Pitfalls in odontogenic lesions and tumours: a practical guide

Lesions arising from odontogenic tissues of the jaws vary from very common to very rare. Some, such as radicular cysts, form a routine part of the diagnostic workload for histopathologists who report specimens from the head and neck, but many other lesions are rarely seen and can cause significant diagnostic difficulty for the non-specialist. These issues are compounded by the vagaries of dental disease (and terminology used by dentists and oral surgeons) and issues in the interpretation of radiographic images, which can be crucial to making a correct diagnosis. In this review article, we will discuss a number of areas of diagnostic difficulty, largely based on the authors experience in receiving tertiary referrals. This will focus on practical advice to help avoid the pitfalls in the diagnosis of odontogenic lesions.     

Fine-needle aspiration of a pleomorphic lipoma of the head and neck: a case report

Pleomorphic lipoma is a rare soft-tissue tumor, most commonly seen in the head and neck regions of middle-aged men. Fine-needle aspiration (FNA) of these lesions can present a diagnostic challenge. Its large, hyperchromatic cells and multinucleated forms (floret cells) can easily be mistaken for a malignancy. A patient with a round, well-circumscribed, painless, soft, subcutaneous posterior neck mass for 6 yr presented to our FNA clinic. Aspiration of the mass showed a hypocellular specimen with atypical large and floret cells with fragments of mature fibroadipose tissue in the background. Based on the clinical and cytomorphological findings, a diagnosis of pleomorphic lipoma was suggested, and it was confirmed on excision. This case highlights the need to be aware of unusual benign lesions that may arise in the head and neck region. Knowledge of these benign lesions will help in making the correct cytological diagnosis when these lesions are sampled by FNA.     

Distinctive soft tissue tumors of the head and neck.

Among soft tissue tumors as a whole, those in the head and neck region are relatively uncommon, and the proportion of all soft tissue sarcomas that arise in this region is 相似文献   

Is malignant melanoma arising in a Hutchinson's melanotic freckle a separate disease entity?

Several features which distinguish malignant melanoma arising in a Hutchinson's melanotic freckle (HMFM) from other types of malignant melanoma (MM) are described. Forty-eight patients with HMFM of the head and neck region were compared with 98 patients with MM of the head and neck region. All patients were clinical stage I. There was a preponderance of women amongst HMFM patients but not MM patients and HMFM patients were significantly older than MM patients. Although HMFM patients had thicker tumours than MM patients, these thicker lesions had a lower degree of mitotic activity and a higher incidence of partial regression. Overall prognosis for HMFM patients was significantly better than for MM patients, this being particularly so for women, none of whom died of melanoma. There was no close correlation between prognosis of HMFM patients and the thickness of their tumours. Every one of the HMFM in this study displayed evidence of severe solar degeneration, but such degeneration per se did not appear to confer upon these lesions their benign biological behaviour.     

Diagnostic value of GLUT-1 immunoreactivity to distinguish benign from malignant cystic squamous lesions of the head and neck in fine-needle aspiration biopsy material

The distinction of cystic squamous-cell carcinoma (SCC) from benign cystic squamous lesions (BCSLs) of the head and neck can be problematic on fine-needle aspiration biopsy (FNAB) material, particularly when BCSLs display epithelial reactive atypia or when SCC is well differentiated. Glucose transporter 1 (GLUT-1), a facilitative cell surface glucose transport protein, is aberrantly expressed in many cancers including oral and hypopharyngeal SCC. We evaluated the expression of GLUT-1 by immunochemistry on FNAB material to determine its value in distinguishing cystic SCC from BCSL of the head and neck. A 5-yr retrospective review of all head and neck cystic squamous lesions having FNAB specimens with cell block material, radiological studies, and histological confirmation was performed at our institution. Cell block material from 24 cystic squamous lesions, including 8 (33%) BCSL (7 branchial cleft cysts and 1 thyroglossal duct cyst[TDC]) and 16 (67%) metastatic SCCs with cystic/liquefactive degeneration, was retrieved and immunostained with anti-GLUT-1. GLUT-1 expression was considered positive when at least 10% of squamous cells exhibited distinct cell membrane reactivity. Positive GLUT-1 immunostaining was detected in all 16 SCCs and in none of the 8 BCSLs. In the carcinoma cases, the majority of malignant cells exhibited GLUT-1 reactivity; only a minor population of well-differentiated SCC cells displaying keratinization and arranged as squamous pearls did not express GLUT-1. GLUT-1 expression in cell block material can help to distinguish cystic SCCs from BCSLs of the head and neck. In conjunction with clinical and radiological correlation, GLUT-1 immunoreactivity can be an important diagnostic aid when the cytological findings are ambiguous.     

