Developing Classifications of Laryngeal Dysplasia: The Historical Basis

During the last 60 years numerous significant attempts have been made to achieve a widely acceptable terminology and histological grading for laryngeal squamous intraepithelial lesions. While dysplasia was included in the pathology of the uterine cervix already in 1953, the term dysplasia was accepted in laryngeal pathology first after the Toronto Centennial Conference on Laryngeal Cancer in 1974. In 1963 Kleinsasser proposed a three-tier classification, and in 1971 Kambic and Lenart proposed a four-tier classification. Since then, four editions of the World Health Organisation (WHO) classification have been proposed (1978, 1991, 2005 and 2017). Several terms such as squamous intraepithelial neoplasia (SIN) and laryngeal intraepithelial neoplasia (LIN) are now being abandoned and replaced by squamous intraepithelial lesions (SIL). The essential change between the 2005 and 2017 WHO classifications is the attempt to induce a simplification from a four- to a two-tier system. The current WHO classification (2017) thus recommends the use of a two-tier system with reasonably clear histopathological criteria for the two groups: low-grade and high-grade dysplasia. Problems with interobserver variability apart, subjectivities and uncertainties remain, but to a lesser degree. Ongoing and additional molecular studies may help to clarify underlying events that will increase our understanding and possibly can facilitate our attempts to obtain an even better classification. The classification needs to be easier for the general pathologist to perform and easier for the clinician to interpret. These two objectives are equally important to provide each patient the best personalised treatment available for squamous intraepithelial lesions.

Update on Neuroendocrine Carcinomas of the Larynx

OBJECTIVES

Laryngeal neuroendocrine carcinomas are heterogeneous neoplasms characterized by neuroendocrine differentiation. Their prognoses are dependent on tumor type, therefore different classifications have been developed. Moreover, other tumors have overlapping pathologic features posing a range of diagnostic possibilities.

METHODS

A review of the literature was performed to comprehensively understand the classification and diagnosis of these tumors.

RESULTS

We review the past and present classification systems, with emphasis to the latest 2017 World Health Organization Classification of Head and Neck Tumors. We highlight salient clinicopathologic features and discuss the presumptive etiologic role of human papilloma virus. We share a practical algorithmic approach to the diagnosis of suspected neuroendocrine neoplasms of the larynx including a novel marker for neuroendocrine differentiation, insulinoma-associated protein 1.

CONCLUSIONS

Accurate diagnosis and grading of laryngeal neuroendocrine carcinomas is critical for prognostication and therapeutic decision making. The use of an algorithm is instrumental in assuring the exclusion of mimickers.

Ectomesenchymal Chondromyxoid Tumor: A Neoplasm Characterized by Recurrent RREB1-MKL2 Fusions

Ectomesenchymal chondromyxoid tumor is a rare and benign neoplasm with a predilection for the anterior dorsal tongue. Despite morphologic heterogeneity, most cases are characterized by a proliferation of bland spindle cells with a distinctive reticular growth pattern and myxoid stroma. The immunophenotype of these neoplasms is likewise variable; most cases express glial fibrillary acid protein and S100 protein, with inconsistent reports of keratin and myoid marker expression. The molecular pathogenesis is poorly understood; however, a subset of cases has been reported to harbor EWSR1 gene rearrangement. Following identification of an RREB1-MKL2 fusion gene by RNA Sequencing in an index patient, a retrospective review of additional cases of ectomesenchymal chondromyxoid tumors was performed to better characterize the clinical, immunohistochemical, and molecular attributes of this neoplasm. A total of 21 cases were included in this series. A marked predisposition for the dorsal tongue was confirmed. Most cases conformed to prior morphologic descriptions; however, hypercellularity, hyalinized stroma, and necrosis were rare attributes not previously emphasized. The neoplastic cells frequently coexpressed glial fibrillary acid protein, S100 protein, keratin, smooth muscle actin, and/or desmin; a single case was found to contain significant myogenin expression. An RREB1-MKL2 fusion product was identified in 19 tumors (90%), a single tumor (5%) had an EWSR1-CREM fusion product, and the remaining case lacked any known fusion gene by RNA Sequencing. The latter 2 cases subtly differed morphologically from many in the cohort. This series illustrates that recurrent RREB1-MKL2 fusions occur in most, perhaps all, cases of ectomesenchymal chondromyxoid tumor.

Data Set for the Reporting of Carcinomas of the Major Salivary Glands: Explanations and Recommendations of the Guidelines From the International Collaboration on Cancer Reporting

The International Collaboration on Cancer Reporting is a nonprofit organization whose goal is to develop evidence-based, internationally agreed-upon standardized data sets for each anatomic site, to be used throughout the world. Providing global standardization of pathology tumor classification, staging, and other reporting elements will lead to achieving the objective of improved patient management and enhanced epidemiologic research. Salivary gland carcinomas are relatively uncommon, and as such, meaningful data about the many histologic types are not easily compared. Morphologic overlap between tumor types makes accurate classification challenging, but there are often significant differences in patient outcomes. Therefore, issues related to tumor type, tumor grading, high-grade transformation, extent of invasion, number and size of nerves affected, and types of ancillary studies are discussed in the context of daily application to specimens from these organs. This review focuses on the data set developed for salivary gland carcinomas with discussion of the key core and noncore elements developed for inclusion by an international expert panel of head and neck and oral-maxillofacial pathologists and surgeons.

Incidental findings of thyroid tissue in cervical lymph nodes: old controversy not yet resolved?

The clinical significance of papillary or follicular thyroid tissue incidentally discovered in cervical lymph nodes during pathological assessment of neck dissections for non-thyroid cancers of the upper aero-digestive tract is critically reviewed. Special emphasis is given to controversies over normal-looking, nodal, thyroid follicles. Arguments for and against the benign nature of these follicles are considered together with processes that could be involved in their formation. The admittedly limited evidence suggests that benign, thyroid follicular inclusions rarely occur in cervical lymph nodes. Histological criteria that could be helpful in recognizing the inclusions, which include assessing their extent in conjunction with the size of the node, are discussed. Finally, an algorithm based on collaboration between specialists, correlating histological findings with imaging and loco-regional control of the upper aero-digestive tract cancer, is suggested for the management of patients with incidentally discovered, nodal thyroid tissue.

