, and some showed reactivity for S-100 protein, AAT, AAC, and cathepsin B. In addition, some were oxytocin- and vasopressinpositive. Unlike extracranial GCTs, neuron-specific enolase, myelin basic protein, and vimentin were not detected. Glial fibrillary acidic protein, keratin, and desmin were also not observed. In contrast, a few cells of the normal neurohypophysis showed immunoreactivity for AAT, AAC, cathepsin B, and PNA, similar to the cells of GCT. These cells tended to increase in number with age: group A showed fewer cathepsin B-positive cells than groups B and C (p < 0.001). These results show that neurohypophysial GCTs have some features that differentiate them from extracranial GCTs, for which a Schwann cell origin has been proposed by many authors. It was concluded that neurohypophysial GCT may originate from the cells that showed similar immunoreactivity, the "granular" pituicytes. Our results also support the hypothesis that neurohypophysial GCTs are an age-related metabolic disorder of lysosomes rather than true neoplasms.Endocr Pathol 4:140-145, 1993.

Investigation into the histogenesis of congenital epulis of the newborn

Five previously unreported cases of congenital epulis of the newborn are presented. All five cases were on the anterior maxillary alveolar ridge. Four were removed at 2 days of age and one at 7 weeks. Light microscopy demonstrated large eosinophilic granular cells within vascular fibrous connective tissue. Immunohistochemical studies revealed a positivity for vimentin and neuron specific enolase. Cytogenetic evaluation performed on one case was normal. Estrogen and progesterone receptors were absent in the one case so studied. Electron microscopy demonstrated tumor cells that were filled with autophagosomes. Cellular organelles were significantly reduced and inversely related to the number of cytoplasmic autophagosomes. Many of the autophagosomes contained collagen precursors. Poorly formed junctional complexes were seen. Occasional tumor cells demonstrated long processes that contained contractile microfilaments, pinocytosis, and areas of exocytosis. These studies suggest the tumor cells represent early mesodermal cells that express pericytic and myofibroblastic features that undergo cytoplasmic autophagocytosis.

Histologic and immunohistochemical studies of granular cell tumors in seven dogs, three cats, one horse, and one bird

In a retrospective study, granular cell tumors in six dogs (Nos. 1-6), three cats (Nos. 1-3), one horse (No. 1), and one cockatiel (Nymphicus hollandicus) (No. 1) and a meningioma with a granular cell component in one dog (No. 7) were examined histologically and immunohistochemically. These tumors were identified by histologic examination of surgical biopsy specimens, except in the horse, in which the tumor was an incidental finding at necropsy. These diagnoses were initially made by more than one pathologist. Five of the six granular cell tumors in the dogs were in the oral cavity; one of these was in the maxillary gingiva of a 6-month-old puppy. The tumors in the cats were located in the tongue, vulva, and digit. The tumor in the horse was in the lung, and the tumor in the cockatiel was in the periocular tissue. Histologically, all granular cell tumors were characterized by oval to polygonal cells of various sizes. The cells had abundant, pale, eosinophilic cytoplasm with distinct intracytoplasmic granules, distinct cell margins, and mostly central nuclei. In the dogs, the gingival tumor had a large amount of collagen tissue, the tumor in the tongue had dilated blood vessels, and the maxillary tumor in the puppy was more cellular than the other tumors. The tumors in the cats were more anaplastic than the other tumors; one, located in the digit, was considered malignant. The granules in all of the tumors stained with periodic acid-Schiff and were diastase resistant. On staining with Luxol fast blue, the granules of all tumors stained different shades of pink, with the exception of the tumor in the tongue of a cat, which stained bluish green. Immunocytochemically, all tumors except the tumor in the cockatiel reacted against antibodies to vimentin. The granular cell tumor in the lung of the horse and the intracranial meningioma in a dog reacted to the antibody S-100 protein; the tumor in the horse reacted to neuron-specific enolase; tumors in two dogs (gingiva and skin) reacted to L-antitrypsin, and the maxillary tumor also reacted to lysozyme; the malignant tumor in the digit of a cat and the periocular tumor in the cockatiel reacted to muscle common actin and actin; the tumor in the cockatiel also reacted to desmin. Results of these immunocytochemical studies suggest that granular cell tumors, like tumors composed of rhabdoid cells, clear cells, and oncocytes, can have similar morphologic features but be of different cellular origins.

