Symptomatic Granular Cell Tumor Involving the Pituitary Gland in a Dog: A Case Report and Review of the Literature

A granular cell tumor involving the pituitary gland, optic chiasm and ventral pyriform lobes was discovered in a 12-year-old Labrador Retriever. Clinical signs included acute blindness, seizures, ataxia, weakness, and behavioral changes. The diagnosis was established by histopathologic and ultrastructural examination of neoplastic tissues collected at necropsy. Granular cell tumors involving the central nervous system are well documented in humans but rarely have been described in dogs. The location of the neoplasm and the clinical symptoms seen in this dog closely parallel those of a rare syndrome in humans commonly described as symptomatic parasellar or pituitary granular cell tumors. The cell of origin for these tumors is still highly debated, and attempts to characterize human granular cell tumors through immunohistochemistry have produced conflicting results. An immunohistochemical profile of this neoplasm revealed focal positive staining for vimentin with a lack of staining for neuron-specific enolase, glial fibrillary acidic protein, S-100, and synaptophysin. All neoplastic cells were strongly positive with the periodic acid-Schiff reaction.

Granular cell tumor of the breast

Granular cell tumor is a rare benign soft-tissue neoplasm, usually appearing in the tongue, the oral cavity and subcutaneous tissue. Examples of granular cell tumor of breast are encountered in 30-50-year-old women. Herein, we report ultrasonographic and mammographic imaging findings of a 59 years old woman presented with a painless palpable mass, which was diagnosed as granular cell tumor on histopathological analysis.

Granular cell astrocytoma. A case report with immunohistochemical and ultrastructural characterization

Granular cell astrocytoma (GCA) is an uncommon type of granular cell tumours (GCTs) in the central nervous system. Granular cells in these tumours are of enigmatic origin. We report a case of cerebral GCA in a 59-year-old man who suffered from diabetes and Addison-Biermer disease. The tumour was localized in the left parietal lobe. Microscopically, the tumour was almost entirely composed of large, polygonal cells with round to oval, granular eosinophilic, PAS-positive cytoplasm. The nuclei were located centrally or eccentrically and sometimes exhibited nucleolar vacuoles. The tumour cells were arranged in nests surrounded by blood vessels and connective tissue. Immunohistochemically, the granular tumour cells were reactive for GFAP and vimentin. They were intensively stained for ubiquitin and some of them were reactive for CD68. Moreover, a lot of stromal cells expressed CD68 reactivity. Ultrastructurally, most tumour cells were round or oval with only a few or without filaments. Their cytoplasm was filled with electron-dense granular material limited by a single membrane and autophagic vacuoles. Another type of tumour cells, present in a significantly lower number, revealed abundant cytoplasm with numerous intermediate filaments, swollen rough endoplasmic reticulum, mitochondria and a few clusters of granular material. Cells with numerous condensed electron-dense, bizarrely-shaped mitochondria and few filaments were occasionally observed. Among granular cells, macrophages with vacuoles and/or lamellar structures were visible. In our case, both immunohistochemical and ultrastructural analysis supported astroglial origin of the granular cell tumour.

Morphometry of pseudoepitheliomatous hyperplasia: objective comparison to normal and dysplastic oral mucosae

OBJECTIVE

To compare the architectural and morphometric features of pseudoepitheliomatous hyperplasia (PEH) associated with oral granular cell tumors (GCT), normal oral mucosa and oral epithelial dysplasia.

STUDY DESIGN

Quantitative comparisons between the diagnostic entities were carried out at the tissue level by estimating the fractal complexity of the epithelial connective tissue interface and at the cellular level by analyzing the morphometric features of algorithmically segmented epithelial cell areas.

RESULTS

Casewise multivariate analysis showed that the fractal properties produced a correct discrimination rate of 96.4% between PEH and normal mucosa. Cellular parameters gave a 100% correct discrimination rate between PEH and mild dysplasia. Combining the fractal and cellular properties also showed 100% discrimination between PEH and normal mucosa and between PEH and mild dysplasia.

CONCLUSION

The results show that PEH associated with GCT displays quantifiable morphometric features that make it differentiable from normal oral mucosa and oral epithelial dysplasia.