Cervical lymph node metastasis in adenoid cystic carcinoma of oral cavity and oropharynx: A collective international review

The purpose of this study was to suggest general guidelines in the management of the N0 neck of oral cavity and oropharyngeal adenoid cystic carcinoma (AdCC) in order to improve the survival of these patients and/or reduce the risk of neck recurrences. The incidence of cervical node metastasis at diagnosis of head and neck AdCC is variable, and ranges between 3% and 16%. Metastasis to the cervical lymph nodes of intraoral and oropharyngeal AdCC varies from 2% to 43%, with the lower rates pertaining to palatal AdCC and the higher rates to base of the tongue. Neck node recurrence may happen after treatment in 0-14% of AdCC, is highly dependent on the extent of the treatment and is very rare in patients who have been treated with therapeutic or elective neck dissections, or elective neck irradiation. Lymph node involvement with or without extracapsular extension in AdCC has been shown in most reports to be independently associated with decreased overall and cause-specific survival, probably because lymph node involvement is a risk factor for subsequent distant metastasis. The overall rate of occult neck metastasis in patients with head and neck AdCC ranges from 15% to 44%, but occult neck metastasis from oral cavity and/or oropharynx seems to occur more frequently than from other locations, such as the sinonasal tract and major salivary glands. Nevertheless, the benefit of elective neck dissection (END) in AdCC is not comparable to that of squamous cell carcinoma, because the main cause of failure is not related to neck or local recurrence, but rather, to distant failure. Therefore, END should be considered in patients with a cN0 neck with AdCC in some high risk oral and oropharyngeal locations when postoperative RT is not planned, or the rare AdCC-high grade transformation.

Cervical Lymph Node Metastasis in High-Grade Transformation of Head and Neck Adenoid Cystic Carcinoma: A Collective International Review

Adenoid cystic carcinoma (AdCC) is among the most common malignant tumors of the salivary glands. It is characterized by a prolonged clinical course, with frequent local recurrences, late onset of metastases and fatal outcome. High-grade transformation (HGT) is an uncommon phenomenon among salivary carcinomas and is associated with increased tumor aggressiveness. In AdCC with high-grade transformation (AdCC–HGT), the clinical course deviates from the natural history of AdCC. It tends to be accelerated, with a high propensity for lymph node metastasis. In order to shed light on this rare event and, in particular, on treatment implications, we undertook this review: searching for all published cases of AdCC-HGT. We conclude that it is mandatory to perform elective neck dissection in patients with AdCC-HGT, due to the high risk of lymph node metastases associated with transformation.

Salivary acinic cell carcinoma: reappraisal and update

Epidemiologic and clinicopathologic features, therapeutic strategies, and prognosis for acinic cell carcinoma of the major and minor salivary glands are critically reviewed. We explore histopathologic, histochemical, electron microscopic and immunohistochemical aspects and discuss histologic grading, histogenesis, animal models, and genetic events. In the context of possible diagnostic difficulties, the relationship to mammary analog secretory carcinoma is probed and a classification is suggested. Areas of controversy or uncertainty, which may benefit from further investigations, are also highlighted.

Neuroendocrine neoplasms of the sinonasal region

Neuroendocrine neoplasms of the sinonasal region, which are relatively uncommon but clinically very important, are reviewed here in the light of current knowledge. Using a definition for neuroendocrine based on phenotypic, histologic, immunohistochemical, and electron microscopic features rather than histogenetic criteria, sinonasal neuroendocrine carcinomas are examined with a particular emphasis on the small-cell and large-cell subtypes. This is followed by revisiting olfactory neuroblastoma because it is also a tumor that shows a neuroendocrine phenotype. Kadish clinical and Hyams histologic grading systems as prognosticators of olfactory neuroblastoma are also considered in detail. Finally, controversies regarding sinonasal undifferentiated carcinoma as a neuroendocrine tumor are discussed and a possible relationship with high-grade olfactory neuroblastoma is explored. Genetic events and current management of these tumors are also outlined. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2259-E2266, 2016.

Rhabdomyoblastic Differentiation in Head and Neck Malignancies Other Than Rhabdomyosarcoma

Rhabdomyosarcoma is a relatively common soft tissue sarcoma that frequently affects children and adolescents and may involve the head and neck. Rhabdomyosarcoma is defined by skeletal muscle differentiation which can be suggested by routine histology and confirmed by immunohistochemistry for the skeletal muscle-specific markers myogenin or myoD1. At the same time, it must be remembered that when it comes to head and neck malignancies, skeletal muscle differentiation is not limited to rhabdomyosarcoma. A lack of awareness of this phenomenon could lead to misdiagnosis and, subsequently, inappropriate therapeutic interventions. This review focuses on malignant neoplasms of the head and neck other than rhabdomyosarcoma that may exhibit rhabdomyoblastic differentiation, with an emphasis on strategies to resolve the diagnostic dilemmas these tumors may present. Axiomatically, no primary central nervous system tumors will be discussed.

Salivary gland tumor "wishes" to add to the next WHO Tumor Classification: sclerosing polycystic adenosis, mammary analogue secretory carcinoma, cribriform adenocarcinoma of the tongue and other sites, and mucinous variant of myoepithelioma

This review is a continuation of suggested tumor additions to the next WHO Tumor Classification. The author will focus on four salivary gland entities that have recently become accepted in the literature as new neoplastic entities: sclerosing polycystic adenosis, mammary analogue secretory carcinoma, cribriform adenocarcinoma of the tongue and other sites, and mucinous variant of myoepithelioma.

Moderately differentiated neuroendocrine carcinoma (atypical carcinoid) of the parotid gland: report of three cases with contemporary review of salivary neuroendocrine carcinomas

Primary neuroendocrine carcinomas (NECs) of the salivary glands are rare. Most reported NECs in that region are small cell carcinomas with few cases of large cell undifferentiated carcinoma and typical carcinoid tumors. Only two moderately differentiated NECs (atypical carcinoid tumors) have been previously reported. In the current series, the authors report three additional moderately differentiated NECs (atypical carcinoid tumors) of the parotid gland; two occurred in women and one in a man. All patients were initially treated with parotidectomy, with selective lymph node excision in one, and radiation therapy in another. Follow-up was available for two cases (18 and 79 months). One patient had two local recurrences, developing lymph node and liver metastases requiring further surgery and chemotherapy. Currently, she is alive with disease, on supportive care. The second patient is alive with no signs of recurrence. Patients' work-up excluded the possibility of metastatic NECs to the salivary glands in all cases. Histologically, the tumors demonstrated infiltrating nests, cords and trabeculae of round, oval to spindle shaped cells with moderate to focally abundant eosinophilic cytoplasm, small to prominent nucleoli and chromatin stippling. Scattered rosette-like structures were prominent in one tumor. The highest mitotic counts for the three tumors ranged from 5 to 8 mitotic figures/10 hpfs. Necrosis, focal but distinct, was noted in two tumors, vascular invasion in two tumors and perineural invasion in one tumor. Immunohistochemical staining was diagnostic of neuroendocrine carcinoma, showing uniform positive labeling with broad-spectrum cytokeratin (with a paranuclear punctuate pattern in one case), chromogranin and synaptophysin antibodies. CK20 was negative in two tumors and stained rare cells (<1%) in the third.

