Oral granular cell tumours: a histological and immunocytochemical study

Unusual presentation of granular cell tumour of buccal mucosa

Granular cell tumour (GCT) is a rare soft tissue lesion which many consider to have malignant potential of yet unknown aetiopathogenesis. Oral GCT lesions may occur in an area of leucoplakia and are predominantly present on the tongue. This case study highlights an uncommon presentation of this condition located on the buccal mucosa and illustrates the need for meticulous evaluation of suspicious lesions. Due to the malignant risk associated with GCT lesions, it is important to make the correct diagnosis and ensure complete surgical excision for these cases. Ongoing long-term follow-up is also indicated to monitor for recurrence or malignancy.

Paraganglioma of the Tongue in a Chow Chow Dog: A Comparison With the Human Counterpart and Literature Review

Over the last 20 years, substantial knowledge has been developed in Veterinary oncology, and tumors previously reported only in humans have been identified in animals. Primary paragangliomas of the tongue are extremely rare tumors in human beings and have never been reported in animals. A Chow Chow dog showed an ulcerated nodule at the lingual body, deeply infiltrated, which extended to the base of the tongue. A full clinical and pathological investigation was conducted, and a post-surgical follow-up of 6 months did not detect recurrence. Cytological, histological, and immunohistochemical features are presented and support the diagnosis of lingual paraganglioma. The paraganglioma of the tongue reported in this Chow Chow dog shares many similarities with the human counterpart.

Granular Cell Tumor of Cecum: A Common Tumor in a Rare Site with Diagnostic Challenge

Granular cell tumor (GCT) also known as Abrikossoff's tumor is a benign neoplasm that is usually seen in the fourth to sixth decades of life with slight female preponderance. It is most frequently seen in the oral cavity, skin, and subcutaneous tissue. Gastrointestinal tract involvement is uncommon, in which esophagus is the most commonly affected site. There are case reports of GCT in stomach, appendix, colon and rectum. In this article, we report a case of GCT involving cecum. The cell of origin in GCT is controversial. There are various pools of thoughts regarding its histogenesis, the details of which are reviewed in this article with emphasis on the diagnostic difficulties encountered in this tumor.

S-100 Negative Granular Cell Tumor of the Oral Cavity

Classic granular cell tumor is a mesenchymal neoplasm that commonly occurs on the skin, but is not infrequently found in the oral cavity, primarily on the dorsal tongue. Diagnosis is usually straightforward with hematoxylin and eosin stained slides. Immunohistochemical studies on classic granular cell tumor shows positive immunostaining for S-100 and vimentin, while CD68 is variably positive. We report a case of otherwise unremarkable oral granular cell tumor that was immunohistochemically negative for S-100, and positive for vimentin and CD68, and discuss the differential diagnosis. The results of the immunohistochemical studies in our case are compared with those of classic S-100 positive oral granular cell tumors, as well as cutaneous and oral S-100 negative granular cell tumors. Classic S-100 positive granular cell tumors and S-100 negative granular cell tumors of the oral cavity can only be distinguished by immunohistochemical studies; however, the necessity of this distinction is unclear, as both are benign lesions in which recurrence is unlikely.

Granular cell tumour in a patient with Crohn's disease treated with infliximab: coincidence or causal relationship?

Granular cell tumour (or Abrikossoff's tumour) was first described by Abrikossoff in 1926. This is a rare benign neoplasm of unclear histogenesis that is generally believed to be of nerve sheath origin. Usually, it presents as a solitary lesion, located mainly in the subcutaneous tissue of the head, or the neck, or in the oral cavity, such as a tongue lesion, although it may develop anywhere in the body. Approximately 1-2% of granular cell tumours are malignant. Granular cell tumours are extremely rare in patients with inflammatory bowel disease. To the best of our knowledge, granular cell tumours have never been reported in association either with Crohn's disease or scheduled infliximab treatment. Herein, we report a case of a granular cell tumour that presented as a subcutaneous skin nodule of the right lumbar area without any associated local or systemic symptoms in a 41-year-old woman with Crohn's disease who was receiving scheduled treatment with infliximab (5 mg/kg every 8 weeks) for 7 years.

