Granular cell variant of neurofibromatosis: ultrastructure of benign and malignant tumors

Histopathological Variants of Cutaneous Neurofibroma: A Compendious Review

The first description of histopathological variants of neurofibroma dates back to 1994. Over the years, many individual case reports elucidating unusual histologic features in neurofibroma have been added to the literature, some of which have defined criteria, with the others falling under the roof of benign neural neoplasms. These unusual features, which sometimes may lead to pauses in identifying a common benign tumor such as neurofibroma. Awareness of these variants may help dermatopathologists avoid misinterpretation. Thus, this review aims to summarize all novel and unusual histopathological variants of cutaneous neurofibroma reported to date, in addition to any unusual variants that we encountered in our practice.

Malignant granular cell tumor of the median nerve: a case report with a literature review of 157 cases

Malignant granular cell tumors are an extremely rare, high-grade sarcoma with a schwannian phenotype and are composed of malignant granular cells with cytoplasmic lysosomal inclusion. To date, 157 cases of malignant granular cell tumors have been reported. We report the first case of a malignant granular cell tumor arising from the digital nerve to the median nerve in the palm, and we review the 157 previously reported cases and summarize the clinical profile, treatment, and outcome of this tumor. The median age, tumor size, and follow-up periods were 51 years, 6 cm, and 24 months respectively. With respect to the oncological result, 53 patients (33.8%) had no evidence for disease, 31 (19.7%) were alive with the disease, and 51 (32.5%) died because of the disease. Our case report indicates that rare malignant tumors can arise from the digital nerve to the median nerve in the palm, an anatomical site that is usually affected by benign lesions. Exhaustive discussions between surgeons and pathologists are necessary for the treatment of this rare malignant tumor.

Granular cell tumor of brachial plexus mimicking nerve sheath tumor: a case report

Primary tumors of the brachial plexus region are rare and granular cell tumors arising from the brachial plexus region is an extremely rare disease. We present a case of granular cell tumor arising from of the brachial plexus which appeared to be a usual presentation of nerve sheath tumor before the pathological confirmation. We report a granular cell tumor of the brachial plexus with literature review. Total resection is important for good clinical outcome and prognosis in the treatment of granular cell tumor.

Brachial plexus tumors in a consecutive series of twenty one patients

Objective

This is a retrospective review of 22 surgically treated benign and malignant tumors of brachial plexus region to describe clinical presentation, the characteristics of brachial plexus tumor and clinical outcomes with a literature review.

Methods

Twenty-one patients with consecutive 22 surgeries for primary brachial plexus tumors were enrolled between February 2002 and November 2011 were included in this study. The medical records of all patients were reviewed.

Results

Eleven male and 10 female patients were enrolled. Mean age was 39 years. Three patients had brachial plexus tumor associated with neurofibromatosis (13.6%). Presenting signs and symptoms included parenthesis and numbness (54.5%), radiating pain (22.7%), direct tenderness and pain (27.2%), palpable mass (77.3%). Twelve patients presented preoperative sensory deficit (54.5%) and 9 patients presented preoperative motor deficit (40.9%). Twenty tumors (90.9%) were benign and 2 tumors (9.1%) were malignant. Benign tumors included 15 schwannomas (68.2%), 4 neurofibromas (18.2%) and 1 granular cell tumor (4.5%). There were 1 malignant peripheral nerve sheath tumor (MPNST) and 1 malignant granular cell tumor. Gross total resection was achieved in 16 patients (72.7%), including all schwannomas, 1 neurofibroma. Subtotal resection was performed in 6 tumors (27.3%), including 3 neurofibromatosis associated with brachial plexus neurofibromas, 1 MPNST and 2 granular cell tumor in one patient.

Conclusion

Resection of tumor is the choice of tumor in the most of benign and malignant brachial plexus tumors. Postoperative outcomes are related to grade of resection at surgery and pathological features of tumor.

Peripheral nerve sheath tumors of the gastrointestinal tract: a multicenter study of 58 patients including NF1-associated gastric schwannoma and unusual morphologic variants