Mucinous myoepithelioma, a recently described new myoepithelioma variant

Myoepithelial neoplasms are tumors composed almost exclusively of cells with myoepithelial differentiation. They frequently contain spindle, plasmacytoid or epithelioid shaped cells and may have oncocytic or clear cytoplasmic features. They are uncommon, accounting for 1.5 % of all salivary gland tumors and for 2.2-5.7 % of major and minor salivary gland tumors, respectively. Recently this author, together with several colleagues, have described three unusual myoepithelial tumors, two benign and one malignant that contained abundant intracellular mucin material, which they termed the mucinous variant of myoepithelioma. This represents a unique, previously undescribed subtype that does not fit in the current classification system. A literature review revealed several similar cases reported as "signet ring-cell" adenocarcinomas of salivary gland, which stained for myoepithelial markers, in addition to containing intracellular mucin material, that are more accurately classified as mucinous myoepithelioma. To date, there are 17 reported mucinous myoepitheliomas; four were classified as benign and 13 as malignant. Thirteen arose in minor salivary glands and four in the parotid gland. One patient presented with a lymph node metastasis. With minimal follow-up currently available, this appears to be a benign to low-grade malignancy.

Molecular diagnostic alterations in squamous cell carcinoma of the head and neck and potential diagnostic applications

Head and neck squamous cell carcinoma (HNSCC) is a common malignancy that continues to be difficult to treat and cure. In many organ systems and tumor types, there have been significant advances in the understanding of the molecular basis for tumorigenesis, disease progression and genetic implications for therapeutics. Although tumorigenesis pathways and the molecular etiologies of HNSCC have been extensively studied, there are still very few diagnostic clinical applications used in practice today. This review discusses current clinically applicable molecular markers, including viral detection of Epstein-Barr virus and human papillomavirus, and molecular targets that are used in diagnosis and management of HNSCC. The common oncogenes EGFR, RAS, CCND1, BRAF, and PIK3CA and tumor suppressor genes p53, CDKN2A and NOTCH are discussed for their associations with HNSCC. Discussion of markers with potential future applications is also included, with a focus on molecular alterations associated with targeted therapy resistance.

Are biosafety practices in anatomical laboratories sufficient? A survey of practices and review of current guidelines

Biosafety practices in anatomical pathology laboratories are crucial to prevent unnecessary exposures to both chemical and biological agents. Regulatory and guidance agencies have general regulations and recommendations regarding anatomical pathology laboratory biosafety practices. This study aimed to determine if professionals' perceptions and actual practice mirror these guidelines. Current available regulations and recommendations for biosafety practices in anatomical pathology laboratories were reviewed and used to construct a brief, validated online survey distributed to anatomical pathology professionals. The survey was completed by 39 survey participants in pathology departments from diverse institutions. An average of 44% of respondents reported receiving inadequate biosafety training. At survey initiation, 61.5% of respondents felt that the risks of chemical and infectious disease exposures had been clearly explained to them; however, by completion of the survey, only 21% believed risks to be clearly explained. Respondents use a variety of personal protective equipment, yet only 60% would have been classified as meeting recommendations. Most respondents reported having a needle stick or cut (56.3%) or formalin exposure by splash or prolonged direct skin contact (62.5%). The survey indicated that there is a dire need for improved training in anatomical pathology biosafety as daily practices do not reflect current guidelines. In addition, improved training on exposure risks, including needle-stick injuries, personal protective equipment, and chemical hazards, is needed. Finally, the success of this training should be monitored locally as regulatory agency requirements do not seem to alter daily practice.

Salivary mucoepidermoid carcinoma: a multi-institutional review of 76 patients

Mucoepidermoid carcinoma (MEC) is a relatively common salivary tumor with varying potential for aggressive behavior. Mucoepidermoid carcinoma grading has evolved from descriptive two-tiered schemata to more objective three-tiered systems. In 2001, we published a grading system Brandwein et al. in Am J Surg Pathol 25:835-845, (2001) which modified the prevailing criteria of Auclair et al. in Cancer 69:2021-2030 (1992), and included additional features of aggressive MEC. Here we seek to validate our modified grading system in a new multicenter cohort. The retrospective cohort consisted of 76 patients with confirmed MEC and known outcome data. The resection specimens were reviewed and uniformly graded according to our modified criteria Brandwein et al. in Am J Surg Pathol 25:835-845 (2001), and the Auclair criteria Auclair et al. in Cancer 69:2021-2030, (1992), Goode et al. in Cancer 82:1217-1224, (1998). Case distribution was as follows: Montefiore Medical Center: 41 (1977-2009), University of Alabama at Birmingham: 21 (1999-2010), and Rhode Island Hospital: 14, (1995-2011). Patient age ranged from 7 to 81 years (mean 51 years). The female to male ratio was 3:1. The most commonly involved sites were: parotid: n = 39 (51%), palate: n = 10 (13%), retromolar trigone: n = 6 (8%), buccal: n = 5 (7%), and submandibular gland: n = 5 (7%). The modified criteria upgraded 41% MEC; 20/25 MEC from AFIP Grade 1 to Grade 2 and 5/25 from AFIP grade 1 to grade 3. Eleven patients had positive lymph nodes; the AFIP MEC grade for cases were: grade 1-3/11, Grade 2-1/11, and grade 3-7/11; the modified grading criteria distribution for these cases were Grade 1: 0/11, grade 2: 1/11, and grade 3: 10/11. Nine patients developed disease progression after definitive treatment. High-stage and positive lymph node status were significantly associated with disease progression (p = 0.0003 and p < 0.0001, respectively). For the nine patients with disease progression, the modified grading schema classified eight MEC as grade 3 and one as grade 2. By comparison, the AFIP grading schema classified three of these MEC as grade 1, and the remaining six as grade 3. Despite the fact that this multicenter retrospective study accrued 76 patients with outcome, the predictive performance of the two grading schema could not be compared due to the few patients who experienced disease progression and were also reclassified with respect to grade (n = 3).