Granular cell tumor in differential diagnosis of tumors of the breast. The role of fine needle aspiration cytology

The granular cell tumor (GCT) represents a rare but important lesion in the differential diagnosis of breast tumors. Since this generally benign tumor may be misdiagnosed as malignant in clinical investigation, mammography, sonography, and even in frozen sections, a preoperative diagnosis is of utmost importance. Two cases illustrate that fine needle aspiration cytology (FNAC) may be the method of choice in achieving a correct preoperative diagnosis. The histogenesis of GCT is examined by means of immunohistochemical stainings. The results confirm that this tumor arises from the peripheral nerve tissue. Most likely the Schwann cells and not the nerve cells constitute the origin of GCT.

Immunohistochemical and ultrastructural investigation of granular cell tumours in dog, cat, and horse

Six canine, one feline and one equine granular cell tumours (GCTs) were investigated electron microscopically and immunohistochemically. The tumours were tested for reactivity with monoclonal antibodies against vimentin and desmin and with polyclonal antibodies against cytokeratin, S-100 protein, glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE). All GCTs were characterized by their PAS positive cytoplasmic granules in light microscopy, which in electron microscopy appeared as lysosome-like granules. In each case two canine GCTs were stained by the antibody against cytokeratin, vimentin and S-100 protein. Cells of the equine GCT showed reactivity with the antiserum against S-100 protein. In the feline GCT no reactivity with any of the antibodies tested was observed. These differences of the immunohistochemical reactions of GCTs suggest a nonuniform histogenesis of GCTs in domestic animals. The reactivity of the tumour cells with the antiserum against NSE is discussed.

Granular cell tumour of the breast

Eight cases of benign granular cell tumour of the breast are reported. Seven patients were women and one was male. The age at the time of the excision ranged from 17 to 73 (average 40.1) years. All tumours were positive for S-100 protein and negative for keratin, myoglobin and gross cystic disease fluid protein. In two cases ultrastructural studies revealed findings identical to those in the previously reported cases of granular cell tumours. None of these cases were diagnosed preoperatively. In six cases the clinical and mammographic findings, and in one case the frozen section, led to an erroneous diagnosis of malignancy. The clinico-pathological features of the cases are delineated in order to draw attention to a benign condition which closely simulates malignancy.

A desmoplastic granular cell tumour of the oral cavity: report of a case

A case of granular cell tumour of the buccal mucosa demonstrating marked desmoplasia is presented. The bulk of the tumour is composed of dense collagenous stroma, which surrounds isolated nests of tumour cells. Since the histomorphologic appearance of this variant is different from that usually seen in this lesion, the diagnosis is supported by immunohistochemical demonstration of S-100 and Vimentin in the tumour cells. The authors believe that this case represents the first report of a desmoplastic granular cell tumour of the oral tissues.

Immunohistochemical study of granular cell tumors of the neurohypophysis

Six granular cell tumors (GCT) of the neurohypophysis were studied by immunohistochemical techniques. They were all labeled by peanut lectin (Arachis hypogaea) and three showed reactivity for S-100 protein. Unlike extracranial GCT, neuron specific enolase (NSE), myelin basic protein (MBP) and vimentin were not detected in the tumor cells. Glial fibrillary acidic protein (GFAP), keratin and desmin were also not observed. On the other hand, some showed reactivity for alpha-1-antitrypsin (AAT), alpha-1-antichymotrypsin (AAC) and cathepsin B. These results suggest that neurohypophysial GCT have some features different from extracranial GCT and that they may not be derived from Schwann cells.