Benign epithelial neoplasms of the appendix: classification and clinical associations

The nomenclature of non-carcinoid epithelial proliferations of the appendix is confused and many of the terms used have no histogenetic basis. A classification based on the well-established diagnostic categories of colonic epithelial polyps has been proposed recently. We have applied this classification to 42 benign epithelial lesions of the appendix in order to determine its suitability for routine diagnostic use, and in order to determine the prognosis of patients with these lesions. All lesions could be classified as either hyperplastic, adenomatous, mixed hyperplastic/adenomatous or dilated appendices. Six cases were associated with a synchronous carcinoma of the colon with all types of appendiceal histology being represented. Follow-up of the remainder of the patients revealed two subsequent colonic carcinomas, at 3 and 6 years post-appendicectomy respectively. In both of these patients, the appendix had shown adenomatous epithelium. We suggest that adenomas of the appendix may have a similar prognostic significance to adenomas elsewhere in the large bowel.     

Fine Needle Aspiration Biopsies of the Head and Neck: The Surgical Pathologist's Perspective

Masses of the head and neck comprise a variety of benign and malignant tumors and tumor-like conditions, which may present diagnostic challenges to the surgical pathologist and surgeon. Fine needle aspiration cytology is an increasingly popular technique in the initial evaluation of such lesions. The high diagnostic accuracy of this technique makes it generally preferable to traditional surgical biopsy. It is particularly useful in the sampling of histologically uniform neoplasms of the salivary glands, identification of classical papillary carcinoma and medullary carcinoma of the thyroid, separation of colloid goiter from follicular neoplasms, and confirmation of clinically suspicious lymph node metastases in cases with already documented malignant diseases. Despite its usefulness, aspiration cytology of head and neck lesions has certain inherent pitfalls, and these are briefly examined in this review. Int J Surg Pathol 8(1):17-28, 2000     

Giant cell lesions of the jaws

Giant cell rich lesions are frequently encountered in the head and neck region, particularly within the jaw bones. Giant cell rich lesions often require a combination of the clinical presenting features, radiology, and histology to be taken into account before a definitive diagnosis can be achieved. Within this article we aim to highlight the key multinucleated giant cell lesions that show a predilection for the head and neck region, discussing the clinical presentation, radiographic appearance, histological findings, differential diagnosis and treatment options for such lesions.     

Fluorescence in-situ hybridization analysis for melanoma diagnosis

Melanocytic proliferation constitutes a heterogeneous group of lesions with remarkable differences in their biology and clinical outcome. Thus, accurate histological diagnosis of these cases is mandatory to establish the most appropriate surgical treatment and follow-up. Although histological examination alone is usually sufficient to identify melanomas among the greater number of nevi, the definition of the benign or malignant nature of a subset of melanocytic tumours, exhibiting atypical features, is a challenging task. Novel techniques that may assist in the histopathological diagnosis in difficult cases have been extensively researched over recent years. Fluorescence in-situ hybridization (FISH), performed with a panel of four probes, including three locus-specific identifier (RREB1, MYB, and CCND1) genes, seems to represent a sensitive and specific molecular tool for the diagnosis of non-ambiguous melanocytic lesions. Some studies have agreed that FISH may be an ancillary diagnostic instrument, but cannot replace light microscopy, to distinguish benign nevi from malignant melanomas in daily practice. However, in the context of ambiguous melanocytic tumours, results are still controversial, and additional and substantial work is needed to develop reliable probes that may identify, with high sensitivity, specific subsets of ambiguous melanocytic lesions, including spitzoid proliferation.     