Granular cell tumor of the parotid gland. A case report

BACKGROUND

Granular cell tumor (GCT) is a relatively uncommon soft tissue tumor of putative Schwann cell origin. This tumor can occur in multiple sites as a small, nontender nodule, but the parotid gland is unusual, and only several cases have been reported.

CASE

A 46-year-old woman presented with a slowly growing mass in the left preauricular region for three years. Imaging studies confirmed a nodular lesion in the superficial lobe of the left parotid gland. Fine needle aspiration (FNA) cytology revealed scattered cellular clusters and single cells with abundant granular cytoplasm and indistinct cell borders. Background exhibited eosinophilic, granular, cytoplasmic material, and some scattered naked nuclei were also noted. Histologic examination with supportive immunohistochemical and ultrastructural studies confirmed GCT.

CONCLUSION

GCT of the parotid gland is very unusual. Recognition of this tumor is important to make a definitive diagnosis before an operation. FNA is useful procedure in GCT of parotid gland for a preoperative diagnosis and proper treatment.

S-100-negative atypical granular cell tumor: report of a case

A 38-year-old man presented with a solitary, round, 1.2 x 1.2 cm, bluish-colored, dome-shaped, hard nodule on the left side of the neck, which had grown over 2 months (Fig. 1). The nodule was nontender and nonmovable. Light microscopy revealed that the neoplasm was situated in the reticular dermis with extension into the papillary dermis. The tumor showed expansile growth with smooth and round borders, and was made up of sheets of cells arranged in nests or lobules separated by thin delicate connective tissue septa. The tumor cells were round, oval, or polygonal in shape with distinct cellular borders. The cells had abundant eosinophilic granular cytoplasm, and considerable variation of cellular and nuclear size was noted (Fig. 2a). The tumor cell nuclei were vesicular and some had pleomorphism (Fig. 2b). Sometimes multiple nucleoli were seen. Mitoses and necrosis were virtually absent. Immunohistochemical staining revealed that some of the cytoplasmic granules stained positively with periodic acid-Schiff (PAS) after diastase treatment. Tumor cells showed strong reactivity for CD68 and neuron-specific enolase, and negative results for S-100, factor XIIIa, cytokeratin, desmin, CD34, and smooth muscle actin. Electron microscopy revealed that the tumor was composed of polygonal cells with round to irregular nuclei, and the cytoplasm contained numerous secondary lysosomes. The tumor was completely excised.

Granular cell tumor of the canine central nervous system: two cases

Although pure granular cell tumors have been reported in various sites in the dog, only one tumor has been reported in the central nervous system. Two dogs presented with neurologic signs had brain lesions detected by magnetic resonance imaging in the area of the olfactory bulbs and frontal cortex. In both dogs, a clinical diagnosis of a granular cell tumor was made from tissues obtained from stereotactic biopsies guided by computed tomography. Surgical removal of the tumors was followed by histopathologic, ultrastructural, and immunocytochemical characterization. Although not conclusive, these studies indicated that the granular cells were not of leucocyte origin but may have been derived from the meninges. One dog died 12 months after surgery, and the other was alive 4 months later.

Nine cases of granular cell tumors in B6C3F1 mice

The histological characteristics of 9 cases of granular cell tumors (GCTs) observed in B6C3F1 mice were examined to determine their cellular origin. Seven of the 9 cases were found in the uterus and other 2 cases were in the subcutaneous tissue. Tumor cells had abundant granules in the cytoplasm which were stained with PAS and were resistant to diastase treatment. Ultrastructurally, the granules were identified as lysosomes. The cell surface had cytoplasmic processus showing interdigitation with adjacent cells. A character feature of the tumor cells was the presence of a desmosome-like structure on their cell surface but no basal lamina was demonstrated. Although GCTs have been considered to be derived from Schwann cells on the basis of their ultrastructural features and S-100 protein-immunopositive findings, the absence of basal lamina in the present cases may raise a controversy as to their origin.