My journey into the world of salivary gland sebaceous neoplasms

As part of this symposium honoring Leon Barnes, the authors were asked to present the case from which they learned the most. I chose a cystic sebaceous lymphadenoma (SL) as my case presentation. This paper presents this unusual case, as well as several additional sebaceous tumors that came across my desk the first few years I was in practice. These interesting cases led me to thoroughly review the literature on sebaceous tumors of the salivary glands, resulting in several publications, the largest series of sebaceous tumors published at this time as well as a careful review of all cases in the literature. The author will also review the current and previous literature on the five types of salivary gland sebaceous tumors: sebaceous adenoma, SL (and non-sebaceous lymphadenoma), sebaceous carcinoma, sebaceous lymphadenocarcinoma, and sebaceous differentiation in other types of salivary gland lesions.

Terminology and classification of neuroendocrine neoplasms of the larynx

OBJECTIVES

To review the history and literature on neuroendocrine neoplasms of the larynx and discuss the terminology and classification of these tumors.

STUDY DESIGN

Contemporary review.

METHODS

Published journal articles identified through PubMed and conference proceedings were reviewed.

RESULTS

Neuroendocrine neoplasms of the larynx include both epithelial (carcinomas) and neural-type lesions (paragangliomas).The nomenclature of these tumors has changed quite a bit over time, but recently, clearer categories have emerged that are biologically meaningful. They can overlap clinically and histologically so that segregation into the clinically relevant subtypes can be difficult, but it is extremely important to do so as they have a wide range of behaviors going from benign to rapidly fatal.

CONCLUSIONS

Neuroendocrine neoplasms of the larynx can be clearly categorized into the five tumor types: typical carcinoid, atypical carcinoid, small cell neuroendocrine carcinoma, large cell neuroendocrine carcinoma, and paraganglioma. These have concrete biologic and clinical significance and clearly dictate patient treatment.

Primary mucin-producing tumours of the salivary glands: a clinicopathological and morphometric study

AIMS

To determine clinicopathological and morphometric features that discriminate between mucin-producing primary salivary gland carcinomas.

MATERIALS AND RESULTS

Fifteen mucin-producing tumours were stratified into five colloid carcinomas (CCs), four mucinous cystadenocarcinomas (MCAs), three mucin-rich salivary duct carcinomas (SDCs) and three mucin-rich mucoepidermoid carcinomas (MECs). The mean patient age was 70, 58, 43 and 63 years for CC, MCA, SDC and MEC, respectively. Eleven of 15 patients were female. The majority of CC cases originated from major salivary glands; MCA showed a predilection for the minor salivary glands. No disease-related mortality was observed in the CC group; one patient died in the MCA group, and one in the SDC group. Receiver-operating characteristic curve analysis revealed an optimal cut-off point of 17% of the tumour cells in contact with stroma that best distinguished between the CC and MCA. Histomorphometric measurements revealed that CC was best differentiated from MCA by smaller nuclear size and more regular chromatin.

CONCLUSIONS

Strict morphological criteria of CC coupled with assessment of the tumour cell/stroma relationship and the nuclear features facilitate discrimination between mucinous tumours of salivary gland.

Seromucinous hamartomas: a clinicopathological study of a sinonasal glandular lesion lacking myoepithelial cells

AIMS

To describe seven cases of sinonasal seromucinous hamartoma.

MATERIALS AND RESULTS

The clinicopathological and immunohistochemical features of seven seromucinous hamartomas were analysed. There were four men and three women. Six lesions involved the posterior nasal septum and one the lateral wall. Size ranged from 6 to 40 mm. Four patients had no recurrences. One patient had local recurrences 24 and 60 months after diagnosis. The masses were covered by respiratory epithelium. Their stroma was oedematous to fibrous and contained invaginated respiratory epithelium forming glands and cysts, cysts with cuboidal to flat epithelium, and small serous glands, ducts and tubules with lobular and irregular haphazard patterns. One case had numerous glands surrounded by hyalinized basement membrane with features of respiratory epithelial adenomatoid hamartoma (REAH). One case had focal REAH-like changes. Both respiratory and serous components were positive for cytokeratin (CK) 7 and CK19. The serous component lacked myoepithelial cells when stained for CK14, p63, calponin and muscle-specific antigen in five cases.

CONCLUSIONS

Seromucinous hamartomas show a broader histopathological appearance than previously reported. The serous proliferation in these lesions lacks myoepithelial cells. The presence of occasional REAH-like features and common location in the posterior nasal septum suggest a spectrum from pure seromucinous hamartoma to REAH.

Mucoepidermoid carcinoma arising in a background of sialadenoma papilliferum: a case report

Sialadenoma papilliferum is a rare tumor, primarily of minor salivary gland origin, first described by Abrams and Finck (Cancer 24:1057-63, 1969). It is both an exophytic and endophytic papillary lesion histologically resembling syringocystadenoma papilliferum of sweat gland. The tumor is considered benign although rare recurrent cases have been reported. Three cases of malignant transformation of sialadenoma papilliferum have been described in the literature. We report a high grade mucoepidermoid carcinoma arising in a background of sialadenoma papilliferum, at the base of the tongue, an unusual location for minor salivary gland neoplasms. Eleven months after excision and nodal dissection, there is no evidence of recurrence or metastasis.

Alveolar rhabdomyosarcoma of the head and neck region in older adults: genetic characterization and a review of the literature

Alveolar rhabdomyosarcoma is remarkably rare in adults older than 45 years. Initial immunoprofiling of a small cell neoplasm of the head and neck region in an older adult may not include myogenic markers. A valuable diagnostic aid and important prognostic parameter in alveolar rhabdomyosarcoma is the identification of PAX3-FOXO1 [t(2;13)(q35;q14)] or PAX7-FOXO1 [t(1;13)(p36;q14)] rearrangements. The purpose of this study was to document the clinicopathologic, immunophenotypic, and genetic features of head/neck alveolar rhabdomyosarcoma in older adults. Prior isolated descriptions of 3 patients were included. Five patients were female and 2 male (median age, 61 years). Each neoplasm was composed of undifferentiated, small round cells in a predominantly solid pattern. Initially, ordered immunostains corresponded with early diagnostic impressions of a hematologic malignancy or neuroendocrine carcinoma. CD56 was positive in 5 of 5 tumors and synaptophysin in 1 of 6. Given the virtual absence of other lymphoid or epithelial markers, muscle immunostains were performed and these were positive. Definitive alveolar rhabdomyosarcoma diagnoses were confirmed genetically. This study illustrates the diagnosis of head/neck alveolar rhabdomyosarcoma in older adults is complicated by its rarity, lack of an alveolar pattern, and a potentially misleading immunoprofile (CD56 and synaptophysin immunoreactivity) if myogenic markers are not used. Both PAX3- and PAX7-FOXO1 alveolar rhabdomyosarcomas were identified in these patients. In children, PAX7-FOXO1 alveolar rhabdomyosarcoma is associated with a significantly longer event-free survival. In contrast, adult alveolar rhabdomyosarcoma behaves more aggressively with a worse overall survival than pediatric alveolar rhabdomyosarcoma. Further follow-up and additional cases are required to assess the prognostic relevance of these fusion transcripts in the context of advanced age.