Periductal mastitis in a male breast masquerading as lobular carcinoma on fine needle aspiration cytology

Fine needle aspiration cytology (FNAC) is quite successful in identifying specific benign and malignant breast lesions, but its role in the categorization of proliferative breast lesions has not been well defined. Mastitis/ breast abscess can lead to intense inflammatory response; however, its association with epithelial hyperplasia is rarely reported. At times, it may be difficult to differentiate dense lymphoplasmacytic infiltrate from non-Hodgkin's lymphoma. We present a case of periductal mastitis associated with epithelial hyperplasia, presenting as a subaerolar swelling in a male breast, which was misinterpreted as lobular carcinoma on FNAC.     

Special tumours of the head and neck

Most lesions encountered by surgical pathologists in the head and neck region are benign and malignant proliferations of the squamous mucosa. However, there are some uncommon tumours arising from specialized epithelium and stroma of this region. These lesions include Schneiderian papilloma, low-grade sinonasal adenocarcinoma, intestinal-type sinonasal adenocarcinoma, sinonasal undifferentiated carcinoma, olfactory neuroblastoma, nasopharyngeal angiofibroma, sinonasal haemangiopericytoma, neuroendocrine adenoma of the middle ear, and endolymphatic sac tumour. Given the rarity of these tumours, a crucial key for their correct diagnosis is a keen awareness of their morphologic and immunohistochemical features. In this review, we attempt to present some salient or recent clinicopathologic and prognostic findings of these fascinating neoplasms.     

Giant cell tumor of temporomandibular joint presenting as a parotid tumor: Challenges in the accurate subclassification of giant cell tumors in an unusual location

Fine needle aspiration is frequently used as the initial diagnostic procedure in the work‐up of head and neck lesions, including soft tissue masses and salivary gland neoplasms. Giant cell tumors (GCTs), both osseous and extraosseous, are benign tumors that occur, albeit rarely, in the head and neck region. Extraosseous GCTs may be further classified based on their tissue of origin and specific anatomic location. Regardless of location, giant cell tumors are morphologically similar and share cytologic and histologic diagnostic criteria. Evaluation of imaging is therefore essential to the correct classification of these tumors. Accurate diagnosis is crucial since the clinical behavior and treatment is significantly different among the subtypes of GCTs. The case presented herein illustrates the diagnostic dilemma between two uncommon entities in an unusual site: GCT of parotid gland and tenosynovial GCT.     

Application of Ultrasound-guided Core Biopsy in Head and Neck

Head and neck tumor is frequently encountered clinically, but the list of differential diagnosis of neck lumps is lengthy. Consequently, the major concern of diagnostic procedure is to effectively narrow the possibility, and finally make an accurate diagnosis. Ultrasound-guided core biopsy (USCB) has been well established in many medical fields as the standard tissue sampling procedure, with less harm than open biopsy (OB) and more pathological information than ultrasound-guided fine needle aspiration (USFNA). In addition, using the small-cutting needle, USCB can be easily and safely performed for head and neck lesions. In this review, we present our optimal procedure of applying USCB and review its roles in head and neck, including cervical lymph nodes, thyroid tumors, salivary tumors, pediatric head and neck lesions, cervical infectious diseases, head and neck cancer and aerodigestive tumors. The procedure-related bleeding and tumor seeding are rarely reported even after 7-year follow up in the literature. The head and neck surgeons are competent to take care of any unpredictable complications caused by USCB. According to our experience, USCB can be utilized as a powerful tool in surgeon’s hands to explore the possibilities of doing tissue sampling in many areas of head and neck.     

Inflammatory pseudotumour of soft tissues: a clinicopathological and immunohistochemical analysis of 18 cases

Pseudosarcomatous proliferations of myofibroblasts. fibroblasts and inflammatory cells have been reported in a wide variety of sites and are most commonly termed idammatory pseudotumours. Despite increasing recognition, the occurrence of inflammatory pseudotumour in somatic soft tissue is poorly documented, such that these lesions are commonly mistaken for a variety of benign and malignant neoplasms. This report documents our experience of 18 cases of soft tissue inflammatory pseudotumour. All arose in adults (median age 54.5 years: range 28-83 years) and showed no sex predilection. Anatomical location was varied but the head and neck region and abdominal cavity were most common. They displayed a spectrum of histological appearances but all were characterized, to a greater or lesser extent, by an admixture of myofibroblasts and fibroblasts, most commonly arranged in short interwoven fascicles, together with a polymorphic inflammatory cell component, consisting principally of lymphocytes and plasma cells. In some cases xanthoma cells were prominent. Simple surgical excision appeared to be curative. The importance of recognizing the presence of a wide clinicopathological spectrum is emphasized and the differential diagnosis, especially from fibrohistiocytic neoplasms or Hodgkin's disease, is discussed.     