Granular cell tumor: a review and update

The histogenesis of granular cell tumor (GCT) has been a source of controversy since its recognition as an entity by Abrikossoff in 1926. These lesions can occur in virtually any location. Benign GCTs are not uncommon, but malignant ones are rare and at times difficult to diagnose. The main morphologic feature is the granularity of the cytoplasm which is caused by a massive accumulation of lysosomes. Early suggestions that GCT may have a myoblastic origin have been discounted and use of the term granular cell myoblastoma as a designation for this tumor is discouraged. Although most investigators currently favor a Schwann cell derivation based on immunohistochemical and electron microscopic findings and advocate the designation of granular cell schwannoma, some differences exist between schwannomas and GCTs in their ultrastructural characteristics and the expression of some immunohistochemical markers. Other investigators believe that GCT is not a specific entity but rather a degenerative change that can occur not only in Schwann cells but also in a variety of other normal and neoplastic cells. Until more information becomes available, particularly that derived from cytogenetic studies, this lesion should be considered a separate entity and the descriptive designation of granular cell tumor continues to be appropriate.

Granular cell tumor: a review of the pathology and histogenesis

As the name suggests, the histogenesis of the granular cell tumor is uncertain, but this intriguing neoplasm has occasioned much speculation and controversy since its description in 1926 as a myoblastoma. Though ubiquitous in its anatomic location, it is usually small, solitary, benign, and readily recognized by routine light microscopy, and questions concerning it are principally academic. However, a small number of cases are malignant and they can be difficult to identify in paraffin sections. The combined input from immunohistochemistry and electron microscopy has greatly clarified understanding of the morphology of this lesion and both methods are helpful when the differential diagnosis is a problem. The cell of origin is still undecided, and although distinct neural features argue for Schwannian origin, the noncommittal term granular cell tumor continues to be appropriate.

Congenital CD34-positive granular cell dendrocytosis

Granular cell tumors involving the skin are mostly acquired lesions. The Schwann cell origin of these lesions is supported by positive immunostaining for S-100 protein and myelin basic protein. S-100- granular cell lesions rarely have been described in association with fibrous papules or dermatofibromas. The congenital variety of S-100- granular cell tumors occurs almost exclusively in the gingiva. The cell origin of these lesions is not well delineated. We report a hitherto undescribed case of a congenital cutaneous lesion which is histologically characterized by diffuse dermal infiltrates of S-100- but CD34+ granular dermal dendrocytes. The granular appearance of these CD34+ dendrocytes is attributed to an abundance of phagolysosomes. The pathogenetic mechanism of this unusual lesion remains to be elucidated.

[Endobronchial granular cell tumor. A report of two cases in the course of staging of ORL cancers]

We report two new observations of endobronchial granular cell tumor discovering by bronchoscopy, during the staging of head and neck cancers. This site remains exceptional; the histologic features are well known. The ultrastructural and especially the immunohistological criteria trend to indicate a neurogenic histogenesis. Although the course is benign in this site and no malignant forms have been reported, local relapses are possible. However, some benign cases may have disturbing endoscopic and histologic features.

Morphological and ultrastructural study of the histogenesis of meningeal granular cell tumors in rats

To clarify the cell of origin of granular cell tumors in the rat brain, light and/or electron microscopic examinations were performed on 40 cases of spontaneous meningeal tumors in Wistar (Jcl: Wistar) rats. The meningeal tumors were histologically subclassified into 3 types: meningothelial meningiomas (MMs), 3 cases; granular cell tumors (GCTs), 28 cases; and mixed forms (MIXs) of GCTs and MMs, 9 cases. Of these tumors, 2 MMs, 2 GCTs, and 3 MIXs were examined by transmission electron microscopy. Tumor cells of MMs were characterized by cytoplasmic intermediate filaments and prominent interdigitating cell processes often connected with cellular junctions without surrounding basal laminae. GCTs were composed of 2 cell types: granular cells with many dense bodies and filamentous cells with fine intermediate filaments. MIXs consisted of granular cells, filamentous cells, and intermediate cells. The tumor cells in GCTs and MIXs were apposed to each other and connected with cellular junctions. MIXs displayed a spectrum of cellular differentiation in that 2 MIXs had a close morphological resemblance to GCTs and the other one to MMs. These findings indicate there might be a histogenetic sequence among MMs, GCTs, and MIXs. The present study supports the suggestion that GCTs and MIXs may be variants of MMs from the meningeal arachnoid cell.