Granular cell tumor of the cecum with extensive hyalinization and calcification: a case report

A granular cell tumor (GCT) is a benign neoplasm of unclear histogenesis that is generally believed to be of nerve sheath origin. GCT is not common and most often affects the tongue, skin and soft tissue, although it may occur anywhere in the body. We experienced a case of GCT that arose in the cecum of a 55-year-old man. The GCT was removed by laparoscopic resection. In addition to the tumor, endoscopic examination revealed the presence of a 5-mm-polyp in the descending colon and multiple tiny polyps in the sigmoid colon and rectum. Histological examination demonstrated a cecal tumor 1.5 cm x 1.0 cm x 0.7 cm with a hard consistency; in cut sections, mixed cells with yellowish and whitish portions were seen. The tumor was located between the mucosa and subserosa, and was composed of plump histiocyte-like tumor cells with abundant granular eosinophilic cytoplasm, which were immunoreactive for S-100 protein, vimentin, neuron-specific enolase, inhibin-alpha and calretinin. The tumor showed extensive hyalinization and focal dystrophic calcification. Immunohistochemical profiles did not confirm any particular cell type for the histogenetic origin of the GCT, including a nerve sheath origin. Extensive hyalinization and calcification showing involution of tumor cells suggest benign clinical behavior of GCT.

The unique simultaneous occurrence of a squamous cell carcinoma and a granular cell tumor of the tongue at the same site: a histological and immunohistochemical study

We report a case of a 47-year-old man with a granular cell tumor (GCT) of the tongue colocalized with a squamous cell carcinoma. To our knowledge, this is the first case to be reported in the literature with such an association. Furthermore, we performed an immunohistochemical analysis with p63 to distinguish pseudoepitheliomatous hyperplasia from invasive squamous cell carcinoma. Clinicians and pathologists must be made aware of this potential diagnostic pitfall so that the workup of a tongue lesion does not end prematurely with a benign diagnosis of granular cell tumor with overlying pseudoepitheliomatous hyperplasia.

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.

HMB-45 and Melan-A are Useful in the Differential Diagnosis Between Granular Cell Tumor and Malignant Melanoma

Granular cell tumors (GCTs), especially if atypical or malignant, may share cytomorphologic and architectural features with malignant melanoma, when the latter shows granular cell change. In many cases, these neoplasms can be differentiated from each other on histologic grounds, but distinction may sometimes be challenging. By immunohistochemistry, both tumors are strongly positive for S-100 protein and frequently express other nonspecific markers such as CD68, NSE, and NKIC3. In the current study, we reviewed 60 cases of conventional cutaneous, mucosal, and visceral GCT and studied the use of immunoperoxidase staining for the differential diagnosis between malignant melanoma and GCT. Immunohistochemical stains for S-100 protein, A, HMB-45, and microphthalmia transcription factor (MITF) were performed in all cases. All of the tumors were positive for S-100 protein. MITF immunostaining was diffusely positive in 53 (88%) cases, focally positive in three (5%) cases, and negative in four (7%). Fifty-seven (95%) tumors were negative for Melan-A, one case was focally positive, and two cases showed rare positive tumor cells. None of the tumors expressed HMB-45. In conclusion, GCT and malignant melanoma can be reliably differentiated on the basis of immunohistochemical stains in the majority of cases. Although not always positive in malignant melanoma, in this context, HMB-45 expression seems to be 100% specific for the diagnosis of melanoma. Melan-A is slightly less specific, with rare cases of GCT showing focal positivity. MITF is not useful in this differential-93% of the GCTs in our series showed nuclear reactivity for this marker. The latter finding highlights the limited specificity of this antibody in the diagnosis of melanocytic tumors.