Non-epithelial neoplasms of the prostate

Non-epithelial prostatic neoplasms are infrequent and cover a broad array of entities that include both benign and highly aggressive tumours. Because they are very infrequent, there is often limited understanding of them, and the recognition of these entities, when encountered, may pose a diagnostic challenge, owing to histological overlap between them or their rarity. Most lesions in this category are mesenchymal in origin, such as prostatic stromal tumours arising from specialized prostatic stroma, smooth muscle tumours, both benign and malignant, and solitary fibrous tumours. Less commonly occurring tumours include neural, germ cell and melanocytic tumours that may be derived from cells not normally present in the prostate. Some tumours have well-established extraprostatic counterparts and, when encountered, are more commonly extraprostatic/secondary in origin; these include gastrointestinal stromal tumours and most haematopoietic tumours. The majority of tumours are characterized by a spindle cell pattern with significant overlap in morphological features. In this setting, appropriate use of immunohistochemistry and molecular studies are often necessary for accurate diagnosis, prognosis, or prediction for therapy. This review addresses and updates the clinicopathological features of the entire spectrum of non-epithelial tumours with an approach to the histological diagnosis.     

Benign hepatocellular lesions and neoplasms: a comprehensive review

The prevalence of benign mass-forming liver lesions has significantly increased in recent years due to advances in diagnostic imaging. In general, these lesions can be either neoplastic or nonneoplastic and carry a different prognosis and management. Among benign mass-forming lesions of the liver, hemangiomas are the most common, followed by focal nodular hyperplasia, which is encountered ten times more frequently than adenomas. Hepatocellular adenomas are the third most common benign tumor of the liver. Their classification was revised in 2016 based on histomorphology and molecular signatures and includes hepatocyte nuclear factor-1 alpha (HNF1A)-mutated hepatocellular adenomas, beta-catenin 1 (CTNNB1) gene–mutated hepatocellular adenomas, interleukin-6 signal transducer gene–mutated or inflammatory/telangiectatic hepatocellular adenomas, and unclassified hepatocellular adenomas. Since then, a new subtype has been discovered, decreasing the proportion of unclassified cases. Hepatocellular adenomas have different molecular characteristics, behavior, and management, depending on the subtype. The telangiectatic subtype tends to bleed and may cause hemoperitoneum whereas the beta-catenin mutated subtype can progress to malignancy and is surgically resected independent of the size or symptoms. Other hepatic lesions include nodular regenerative hyperplasia, which occurs in the setting of blood flow alterations; and focal fatty change or benign steatotic nodules. Lastly, epithelioid angiomyolipomas are very uncommon benign mesenchymal liver tumors that belong to a family of tumor arising from perivascular epithelioid cells (PEComas) either sporadically or in the setting of tuberous sclerosis. Herein, we review these benign hepatic lesions and neoplasms and discuss the histomorphology and immunohistochemistry that allow us to render a specific diagnosis.     

Is the carbohydrate sialosyl-Tn a marker for altered,non-malignant activity in squamous epithelium in the head and neck region?

Cell surface carbohydrates are involved in many cell functions such as cellular differentiation, adhesion, and invasion. A carbohydrate, sialosyl-Tn (STn), is expressed in many human carcinomas but generally not in normal epithelia. In the oral mucosa, however, STn had recently been observed on basal cell in some lesions with epithelial hyperplasia and dysplasia. The aim of this study was to carry out a systematic investigation of STn expression on epithelial basal cells in hyperplastic, ‘borderline’ malignant, and malignant head and neck lesions, to see if the expression of STn is associated specifically with hyperplastic conditions. Using the primary monoclonal antibody TKH2, normal controls did not reveal STn. STn was detected on probably post-mitotic basal cells in hyperplastic head and neck lesions and on basal cells adjacent to cancers, but not within the carcinomas. A Ki67 antibody reacted with basal cells in other locations. The most highly differentiated lesions, such as focal epithelial hyperplasia and verrucous hyperplasia, revealed a high percentage (86 per cent in both cases) of STn reactivity. The least-differentiated verrucous carcinomas (VCs) and keratoacanthomas (KAs) did not express STn, in contrast to the highly differentiated VCs and KAs. These findings indicate that STn-negative cases may have a greater malignant potential that the STn-positive cases. In conclusion, STn expressed on basal cells is possibly a marker for non-malignant conditions with altered basal cell activity and for highly differentiated verrucous carcinomas.     