[Granular cell tumor of the larynx]

Granular cell tumor is an unusual growth of probably neuroectodermal histogenesis, first reported by Abrikossoff in 1926 with the name of myoblastoma. Of the about 1200 cases reported since, the 50 percent were found in the head and neck. Of second mentioned 10 percent had a laryngeal sitting. A case of glottic granular cell tumor surgically removed with free borders is presented. Bibliographical review.

Fine-needle aspirates of granular cell lesions of the breast: report of three cases, with emphasis on differential diagnosis and utility of immunostaining for CD68 (KP1)

Fine-needle aspiration biopsy (FNA) has been recognized as a safe and reliable procedure for evaluating breast lesions. We herein report cytologic findings for needle aspirates from three granular cell nodules of the breast. The nodules were detected by diagnostic imaging and ranged from 0.6 to 1 cm in diameter. Ultrasound-guided FNA was used in all cases and revealed cellular aspirates with similar cytomorphologic features consisting of sheets of large granular cells intersected by arborizing thin-walled blood vessels. The cells had round to oval nuclei, inconspicuous nucleoli, and abundant, often ill-defined granular cytoplasm. Tissue sections of resected specimens yielded final diagnoses of granular cell metaplasia of histiocytes and stromal cells in one case and granular cell tumor (GCT) in the other two cases. FNA smears in all three cases were strongly positive for the lysosomal marker CD68 (KP1) and S-100 protein; therefore, it was not possible to distinguish true GCT from granular cell metaplasia/granular histiocytes. When breast aspirates reveal granular cell changes, excisional biopsy should be done for a definitive diagnosis.

Suprasellar granular cell tumor

A 75-year-old female presented with a suprasellar granular cell tumor. Computed tomography (CT) revealed a high dense suprasellar mass with strong postcontrast enhancement. Magnetic resonance imaging showed a round suprasellar mass, which was hyperintense on the T1-weighted images with nonhomogeneous enhancement after the administration of gadolinium-diethylenetriaminepenta- acetic acid, and hypointense on the T2-weighted images. Cerebral angiography demonstrated no abnormal findings. The tumor was partially removed via a right frontotemporal craniotomy. The histological diagnosis was suprasellar granular cell tumor. Her postoperative course was uneventful other than mild and transient diabetes insipidus. She has remained asymptomatic without CT evidence of tumor regrowth for 20 months after the surgery. Immunohistochemical studies showed positive reaction for S-100 protein in the tumor cell nuclei, but no reaction for glial fibrillary acidic protein, neurofilament protein, Leu-7, oxytocin, beta-endorphin, adrenocorticotropic hormone, and vimentin. This case provides additional evidence for the astrocytic origin of suprasellar granular cell tumor.

An unusual round cell tumor of the tibia with granular cells

We present the clinical, radiographic and histopathologic findings of an unusual tumor that originated in the diaphysis of the tibia in a 10-year-old boy. Clinical symptoms had been present for approximately 2 years and radiographic abnormalities for > or = 8 months before biopsy and subsequent resection of the neoplasm. The child is doing well 4 1/2 years later. Microscopically, the tumor was not typical of any bone tumor with which we are familiar. It was a round-cell tumor with extensive fibrosis, prominent cytoplasmic granularity, and isolated immunoreactivity for vimentin, epithelial membrane antigen, and antichymotrypsin. Ultrastructural examination uncovered the presence of both well-formed desmosomes and cell-associated basement membrane material in addition to abundant phagolysosomes. Classification of this tumor is a challenge; the differential diagnosis includes atypical adamantinoma, atypical Ewing's sarcoma, and small-cell osteosarcoma. We favor the former interpretation, although we raise the possibility that it may be a unique lesion.