Granular cell leiomyoma of the oral cavity

Granular cytoplasmic change is a reported but uncommon finding in leiomyoma. Leiomyoma in the oral cavity is also uncommon, and granular cell change in oral leiomyomas, to the best of our knowledge, has not been previously reported in the English literature. Two cases of oral leiomyomas with significant granular cell change are presented. These tumors may be confused with the more common granular cell tumor, however, routine histology and immunohistochemistry aided in establishing the diagnosis. Ultrastructural studies were done for one case. Both tumors were immunoreactive for muscle markers, namely, smooth muscle actin and desmin. One of the tumors (case 2) reacted postiviely for HHF-35 and alpha-1 antitrypsin. The tumors were unreactive for S-100 protein, pancytokeratin, myoglobin, and factor VIII related antigen (case 2).

Genetic profiling of granular cell myoblastoma

Granular cell tumor (GCT), or granular cell myoblastoma, is a relatively uncommon lesion of the soft tissues. It can occur in any organ, and the tongue is more often affected. GCT has unknown etiology, uncertain histogenesis, and a not always benign nature. Benign myoblastomas are the great majority, but rare malignant lesions have been reported. To have more information regarding the genetic events involved in GCT, the authors decided to perform an expression profile. A sample was derived from a surgically resected GCT of the tongue. RNA extracted from normal tongue (mucosa plus muscle) was used as control. By using DNA microarrays containing 19,200 genes, the authors identified several genes for which expression was significantly up- or down-regulated. The differentially expressed genes cover a broad range of functional activities: (1) signal transduction, (2) cell cycle regulation, and (3) cytoskeleton organization. It was also possible to detect some genes whose function is unknown. The data reported are, to the authors' knowledge, the first genetic portrait of GCT. Mutations in some of the described genes are related to neural alterations and mental diseases, and this fact supports the idea of a neural origin of myoblastoma. Several markers have been identified that will help in identifying the biological behavior (when malignant lesions will be described), as well as the gene whose products could be potentially disease-specific targets for therapy.

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.

Colocalized granular cell tumor and infiltrating ductal carcinoma of the breast

A 57-year-old woman presented with a 2-year history of a palpable mass in the upper inner quadrant of the right breast. A 1.1-cm, poorly circumscribed, firm tumor nodule was noted, consisting of 2 histologically distinct lesions in the same location, with some areas showing purely well-differentiated invasive ductal carcinoma and others composed of granular cell tumor. In 1 area, the 2 tumors collided and infiltrated each other. The invasive ductal carcinoma was admixed with ductal carcinoma in situ of solid and cribriform types. To our knowledge, this is the first case report demonstrating colocalization of these 2 neoplasms, which raises questions regarding causal relationship. We also review the literature on granular cell tumor of the breast.

S100A6 preferentially labels type C nevus cells and nevic corpuscles: additional support for Schwannian differentiation of intradermal nevi

BACKGROUND

Melanocytic nevi typically show a morphologic sequence of maturation from epithelioid "type A" cells to fusiform, Schwann cell-like "type C" cells with dermal descent. Nevi may also produce Wagner-Meissner-like structures (nevic corpuscles). Previous studies have shown that this maturation of intradermal nevi recapitulates intermediate stages in Schwann cell development. In intradermal nevi, we have evaluated the pattern of S100A6 protein, a form of S100 found in Schwann cells.

METHODS

Formalin-fixed, paraffin-embedded archival tissues were evaluated by immunohistochemistry using antibodies specific for S100A6 and S100B in 38 intradermal nevi (IDN). Ten neurofibromas (NF), 3 Schwannomas (SCH), 2 palisaded and encapsulated neuromas (PEN), and 2 granular cell tumors (GCT) were included as positive controls since these lesions have large numbers of Schwann cells.

RESULTS

Melanocytic nevi demonstrated preferential anti-S100A6 staining of "type C" cells (36/38; 28 strong, 8 weak) and nevic corpuscles (25/38; 19 strong, 6 weak) compared to "type A" cells (17/38; 17 weak) and "type B" cells (17/38; 4 strong, 13 weak). All NF, SCH, and PEN stained strongly with anti-S100A6. Both GCT were negative with anti-S100A6 but positive with anti-S100B.