The frequency and morphological spectrum of gastrointestinal peripheral nerve sheath tumors (PNSTs) from consecutive case material has not been studied in the c-KIT era. We reviewed all mesenchymal gastrointestinal (GI) lesions at our departments according to current diagnostic criteria. PNSTs formed the third commonest group of mesenchymal GI tumors with a lower frequency (< or =5%) compared to gastrointestinal stromal tumors (GISTs; approximately 50%) and smooth muscle neoplasms ( approximately 30%). Granular cell tumors (GCTs; n = 31) and schwannomas (n = 22) were the most common types of PNSTs encountered. Rare tumors included neurofibromatosis 1 (NF1)-associated PNSTs (n = 5) and gastric perineurioma (n = 1). Thirteen schwannomas (including also some recent cases) were initially diagnosed as GIST, leiomyoma, or neurofibroma. Unusual histological variants included sigmoid GCT with prominent lipomatous component (n = 1), reticular-microcystic schwannoma of small (n = 1) and large (n = 1) bowel, NF1-associated gastric schwannoma (the first case to date), and psammomatous melanotic colonic schwannoma unrelated to Carney complex (n = 1). PNSTs coexisted with GIST in four patients (three had definite NF1). In conclusion, PNSTs of the GI tract are rare uniformly benign neoplasms that may show schwannian, perineurial, fibroblastic, or mixed differentiation. Most of them (92%) occurred sporadically unassociated with NF1 or NF2. Gastrointestinal PNSTs are still underrecognized by general pathologists. Awareness of their diverse morphology will help to avoid confusing them with smooth muscle neoplasms and GIST that they may closely mimic.

Granular cell tumor arising metachronously in the bronchus and esophagus

We present a case of granular cell tumor (GCT) occurring in the esophagus 7 years after operation for bronchial GCT. A 59-year-old Japanese man complained of epigastralgia, and endoscopic examination of the upper digestive tract disclosed a submucosal tumor in the lower esophagus. Histological examination of the endoscopic mucosal resection of the esophageal tumor showed a proliferation of neoplastic cells with an eosinophilic and granular cytoplasm. The cytoplasm of the neoplastic cells was histochemically positive for PAS stain and immunohistochemically positive for S-100. This tumor did not fulfill any of the diagnostic criteria for malignancy at either the macroscopic or microscopic level. I believe that this is the first case of GCT occurring metachronously in the respiratory and digestive tracts. Clinicians and pathologists should bear in mind that GCT may arise metachronously in the respiratory and digestive tracts.

Multiple cutaneous granular cell tumors, joint hypermobility and mild facial dysmorphism in a child

BACKGROUND

The association of multiple cutaneous granular tumors with systemic defects is extremely rare. To date, 14 cases have been described.

CASE REPORT

A 14-year-old boy presented multiple nodular lesions on his arms and legs; facial dysmorphism and joint hypermobility were also present. Histopathologic examination of two nodules showed granular cell tumors. We review the literature regarding multiple granular cell cutaneous tumors in children with associated somatic defects and genetic syndromes.

CONCLUSIONS

The combination of multiple cutaneous granular tumors with alterations in other organs is not only fortuitous, justifying the proposal of a distinct syndrome, termed "Bakos's syndrome" after the author who first described this association. The relation with neurofibromatosis type 1 is discussed, and an association is suggested with the range of variants of this syndrome.

Well-differentiated chondrosarcoma of the humerus with prominent granular cell component: a hitherto unreported occurrence

We report the case of a well-differentiated chondrosarcoma of the proximal humerus in a 60-year-old man that featured a prominent component of granular cells, the granules being shown by electron microscopy to be lysosomal. Although secondary granular cell changes have been described in a large variety of tumor types, this is, to the best of our knowledge, the first documentation of this phenomenon in a skeletal chondrosarcoma.

Multiple cutaneous granular cell tumors in a child with possible neurofibromatosis

A 4-year-old girl with possible neurofibromatosis I had multiple subcutaneous nodules. On histopathologic examination, these nodules were diagnosed as multiple cutaneous granular cell tumors. An association between these tumors and neurofibromatosis I has been suggested because of their common neuroectodermal origin. We review cases of multiple cutaneous granular cell tumors in association with neurofibromatosis I in childhood.

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.

Malignant granular cell tumour of the sciatic nerve

A case of malignant granular cell tumour of the sciatic nerve is presented. Computed tomography demonstrated isodensity with muscle and minimal enhancement. Magnetic resonance demonstrated T1 isointensity with muscle with marked enhancement, and isointensity with fat on proton and T2 images. Pathological evidence is presented for its probable Schwann cell histogenesis.

Multiple cutaneous granular cell tumors with systemic defects: a distinct entity?

BACKGROUND

The association between cutaneous granular cell tumors and systemic defects is extremely rare, this being the tenth case reported in the literature. The reported defects in the literature include lentiginosis, face and skull alterations, heart defects, muscular and neural pathologies, among other sporadic defects in other organs. The patients do not present visceral granular cell tumors.

CASE REPORT

An 11-year-old girl had 124 skin granular cell tumors associated with face and skull defects, pulmonary stenosis, EEG and other neurologic alterations, diffuse muscle hypotonia, and an excess of finger joint mobility.

CONCLUSIONS

The combination of multiple cutaneous granular cell tumors with repeated alterations in other organs seems to be more than simply coincidental, thus suggesting a syndromic separate entity.