Primary cutaneous adenoid cystic carcinoma

Primary cutaneous adenoid cystic carcinoma is a rare, slow-growing malignancy first described by Boggio in 1975. This tumor characteristically consists of basophilic cells with a distinct adenoid or cribriform pattern in the mid to deep reticular dermis. Modified myoepithelial cells with prominent basement membrane material often surround true lumina. Definitive diagnosis relies on the characteristic histologic features and the exclusion of metastatic disease. We describe two patients who presented with painful papules of the scalp and were successfully treated with wide local excision.

Utility of high molecular weight cytokeratins, but not p63, in the differential diagnosis of neuroendocrine and basaloid carcinomas of the head and neck

High-grade neuroendocrine carcinomas of the head and neck overlap significantly in morphology with both basaloid squamous and solid-type adenoid cystic carcinomas. High-grade neuroendocrine carcinomas have sheets of small cells with scant cytoplasm, granular chromatin, and inconspicuous nucleoli. Basaloid squamous and adenoid cystic carcinomas are aggressive variants of their respective tumor types which both have nests of basaloid tumor cells with round nuclei, little cytoplasm, and inconspicuous nucleoli. As the management and prognosis of these tumors are very different, it is important to differentiate them. We performed high molecular weight cytokeratin (CK) and p63 immunohistochemistry on 19 neuroendocrine carcinomas, 18 basaloid squamous carcinomas, and 11 solid-type adenoid cystic carcinomas. All tumors were immunostained for p63, CK 34betaE12, CK 5/6, synaptophysin, chromogranin-A, S-100, and smooth muscle actin. All basaloid squamous and adenoid cystic carcinomas were positive for CK 5/6 and 34betaE12. Only 4 and 5 of the 19 neuroendocrine carcinomas, respectively, were positive for these markers. Staining was focal in the neuroendocrine cases when positive, whereas almost all basaloid squamous and adenoid cystic carcinomas showed strong staining. Almost all tumors of each type were positive for p63, including neuroendocrine carcinomas, but with different staining patterns. Basaloid squamous carcinomas were diffusely positive, neuroendocrine carcinomas were diffusely positive, but with weak staining, and adenoid cystic carcinomas showed a distinct pattern with staining at the periphery of the cell nests only. We conclude that high molecular weight cytokeratin immunostaining is helpful in distinguishing high-grade neuroendocrine carcinomas from similar tumor types.

Clonal nature of sclerosing polycystic adenosis of salivary glands demonstrated by using the polymorphism of the human androgen receptor (HUMARA) locus as a marker

Sclerosing polycystic adenosis (SPA) is a recently described, rare lesion of the salivary glands that bears a resemblance to epithelial proliferative lesions of the breast. The true nature of the lesion is unknown, but up to now it has been generally believed to represent a pseudoneoplastic sclerosing and inflammatory process. However, local recurrence developed in about one-third of the cases. Superimposed dysplastic changes ranging from low-grade dysplasia to carcinoma in situ were described in SPA. Although no metastases-related and/or disease-related patient deaths were documented, these clinical and histopathologic features raise the possibility that SPA might represent a neoplastic lesion. Polymorphism of the human androgen receptor locus is most frequently used to assess whether the pattern of X-chromosome inactivation is random or nonrandom, the latter strongly indicating clonality. In this study, the assay was applied to tissue from 12 examples of SPA. Three cases (males) were noninformative and 3 cases (females) could not be analyzed owing to poor quality of DNA, but all the remaining 6 lesions satisfied the criteria for monoclonality. We therefore conclude that the findings in the present study are further supporting evidence that SPA is a neoplasm, and not just a reactive process.

Sclerosing polycystic adenosis of the salivary gland: a report of 16 cases

Sclerosing polycystic adenosis is a recently described, extremely rare, reactive, sclerosing, inflammatory process somewhat similar to fibrocystic changes and adenosis tumor of the breast. To date, there have been 22 cases described in the literature. Because of the infrequency of this lesion, we describe our combined experience with 16 cases, 1 of which has been previously reported. Thirteen tumors arose in the parotid gland, two involved the submandibular gland, and one arose in the buccal mucosa. There were 9 men and 7 women. Patients ranged in age from 9 to 75 years. Fourteen patients presented with a primary mass. Two were incidental findings in patients with a mixed tumor and an oncocytoma. Tumors ranged in size from 0.3 to 6 cm in greatest dimension. They are typically well circumscribed and are composed of densely sclerotic lobules with prominent cystic change. Hyperplasia of ductal and acinar elements and areas of apocrine-like metaplasia are frequent. Foci with mild ductal epithelial atypia were frequent with >50% of cases demonstrating at least focal areas of duct epithelial hyperplasia with atypia. Follow-up ranged from 1.5 to 40 years. One tumor recurred twice; no patient has developed metastases or died of disease.

Spiradenocylindrocarcinoma: a malignant hybrid tumor

BACKGROUND

Eccrine spiradenomas and cylindromas are benign, slowly growing, cutaneous adnexal neoplasms, recently hypothesized to arise from a common pluripotential cell; malignant variants are rare. We found 48 cases of malignant spiradenomas and 33 cases of malignant cylindromas reported in the English literature. Benign tumors demonstrating both spiradenomatous and cylindromatous features have been infrequently reported. Recent immunohistochemical studies of these two tumors have provided compelling evidence that these two tumors may merely represent a single tumor type with a spectrum of histological features.

CASE REPORT

We describe two cases of a malignant variant of this rare hybrid tumor occurring in a 62-year-old male and a 72-year-old female.

CONCLUSION

We propose the term 'spiradenocylindrocarcinoma' to describe malignant tumors with features of both a spiradenoma and a cylindroma. In conjunction with histological features of malignancy, p53 and Ki-67 immunohistochemical staining may provide helpful clues in determining the malignant potential of this tumor. Further studies are needed to clarify the biologic behavior of such lesions.