CONCLUSIONS

The pattern of S100A6 expression in intradermal nevi further supports the hypothesis that maturation in these lesions recapitulates features of Schwann cell differentiation. The lack of S100A6 expression by both GCT suggests that these lesions have lost this feature of Schwann cells, which may play a role in their peculiar phenotypic appearance.

Immunohistochemical analysis of equine pulmonary granular cell tumours

Histopathological and immunohistochemical examinations were made on four female horses aged 9-12 years with pulmonary granular cell tumours (GCTs). The tumours, which were multiple, of varying size, firm and off-white in colour, surrounded the bronchi and bronchioles. Metastatic lesions were not detected. The tumour cells had abundant eosinophilic cytoplasm filled with prominent coarse eosinophilic granules. Immunohistochemically, these tumour cells reacted uniformly with vimentin and S100 antibodies. Most were immunolabelled by antibodies against glial fibrillary acidic protein (GFAP), myelin basic protein (MBP) and protein gene product 9.5 (PGP9.5), and a few cells were positive with Leu7 antibody. However, the tumour cells did not react with antibodies against neurofilament protein (NF), cytokeratin (CK), chromogranin, alpha1 antichymotrypsin (AACT), myoglobin, desmin, alpha-actin or alpha-smooth muscle actin (alpha-SMA). These immunohistochemical properties of tumour cells support the hypothesis that equine pulmonary GCTs are derived from Schwann cells of the peripheral nervous system in peribronchial and peribronchiolar tissues. GFAP, MBP, Leu7 and PGP9.5 antibodies should help to distinguish equine granular cell tumours from other tumours.

Bronchial granular cell tumor with osteopontin and osteonectin expression: a case report

The case of a 52-year-old Japanese man with bronchial granular cell tumors with osteopontin and osteonectin expression is reported here because there have been few investigations of their expression in benign tumors. He was admitted because of sudden hematemesis. A bronchoscopic examination revealed a lobulated polypoid tumor located in the left and right bronchi. Histologically, most tumor cells had abundant granular eosinophilic cytoplasm and were immunoreactive for S-100, neuron-specific enolase (NSE), CD68 and vimentin. Moreover, osteopontin-positive tumor cells were randomly distributed in the tumor tissue, but few stromal cells were positive. In contrast, osteonectin was mainly expressed in the peripheral tumor cells and was also distributed in the stromal cells. Blood vessels at the tumor border in which osteonectin-positive tumor cells were distributed, proliferated moderately. These results suggest that osteopontin and osteonectin may play a role in the progression of granular cell tumors and in the interaction between the tumor and host or angiogenesis around the tumor, respectively.

Malignant granular cell tumor metastatic to the orbit

OBJECTIVE

Malignant granular cell tumor is a rare type of soft tissue sarcoma. To our knowledge, ocular (eyelid) involvement has been described in only two cases. Herein, we report the clinicopathologic features of an unusual case of malignant granular cell tumor metastatic to the orbit.

DESIGN

Observational case report.

METHODS

Retrospective review of the medical record and the histopathologic and electron microscopic findings and review of the literature.

RESULTS

A 72-year-old man with biopsy-proven granular cell tumor in the cervical region was initially seen with proptosis and motility disturbance. A magnetic resonance imaging scan showed a large intraconal mass, and biopsy of the orbital mass revealed granular cell tumor. Histopathologic examination of the primary neck tumor and the orbital mass revealed increased nuclear atypia and pleomorphism in the consecutive lesions. The morphologic impression of granular cell tumor was also supported by the immunohistochemical demonstration of S-100 protein expression and ultrastructural findings typical of granular cell tumor. Six months after the orbital involvement, systemic workup revealed multiple apparent bony and lung metastases.

CONCLUSIONS

We report the first malignant granular cell tumor metastatic to the orbit and suggest the inclusion of this tumor in the differential diagnosis of metastatic orbital lesions.