Granular cell tumor of a digital nerve

Granular cell tumor is an infrequently encountered albeit not rare neoplasm considered to be of neuroectodermal origin. An example of a benign granular cell tumor originating within a digital nerve is presented. The authors employed routine light microscopic techniques and immunostaining which demonstrate features of the granular cells reflecting structural and functional characteristics of Schwann's cells and support neuroectodermal derivation. Granular cell tumor is ubiquitous in location but occurs more frequently in tongue, skin and subcutaneous tissue. Clinical features are not specific, and a histologic evaluation is required for diagnosis. Circumscription and lack of cellular pleomorphism define a benign process. However, irrespective of its histologic appearance, the biologic potential is uncertain. Complete excision suffices as treatment for benign tumors.

Granular cell brain tumors of the laboratory rat: an immunohistochemical approach

We have studied paraffin-embedded specimens of 17 rat granular cell brain tumors (GCBT) from four long-term drug safety carcinogenicity studies by peroxidase-antiperoxidase (PAP) immunohistochemistry with either polyvalent or monoclonal antibodies against glial fibrillary acidic protein (GFAP), S-100 protein (S-100), Leu-7 epitopes, vimentin (VIM), keratin, desmin, and myelin basic protein. We have found that 9 of the 17 GCBT contained GFAP-positive, S-100-positive, and VIM-positive astrocytes, while GFAP-positive and VIM-positive granular cells were observed in 5 of these 9 tumors. Our findings indicate that astroglial cells are involved in rat GCBT and suggest that an astrocytic origin should be considered for these neoplasms.

Immunohistochemical study of congenital gingival granular cell tumor (congenital epulis)

The congenital gingival granular cell tumor (CGGT) or congenital epulis is a rare lesion of unknown origin found only in newborn infants. The tumor consists mainly of large eosinophilic granular cells arranged in solid nests that are separated by thin fibrovascular areas. In addition, there are some spindle-shaped cells and medium-sized polygonal cells (so-called interstitial cells) among the neoplastic granular cells. Three CGGTs were investigated with a panel of poly- and monoclonal antibodies, using immunoperoxidase methods on formalin fixed paraffin embedded sections. Neoplastic granular cells of these three cases show cytoplasmic staining for neuron-specific enolase (NSE) and vimentin. However, all other reactions were negative. Our results suggest that the lesion may be derived from uncommitted nerve-related mesenchymal cells. On the other hand, interstitial cells show strong S-100 protein-, cytokeratin-, vimentin-, and NSE-immunostainings, and these cells are consistent with neuroendocrine nature. The presence of a biphasic cell population with granular cells and interstitial cells must be considered the main immunohistochemical feature.

Characterization of glycoconjugates found in granular cell tumors, with special reference to keratan sulfate

Nine granular cell tumors (GCTs) were studied using the immunoperoxidase technique with a mouse monoclonal antibody to keratan sulfate and a polyclonal antibody to S-100 protein. Various lectins and basic dye stains were also employed. Schwannomas benign and a malignant, a neurofibroma, a leiomyoma, two examples of nevus pigmentosus and a congenital epulis were similarly examined to compare the histochemical reactivities. Tumor cells of all the GCTs reacted intensely with the antibodies to keratan sulfate and S-100 protein. Peripheral nerve bundles and other neurogenic tumors showed stained for S-100 protein but not for keratan sulfate. Basic dye stain indicated the presence of sulfated glycoconjugates in GCTs. Lectin stains demonstrated that GCTs were rich in glycoconjugates but the reactivity patterns for 14 lectins differed between GCTs and normal tissue components. None of the lectins used in this study was specific for GCTs. These results indicate that GCTs contain abundant glycoconjugates and that the monoclonal antibody to keratan sulfate may be an immunohistochemical marker for GCT.