Granular cell tumor of the pituitary stalk. Case report

The case is described of a granular cell tumor of the pituitary stalk in a 40-year-old woman with secondary amenorrhea. A computerized tomography scan showed a large contrast-enhancing mass, and T1-weighted magnetic resonance images demonstrated a tumor isointense to the brain parenchyma with nonhomogeneous enhancement after intravenous administration of gadolinium diethylenetriamine penta-acetic acid. Histopathological examination, especially immunocytochemical and electron microscopic studies, showed elements supporting an astrocytic origin for this type of tumor, a hypothesis advanced by many authors but still controversial.

Malignant granular cell tumor

We report a case of malignant granular cell tumor present in the left medial mid-thigh of a 69-year-old black male. The lesion was grossly fungating, partially ulcerated and measured 14 cm in largest diameter. Light microscopy, electron microscopy and immunohistochemistry techniques were used to confirm the preliminary cytologic diagnosis of malignant granular cell tumor. Diagnostic criteria of malignancy for such lesions are reviewed. Immunohistochemical and ultrastructural analyses support a neural or Schwann cell origin for the tumor. Clinical outcome for such lesions is discussed.

Relationship of clear cell oncocytoma to mitochondrial-rich (typical) oncocytomas of parotid salivary gland. An ultrastructural study

Nosologically, the designation clear cell oncocytoma seems illogical and contradictory when the definition of an oncocytoma relies on mitochondrial-rich cells; its relationship to the granular (mitochondrial-rich) oncocytoma needs further clarification. Electron microscopy of six examples of oncocytoma from five patients allowed assessment of cellular features in three clear cell variants, two typical oncocytomas and one with a roughly equal proportion of clear and granular tumor cells. Ultrastructurally, in the clear cell types of oncocytoma, a considerable to extensive portion of the central cytoplasm was occupied by monoparticulate glycogen with margination of mitochondria and other organelles. The degree of extraction of the glycogen during fixation and processing accounts for variation in the extent of the clear cell component as phosphotungstic acid-hematoxylin staining reveals considerable mitochondria in many of the tumor cells in the clear cell variant of oncocytoma. Ultrastructural findings further support an interrelationship between clear and granular cells, as some typical oncocytes are evident in the clear cell variant of oncocytoma, and one oncocytoma in this series had a roughly equal number of glycogen-rich and mitochondrial-rich tumor cells both of which took part in the formation of microlumens. The designation clear cell oncocytoma is appropriate within the oncocytoma subgroup of salivary gland tumors.

Granular cell tumors

The skin and subcutaneous tissue and mucosae of the head and neck are areas of predilection for granular cell tumors. These often histogenetically enigmatic lesions have two principal clinicopathologic presentations: an infantile (congenital) epulis form of the gnathic gingiva and a noncongenital soft tissue and aerodigestive form. Recurrences of either form are largely attributable to marginal excision and, for all sites, approach 15%. A malignant granular cell tumor is recognized, but requires rigorous histologic confirmation.

[Granular cell (Abrikosov) tumors treated with CO2 laser]

In five cases Abrikosoff-tumors were recognized and examined by electron microscope and immunohistochemical methods. The site of origin was at three patients the larynx and at 2 patients the tongue. The authors are dealing with the CO2-laser as a new treatment possibility of granular cell tumors. Since years they have not seen recurrences. Because of the painless postoperative period, the quick recovery and good functional results CO2-laser surgery seems to be the treatment of choice in these cases.

[Neurofilaments in Abrikosov's tumor (an immunohistochemical study)]

Abrikosov's tumour was studied light- and electron-microscopically and immunohistochemically with the use of antibodies against desmin, myoglobin, vimentin, cytokeratin, glial fibrillar acid protein, neuron-specific enolase, S-100 protein, neurofilaments (68 kd), lysozyme, alpha-1-antichymotrypsin, alpha-1-antitrypsin, structural components of extracellular matrix (collagen I, II, III, IV, V types and fibronectin). The presence of neurofilaments, apart from vimentin, S-100 protein and small amount of neurospecific enolase, in the tumour cells is demonstrated for the first time. Neurofilament expression by tumour cells and the lack of the basal membrane collagen (type IV) in the extracellular matrix indicate the cell differentiation different from that of Schwann cells. A similar cell immunophenotype is typical for tumours of sympathetic ganglion and paraganglion structures. Both these results and literature data prove phenotypic heterogeneity of the granular cell tumours and their histogenetic link with the cells of nervous comb.