Low-grade salivary duct carcinoma: description of 16 cases

Low-grade salivary duct carcinoma is a rare neoplasm. We report on 16 patients, with a median age of 64 years. All but one tumor arose from the parotid gland, including one tumor that arose in an intraparotid lymph node; one arose in the submandibular gland. Tumors consist of single to multiple dominant cysts, accompanied by adjacent intraductal proliferation. Cysts are lined by small, multilayered, proliferating, bland ductal cells with finely dispersed chromatin and small nucleoli. Separate, smaller ductal structures are variably filled by proliferating ductal epithelium with cribriform, micropapillary, and solid areas. The overall appearance is very similar to breast atypical ductal hyperplasia and low-grade ductal carcinoma in situ. Foci of definitive stromal invasion were seen in four tumors. Two tumors demonstrated transition from low- to intermediate- or high-grade cytology, with scattered mitotic figures and focal necrosis. S-100 revealed diffuse strong expression in all 9 cases studied. Myoepithelial markers (calponin) highlighted supportive myoepithelial cells rimming the cystic spaces, confirming the intraductal nature of most, or all, of six tumors studied. Nine tumors studied for Her2-neu antigen were uniformly negative. Follow-up was obtained on 13 of our 16 patients. All patients were disease-free after surgery 6 to 132 months (median 30 months). Low-grade salivary duct carcinoma is a low-grade neoplasm with an excellent prognosis; it may be treated by conservative but complete resection. Its resemblance to atypical breast ductal hyperplasia, or micropapillary/cribriform intraductal carcinoma, distinguishes it from high-grade salivary duct carcinoma, papillocystic acinic cell carcinoma, and cystadenocarcinoma.

Hyalinizing clear cell carcinoma of salivary gland: an aggressive variant

Although hyalinizing clear cell carcinoma (HCCC) had been previously illustrated by several authors, it was not until 1994 that this tumour was characterized by Milchgrub et al. [Am J Surg Pathol (1994),18,74] and separated from the heterogeneous group of clear cell carcinomas described in the literature. HCCC is a distinctive infiltrative low-grade, monomorphic, glycogen-rich clear cell carcinoma with prominent stromal hyalinization occurring most often in the minor salivary glands of adult women. A case of hyalinizing clear cell carcinoma arising in the tongue of an adult female is described with special reference to the presence of minor foci of mitotic activity, necrosis and anaplasia in this otherwise typical low-grade carcinoma. Widespread metastases and death within a year of initial presentation in this case suggests that there may be a subset of this indolent tumour in which these features are associated with a poor prognosis.

Fine needle aspiration of parathyroid lesions

OBJECTIVE

To assess the cytologic features of parathyroid lesions and to determine if it is possible to differentiate between parathyroid hyperplasia (PH) and parathyroid adenoma (PA) based on fine needle aspiration (FNA).

STUDY DESIGN

FNAs of 14 parathyroid lesions were performed during intraoperative consultation. Alcohol-fixed, Papanicolaou-stained smears and air-dried Diff-Quik-stained smears were prepared in each case. Cytologic features were evaluated.

RESULTS

All cases, PA and PH, showed numerous bare nuclei in the background. Ninety percent of PA contained microfollicular groups in addition to sheets and syncytia, while PH was arranged primarily in sheets and syncytia without microfollicles. Nuclear pleomorphism was seen in 33% of PA and absent from PH.

CONCLUSION

Careful evaluation of cytologic features might help to differentiate between PA and PH on FNA.

Sclerosing polycystic adenosis of the salivary gland: a lesion that may be associated with dysplasia and carcinoma in situ

Sclerosing polycystic adenosis is a recently described, extremely rare, reactive sclerosing inflammatory process somewhat similar to adenosis tumor of the breast. To date, 31 cases have been described in the literature. Twenty-seven tumors involved the parotid gland, two involved the submandibular gland, and two arose within the oral cavity in minor salivary gland sites. Patients ranged in age from 9 to 80 years, with an approximate 2.5:1 female-to-male incidence. Primary tumors range in size from 1 to 7 cm in greatest dimension, are typically unencapsulated, and are composed of densely sclerotic lobules with prominent cystic change. Hyperplasia of ductal and acinar elements and areas of apocrine-like metaplasia are typical. Foci with dysplasia of ductal epithelium ranging from mild dysplasia to occasional cases with carcinoma in situ are moderately frequent. Invasive carcinoma has not been reported in these patients. Tumors in 5 (29%) of the 16 patients with follow-up have recurred. To date, no patients have developed metastases or have died from disease.

Case-control study evaluating the homogeneity and heterogeneity of risk factors between sinonasal and nasopharyngeal cancers

Sinonasal cancer and nasopharyngeal cancer may share some risk factors because both are located within the upper aerodigestive tract. They may also have different etiological profiles because of anatomic or pathologic differences. However, the similarities and differences in risk factors have rarely been studied within the same population. We assessed the risk factor profiles of sinonasal and nasopharyngeal cancers, using data from a case-control study. The 2 case groups consisted of men aged 31-59 and diagnosed pathologically with sinonasal cancer (n=70) and nasopharyngeal cancer (n=113), respectively. Controls were men without these cancers and selected from the same areas (n=1910). Logistic regression analysis showed that smoking was a risk factor for both sinonasal [odds ratio (OR)=2.5, 95% confidence interval (CI) 1.1-5.4] and nasopharyngeal cancer (OR=1.8, 95%CI 1.1-3.0). However, ever use of barbiturates without a prescription (OR=4.9, 95%CI 1.7-13.8), working with or around cutting oils on a job (OR=1.9, 95%CI 1.1-3.1) and ever having had sinus infections (OR=2.3, 95%CI 1.1-4.6) were associated with nasopharyngeal cancer only. Having received blood products other than a transfusion (OR=9.1, 95%CI 2.2-37.4) and exposure to a pesticide containing 2,4,5-T (OR=5.9, 95%CI 1.5-23.7) were related to sinonasal cancer only. When data analyses were confined to squamous cell type, smoking and exposure to chlorophenols were related to squamous cell tumors at both sites. However, use of barbiturates and sinus problems other than infection only increased the risk of nasopharyngeal carcinoma. Our study suggests that except for smoking and chlorophenol exposure, which are associated with both sites, the risk factor profiles may differ between sinonasal and nasopharyngeal cancers.