Immunoreactivity of granular cell lesions of skin, mucosa, and jaw

Granular cell lesions from many different sites share similar light and electron microscopic features. Immunologically, however, these lesions do not appear to be a homogenous group. This study determines the extent of immunologic heterogeneity of granular cell lesions from a wide variety of sites in skin, mucosa, and jaw. Thirty-one granular cell lesions (26 granular cell tumors [GCT] and five other granular cell lesions) from 18 different sites were evaluated immunohistochemically for keratins, vimentin, desmin, muscle actin, ACT, HLA-DR, and S-100 protein. Paraffin-embedded sections were utilized with an avidin-biotin complex immunoperoxidase technique. Except for ameloblastomas, all lesions were negative for keratin and positive for vimentin. All lesions were negative for desmin and actin. Positive ACT reactivity was found in one of seven GCT of tongue, a colonic lesion, a nose lesion, and a granular cell ameloblastic fibroma. All lesions were positive for HLA-DR except a few in which fixation appeared inadequate. S-100 immunoreactivity was found in all lesions except the congenital epulis, a GCT of the skin of the nose, a colonic lesion, and the odontogenic tumors. The antigenic profile of GCT of skin and mucosa is consistent with Schwann cell origin. However, some GCT and other granular cell lesions appear to be derived from macrophages, epithelial cells, or other cells. The expression of HLA-DR by granular cells is believed to be unrelated to cellular origin but rather to some common immunologic function.

Granular cells in odontogenic and non-odontogenic tumours

Granular cells can occur in various odontogenic and non-odontogenic tumours. 5 granular cell lesions, one granular cell ameloblastoma, one so-called granular cell ameloblastic fibroma and three granular cell tumours were examined immunohistochemically for the intermediate filaments cytokeratin, vimentin, desmin, neurofilaments and the neural markers NSE and S-100 protein. The granular cell tumors (granular cell myoblastoma) showed positive staining for vimentin and S-100 protein. Only vimentin could be demonstrated in the granular cells of the so-called granular cell ameloblastic fibroma, whereas the granular cell ameloblastoma showed positive staining only for cytokeratin. A positive reaction with S-100 protein was not found in any of the odontogenic tumours. In our opinion the mesenchymal odontogenic granular cell is a fibroblast, whereas the epithelial granular cell is derived from enamel epithelium. The term "granular cell ameloblastic fibroma" is a misnomer, as a number of these tumours are probably central odontogenic fibromas exhibiting granular cell transformation.

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.

S-100 immunoreactivity in primary and metastatic carcinoma of the breast: a potential source of error in immunodiagnosis

Immunoreactivity for S-100 protein, typically a marker for malignant melanoma and neural-derived tumors, was observed in neoplastic cells of 57 of 68 cases (84%) of formalin-fixed, paraffin-embedded primary and/or metastatic carcinoma of the breast of various histologic types. The extent of S-100 immunoreactivity varied, with only a minor proportion of positive tumor cells noted in some cases. An awareness of this staining profile for S-100 protein, particularly in metastatic poorly differentiated neoplasms with unknown primaries, is imperative for accurate immunohistochemical interpretation. Using a panel of reagents which includes antibodies to keratin proteins and epithelial membrane antigen, the epithelial nature of S-100-positive carcinomas may be readily defined. Tumor cells in all cases of primary and metastatic carcinoma of the breast evaluated in this study exhibited strong staining for both of these tissue markers. To preclude misinterpretation of tumor type due to anomalous staining patterns for a specific antibody, eg, S-100 protein, a panel of antibodies is recommended for assessment of metastatic poorly differentiated tumors.

Intrathoracic granular cell tumour in a dog

Multiple granular cell tumours occurred diffusely throughout the pleura of an adult German Shepherd Dog. The growths were scattered over the surface of the lungs, mediastinum and diaphragm. Histologically, the masses consisted of plump cords of cells with eosinophilic, weakly PAS-positive cytoplasmic granules. Electron microscopically, the granules consisted of a pleomorphic population of electron-dense granules. The predilection site in the dog is the tongue and this is the first report of an intrathoracic, pleural site of granular cell tumours in the dog.

Granular cell tumours revisited. An immunohistological and ultrastructural study

Twenty-five granular cell tumours were stained with a panel of antibodies to histiocytic, muscle, neural, neural crest, epithelial and endothelial markers. Electron microscopy was also performed in six cases. Twenty-four of the cases were similar morphologically and immunocytochemically. One case with features of an endothelial origin is described. The present study strongly supports the viewpoint that granular cell tumours are a distinct entity rather than being the common appearance of a group of lesions of differing histogenesis. Origin from a neural crest-derived peripheral nerve-related cell is favoured.