Granulated round cell tumor of cats

Morphologic and biologic features of five feline granulated round cell tumours were compared with those previously reported to be of globule leukocyte and large granular lymphocyte origin. The five cats ranged from 6 to 9 years of age and presented with nonspecific gastrointestinal signs. Four of the five cats were tested for feline leukemia virus and were negative by enzyme-linked immunosorbent assay. The neoplastic process involved the abdominal cavity in all cases, with a predilection for the distal small intestine and mesentery. The liver and peripheral and thoracic lymphoid tissues were also sporadically affected. Neoplastic round cells contained 0.5-1.5-microns eosinophilic cytoplasmic granules that were difficult to discern on causal observation with hematoxylin and eosin stain but were deep blue and easily visualized when stained with phosphotungstic acid-hematoxylin. In two cases, epithelium in the affected ileum and liver contained unusually large numbers of apparently normal globule leukocytes. Ultrastructurally, the tumor granules tended to cluster at one nuclear pole and were spindle to round in shape with variably dense contents. Some granules contained a dense "cap" at one end or internal crystalloid bars that distorted the granule membrane. The tumors reported herein are similar to all three of the previously reported feline granulated round cell tumors and probably have a common cellular origin.

A granular cell tumor of the buccal mucosa--a case report

In the oral region, granular cell tumors often occur in the tongue, but rarely in the buccal mucosa. A case of granular cell tumor in the right buccal mucosa of a 74 year-old female is described. An elastic-hard solid mass about 1 cm in diameter was palpated under the right buccal mucosa. It was well-defined from the proximal tissues and adhered to part of the buccal mucosa. As a result of a biopsy, the diagnosis of a granular cell tumor was made. The tumor was resected together with the surrounding tissues under local anesthesia. Histopathological examination revealed large tumor cells with eosinophilic, PAS-positive fine granules under the hyperplastic epithelium. The granular cells stained negatively with PTAH, but positively with S-100 protein. Electron microscopic observations revealed a number of lysosomes of various sizes and densities within the cytoplasm of the tumor cells.

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.

Malignant granular cell tumor

We report a case of malignant granular cell tumor of the chest wall that recurred in the right breast with axillary lymph node metastases. The recurrent tumor clinically and grossly mimicked a breast carcinoma. Electron microscopy and immunohistochemical techniques were used to confirm the cytologic and histologic diagnosis of granular cell tumor. The importance of true metastases in the diagnosis of malignant granular cell tumor and their differential diagnosis are discussed.

Malignant granular cell tumor of the breast

A primary malignant granular cell tumor (MGCT) in the breast is presented. The tumor showed mitoses, pleomorphism, necrosis and regional lymph node spread. While local excision is the best form of treatment, MGCT can spread rapidly to lymph nodes, lungs, liver, and bone. This lesion is an uncommon primary malignancy of breast with only 4 other cases reported.

Cytology of endobronchial granular cell tumor

Cytologic features of four cases of endobronchial granular cell tumor are presented. The diagnostic cells were found in bronchoscopically obtained material. They were arranged in smaller clusters and had finely granular cytoplasm with uniform oval or round nuclei. Frequently the cells are overlooked on regular cytologic examination owing to their benign nature. Nevertheless, there are enough cytomorphologic features that help to distinguish these cells from macrophages and bronchial epithelial cells. It is essential that the possibility of granular cell tumor is considered on cytologic examination. Final diagnosis, however, requires histologic verification.

Fibrous papule of the nose with granular cells: two cases

Two cases of fibrous papule of the nose (FPN) with granular cell features are presented and discussed. Both lesions have classic architectural features of FPN; however, the main stromal cells show large cytoplasmic granules of the type seen in granular cells. We are uncertain of the significance of these findings. Our hypotheses include a perifollicular granular cell reaction and a granular degenerative change of local dermal dendrocytes.