Mucoepidermoid carcinoma: a clinicopathologic study of 80 patients with special reference to histological grading

We sought to review our experience with salivary mucoepidermoid carcinoma (MEC) over two decades to confirm the validity and reproducibility of histologic grading and to investigate MIB-1 index as a prognosticator. Diagnosis was confirmed on 80 cases, and chart review or patient contact was achieved for 48 patients, with follow-up from 5 to 240 months (median 36 months). Immunohistochemistry with citrate antigen retrieval for MIB-1 was performed on a subset of cases. Kaplan-Meier survival curves were generated for each stage, site, and grade according to our proposed grading system. To address the issue of grading reproducibility, 20 slides were circulated among five observers, without prior discussion; slides were categorized as low-, intermediate-, or high-grade according to one's "own" criteria, and then according to the AFIP criteria proposed by Goode et al.10 Weighted kappa (kappa) estimates were obtained to describe the extent of agreement between pairs of rating. The Wilcoxon signed rank test or the Friedman test as appropriate tested variation across ratings. There was no gender predominance and a wide age range (15-86 years, median 49 years). The two most common sites were parotid and palate. All grade 1 MECs presented as Stage I tumors, and no failures were seen for this category. The local disease failure rates at 75 months for grades 2 and 3 MEC were 30% and 70%, respectively. Tumor grade, stage, and negative margin status all correlated with disease-free survival (DFS) (p = 0.0091, 0.0002, and 0.048, respectively). The MIB index was not found to be predictive of grade. Regarding the reproducibility of grading, the interobserver variation for pathologists using their "own" grading, as expressed by the kappa value, ranged from good agreement (kappa = 0.79) to poor (kappa = 0.27) (average kappa = 0.49). A somewhat better interobserver reproducibility was achieved when the pathologists utilized the standardized AFIP criteria (average kappa = 0.61, range 0.38-0.77). This greater agreement was also reflected in the Friedman test (statistical testing of intraobserver equality), which indicated significant differences in using one's own grading systems (p = 0.0001) but not in applying the AFIP "standardized" grading (p = 0.33). When one's own grading was compared with the AFIP grading, there were 100 pairs of grading "events," with 46 disagreements/100 pairs. For 98% of disagreements, the AFIP grading "downgraded" tumors. This led us to reanalyze a subset of 31 patients for DFS versus grade, for our grading schema compared with the AFIP grading. Although statistical significance was not achieved for this subset, the log rank value revealed a trend for our grading (p = 0.0993) compared with the Goode schema (p = 0.2493). This clinicopathologic analysis confirms the predictive value of tumor staging and three-tiered histologic grading. Our grading exercise confirms that there is significant grading disparity for MEC, even among experienced ENT/oral pathologists. The improved reproducibility obtained when the weighted AFIP criteria were used speaks to the need for an accepted and easily reproducible system. However, these proposed criteria have a tendency to downgrade MEC. Therefore, the addition of other criteria (such as vascular invasion, pattern of tumor infiltration [i.e., small islands and individual cells vs cohesive islands]) is necessary. We propose a modified grading schema, which enhances predictability and provides much needed reproducibility.

Malignant solitary fibrous tumor of the pleura with liposarcomatous differentiation

Pleural solitary fibrous tumors (SFTs) are uncommon tumors. Although these tumors have been well characterized, malignant pleural SFTs with liposarcomatous differentiation have not been reported. We report an unusual malignant pleural SFT intermixed with foci of well-differentiated liposarcoma. The patient was a 66-year-old, white man with a large, solid right pleural mass that measured 13.5 x 10.3 x 8.5 cm. The tumor was composed of spindle-shaped and plump cells embedded in dense collagenous stroma. The tumor cells were arranged in interlacing fascicles or in a patternless pattern. Marked nuclear atypia, a high mitotic rate (21 mitoses per 10 high-power fields), and areas of prominent necrosis were evident. In addition, numerous adipocytes mixed with typical lipoblasts were seen scattered throughout portions of the tumor. Immunohistochemistry revealed the tumor cells were strongly positive for CD34 and vimentin and negative for cytokeratin, desmin, smooth muscle actin (IA4), and S100. To the best of our knowledge, this case represents the first example of a malignant SFT with liposarcomatous differentiation.

Intraosseous salivary tissue: jawbone examples of choristomas, hamartomas, embryonic rests, and inflammatory entrapment: another histogenetic source for intraosseous adenocarcinoma

PROBLEM

Hundreds of primary salivary neoplasms have been found to be completely enclosed within the marrow spaces of the maxilla and mandible, yet nonneoplastic salivary tissue has never been convincingly identified within marrow, either separately or adjacent to such neoplasms. This situation has forced the acceptance of an inherently awkward odontogenic origin for all intramedullary salivary carcinomas and adenomas.

OBJECTIVE

The purpose of this study was to microscopically evaluate a large number of maxillofacial marrow samples for the presence of intramedullary salivary tissue.

STUDY DESIGN

We microscopically reviewed 5034 maxillofacial bone samples from the Latvala Inflammatory Bone Registry for evidence of heterotopic salivary inclusions within the marrow tissues. Contributing surgeons were contacted for each identified case of intraosseous salivary tissue to assure that all submitted tissue was removed from within the marrow spaces rather than from overlying soft tissue.

RESULTS

Thirteen of 5034 marrow samples (0.3%) contained heterotopic acinic hamartomas, salivary choristomas, embryonic salivary rests, or entrapped surface glands. Four additional hamartomas of the condyle are described. We report also the chance finding of incipient odontogenic epithelial neoplasms (n = 6) and odontogenic epithelial rests (n = 84) within the fatty marrow and outside the periodontal ligament spaces, confirming that not all odontogenic neoplasms are necessarily of periodontal ligament origin.

CONCLUSION

The frequency rate for salivary choristomas, hamartomas, embryonic rests, and displaced surface glands within alveolar bone is no less than 2.6 of 1000 biopsied marrow samples. This provides an additional and quite logical histogenetic explanation for the presence of intraosseous salivary neoplasms.