Intraocular and orbital malignant schwannomas in F344 rats

Intraocular and orbital malignant Schwannomas in two F344 rats are presented. The two Schwannomas were identified among approximately 60,000 male and 60,000 female F344 rats. The intraocular malignant Schwannoma occurred in the iris, invading the corneal stroma through the destroyed Descemet membrane. The malignant orbital Schwannoma occurred in the left orbit, invading the contralateral orbit along the optic nerve. Histologically, the intraocular Schwannoma consisted predominantly of a perivascular fascicular pattern of plump spindle cells associated with marked cytoplasmic vacuolization. The orbital Schwannoma consisted of Antoni type A and B pattern, but Antoni B tissues predominated. Antoni A tissues consisted of closely packed, elongated spindle cells arranged in interlacing fascicles, while Antoni B tissues were highly cellular and consisted of anaplastic, small cells associated with marked cyst formation. Immunohistochemically, the intraocular Schwannoma had a positive immunoreactivity for S-100 protein, while the orbital Schwannoma had a negative immunoreactivity. Ultrastructurally, the cells of both intraocular and orbital Schwannomas had long, thin cell processes and pericytoplasmic basal laminae. Particularly, the plump spindle cells of the intraocular Schwannoma were most strikingly characterized by the well developed, extremely attenuated cell processes arranged in a lamellar or spiral pattern. These cell processes and cell bodies were associated with numerous desmosomes. Intracytoplasmic filamentous granules and bodies, consisting of intermediate filaments approximately 7 nm in width, were additional characteristics of the plump spindle cells.

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.

Malignant granular cell tumor: immunocytochemical and ultrastructural observations

Malignant granular cell tumor is an exceedingly rare tumor and only a few cases are documented in the literature. We report a malignant granular cell tumor of the subcutaneous tissue of the thigh in a 59-year-old man, and discuss the ultrastructural and immunocytochemical findings and their diagnostic value.

Granular cell basal cell carcinoma

Granular cell basal cell carcinoma (BCC) is a rare histologic variant of BCC. In this, the third reported case, the tumor consisted almost entirely of granular cells. By electron microscopy, these cells were filled with pleomorphic lysosome-like granules lined by unit membranes and containing homogeneous or granular electron-dense bodies, membranous debris and amorphous material. The epithelial origin of the tumor was suggested by the characteristic light microscopic appearance of tumor cell islands with some areas of peripheral palisading, and was confirmed by electron microscopic features of numerous well-formed pentalaminate desmosome junctions and sparse cytoplasmic tonofilament bundles, some of which showed attachments to the desmosomes. Histochemical immunoperoxidase stains for lysozyme showed no cytoplasmic lysozyme activity, in common with other granular cell tumors, but ultrastructural examination did not reveal angulate bodies, in contrast to findings in non-epithelial granular cell tumors.

Granular cell myoma and schwannoma: fine structural and immunohistochemical study

We present the histological, ultrastructural, and immunohistochemical findings of two granular cell tumors of different histogenesis: a mediastinal granular cell schwannoma, and an uterine granular cell leiomyoma. Ultrastructurally the mediastinal tumor showed granular cell changes of the Schwann cells which were reactive for S-100 protein and Leu 7 antigen, but not for actin, desmin, CEA, EMA, or cytokeratin. Ultrastructural study of the uterine lesion demonstrated smooth muscle cells with only a few "autophagic" facuoles to cells nearly replaced by lysosomes. Immunohistochemically this tumor showed reactivity for actin, desmin, and Leu 7 antigen, but was S-100 protein, CEA, EMA, and cytokeratin negative.

Granular cell angiosarcoma of the skin: histology, electron microscopy and immunohistochemistry of a newly recognized tumor

We report a unique angiosarcoma of the skin of the face in which a large part of the tumour was of granular cell appearance. Histologically the granular cells resembled those of conventional granular cell tumours. By electron microscopy the granules were identical to those of granular cell tumours but other features were lacking. Stains for vimentin and factor VIII related antigen were positive, but for S-100 protein and CEA were negative. The occurrence of granular cell change in an angiosarcoma supports the view that granular cell tumours are histogenetically diverse.

Granular cell tumor arising in myelinated peripheral nerves. Light and electron microscopy and immunoperoxidase study

The histologic, immunohistochemical and ultrastructural characteristics of two granular cell tumors arising from the right recurrent laryngeal and left facial nerves are described. S-100 protein was detected both in the nuclei and cytoplasm of the granular cells using the peroxidase-anti-peroxidase method. The ultrastructural findings in both cases support a Schwann cell derivation of the granular cells. It is suggested that the granularity of cells of granular cell tumor may represent a lysosomal disorder affecting most frequently neoplastic and nonneoplastic Schwann cells and occasionally other cells.