Selected problems in fine needle aspiration of head and neck masses.

A wide variety of masses in the head and neck, including those in the major salivary glands, can be approached by fine needle aspiration. In many instances, a correct definitive diagnosis con be rendered after examination of smears or cell block material. However, several significant but uncommon areas can lead to diagnostic difficulties, with the potential for clinically important diagnostic errors. Many of these occur in salivary gland lesions. The most frequent problems involve variations in the expected cytology of pleomorphic adenoma. Then, there are several benign-malignant "look-alike" pairs of lesions. The first of these is related to small-cell epithelial neoplasms of low nuclear grade; the most frequent problem is between basal cell adenomas and adenoid cystic carcinoma, particularly the solid (anaplastic) type. The next area contrasts mucoepidermoid carcinoma with its cytologic mimic, benign salivary gland duct obstruction. The final difficulty in salivary gland aspiration contrasts large-cell epithelial lesions of low nuclear grade: oncocytic proliferations and acinic cell carcinoma. The clinical implications of cytologically benign squamous cell-containing cyst aspirates from the lateral neck will be discussed. Finally, a brief consideration of methodological optimization for thyroid aspirations will be offered.     

Juvenile xanthogranuloma of the nasal cavity

JXG is a benign lesion of unknown incidence. It is the most frequent type of non-langerhans histiocytosis with a median age of 2 years. It usually presents as isolated cutaneous lesions. Multiple lesions, especially over the head and neck, may occur. The skin lesions tend to regress slowly with time. Extra-cutaneous and visceral involvements have been observed, the most common site being the eye. When the lesions are numerous, they may persist, hence the need for treatment with corticosteroids or chemotherapy. Histologically, the lesion consists of histiocytes admixed with an inflammatory infiltrate of variable density. The lesions are initially monomorphic and very cellular, progressively enriched with multinucleated giant cells of Touton and foamy cells, followed by spindle cells. We report an 8-year old girl with JXG of early type without multinucleated and foamy cells. This case presented as a tumour in the inferior meatus of nasal cavity, clinically simulating a rhabdomyosarcoma. This atypical clinical and histological presentation with benign evolution should be recognized since it requires only local treatment.     

Cystic change in metastatic lymph nodes: a common diagnostic pitfall in fine-needle aspiration cytology

Fine-needle aspiration cytology (FNAC) of cystic metastases is a challenging diagnostic category and has been investigated in a limited number of malignancies and sites. The present study retrospectively reviewed 1,211 FNAC of superficial masses, including lymph nodes (1,102 aspirates), benign cystic lesions (64 aspirates), and lymphocysts (45 aspirates) with the aim of determining the tumors that cause cystic change in metastases. Cytology results from 1,102 lymph node aspirations were suspicious or positive for malignancy in 541 specimens (49.1%), benign in 230 (20.9%), and unsatisfactory in 331 (30%). There were 28 malignant aspirates demonstrating cystic change (5.2%). The tumor type that most frequently caused cystic change was thyroid papillary carcinoma (42.8% of cases), followed by squamous cell carcinoma (primary in the head and neck region 30.8% and in the skin 24%), tumors of unknown origin (6.3%), serous papillary carcinoma of the ovary or endometrium (4.8%), and malignant melanoma (2.1%). Cystic change was observed most commonly in the head and neck region lymph nodes (60%). The most challenging lesions to assess using FNAC were metastatic lymph nodes showing cystic change, accounting for six of the 16 false-negative diagnoses and one false-positive diagnosis. The results of this study suggest that cystic change in metastatic lymph nodes occurs in certain types of tumors and is an important cause of diagnostic error. FNAC should be repeated in case of suspicious hypocellular cystic aspirations, especially in patients with known malignancy.