Skeletal muscle in routine tonsillectomy specimens: a common finding

Over the past 10 years, 1 of the authors (D.G.) has been consulted about several medical legal cases involving complications allegedly related to excessive surgery as documented by finding skeletal muscle in tonsillectomy specimens. A review of the literature showed little information about the incidence of skeletal muscle in routine tonsillectomy specimens; therefore, this study was undertaken. Thirty sequential tonsillectomy specimens from patients with histories of hyperplastic tonsils (10 males, 20 females; ages 5, 17 to 39; mean age, 24.3 years) were processed routinely (1 section/tonsil), and evaluated on a retrospective basis using routine light microscopy (group 1). In addition, 20 sequential tonsillectomy specimens were processed in a prospective fashion, excluding sleep apnea specimens (5 males, 15 females; ages 12 to 59 years; mean age, 28.9 years) (group 2). All specimens in the first group had lymphoid hyperplasia; 25 of the 30 (83%) had skeletal muscle in soft tissue adjacent to the lymphoid elements, 20 (67%) had seromucinous glands, and in 1 there was a focus of cartilage. In group 2, 18 had lymphoid hyperplasia and 2 contained carcinomas; 19 of 20 contained skeletal muscle ranging from a single fiber to abundant, multifocal areas with muscle, 16 (80%) had seromucinous glands, and 4 contained areas with cartilage. Additional tissue from the specimen without muscle and the tonsil with a single fiber was processed, and abundant skeletal muscle was identified in each. One may conclude that skeletal muscle is very frequently found in routine tonsillectomy specimens and, by itself, is not an indication of inappropriate surgical technique.

Occupational exposure to chlorophenol and the risk of nasal and nasopharyngeal cancers among U.S. men aged 30 to 60

BACKGROUND

Elevated rates of nasal and nasopharyngeal cancers have been associated with wood-related occupational exposures, including chlorophenols, formaldehyde, and wood dust.

METHODS

Occupational information was obtained from 43 nasal carcinoma cases, 92 nasopharyngeal carcinoma cases, and 1909 controls, by interview. Exact conditional logistic regression was used to evaluate the association of these cancers with chlorophenol exposure, estimated from a review of verbatim responses.

RESULTS

Both nasal and nasopharyngeal cancers were significantly associated with estimated duration of chlorophenol exposure. For nasopharyngeal cancer, elevated risk was observed among those who held jobs assigned medium or high intensity chlorophenol exposure (n(exposed)=18, OR=1.94, 95% CI=1.03-3.50) and among those with 10+ years in jobs assigned high intensity with high certainty (n(exposed)=3, OR=9.07, 95% CI=1.41-42. 9). Controlling for estimated formaldehyde and wood dust exposure did not alter these findings, as much of the estimated chlorophenol exposure was among machinists.

CONCLUSIONS

These findings support the hypothesis that occupational exposure to chlorophenol is a risk factor for nasal and nasopharyngeal cancer, although the role of machining-related exposures warrants further assessment.

Sarcomatoid salivary duct carcinoma of the parotid gland

Salivary duct carcinoma (SDC) is a high-grade neoplasm known to histologically resemble high-grade ductal carcinoma in situ of the breast. We describe 3 cases of sarcomatoid salivary duct carcinoma, a heretofore unreported variant of SDC. Each case was a composite of SDC and sarcomatoid carcinoma and histologically similar to reported cases arising in the breast. The clinicopathologic features, including immunohistochemistry, of 3 cases were investigated. In the 3 men, ages 56, 68, and 70 years, the resected parotid tumors measured 1.5, 3.5, and 1.5 cm, respectively. Only the 3.5-cm tumor extended beyond the parotid gland into soft tissue. This patient died at 3 years with pulmonary metastases. The other patients were free of disease at 6 and 12 months. Histologically, each case was a composite of usual-type SDC and sarcomatoid carcinoma. SDC showed typical cribriform architecture, whereas anaplastic, spindled cells constituted the sarcomatoid areas. Immunohistochemically, epithelial elements stained as follows: cytokeratin (AE1/AE3 & CAM 5.2) positive in 3 of 3 cases, EMA positive in 3 of 3 cases, vimentin negative in 3 of 3 cases, desmin negative in 3 of 3 cases, c-erbB-2 positive in 1 of 2 cases. Sarcomatoid elements stained as follows: AE1/AE3 negative in 3 of 3 cases, CAM 5.2 rare positive cell in 1 of 3 cases, EMA focally positive in 3 of 3 cases, vimentin positive in 3 of 3 cases, desmin negative in 3 of 3 cases, c-erbB-2 negative in 2 of 2 cases. Electron microscopy, performed in one case, showed scattered junctional complexes congruent with epithelial differentiation. Immunohistochemical results, EMA and CAM 5.2 positivity, and ultrastructural findings supported our belief that these unique biphasic tumors represented SDC with sarcomatoid carcinoma. We conclude an element of sarcomatoid carcinoma rarely may arise in association with SDC, and it is erroneous to diagnose such tumors as "carcinosarcoma."

Frequent loss of heterozygosity at chromosome 3p14.2-3p21 in human pancreatic islet cell tumours

OBJECTIVE

Pancreatic islet betacell tumours occur either sporadically or as part of inherited neoplastic syndromes, most commonly multiple endocrine neoplasia (MEN) type 1. Recently, a transgenic mouse model has been established in which the expression of the SV40 large T antigen was targeted to betacells by the rat insulin promoter, leading to the development of multiple pancreatic betacell tumours. In the advanced stages of tumour evolution, these tumours exhibited a high prevalence of loss of heterozygosity (LOH) on mouse chromosomes 9 and 16, at regions syntenic with regions 3q, 3p21, 6q12, 15q24 and 22q of the human genome.

DESIGN

Loss of heterozygosity in human islet cell tumours was analysed in a PCR based approach at regions of the human genome syntenic with the mouse loci linked to pancreatic betacell tumours as well as the MEN1 gene on chromosome 11q13. These included 35 microsatellite markers in the human chromosomal regions 3q, 3p21, 6q12, 11q13, 15q24 and 22q.

PATIENTS

21 patients diagnosed with insulinoma were analysed. Histologically, 16 tumours were benign, while 5 were malignant insulinomas.

RESULTS

Thirteen of 21 (62%) tumours were found to have loss of genetic material on chromosome 3. The shortest region of overlap implicated a deletion at 3p14.2-3p21 region, corresponding to the marker D3S1295. We did not detect a substantial frequency of LOH in the other syntenic regions, except for the region of MEN 1 gene on 11q13 found to be deleted in 6 (29%) cases, including 3 of 4 tumours from MEN 1 families. Deletions of 3p14. 2-3p21 were observed in 8 of 15 (53%) benign tumours, and in 5 of 6 (83%) malignant neoplasms.

CONCLUSIONS

These results indicate the high frequency of 3p14.2-3p21 deletions in human pancreatic betacell neoplasms. These finding suggest the presence of a tumour suppressor gene in this region, that may be important in the microevolution of these tumours towards malignancy.

Exophytic and papillary squamous cell carcinomas of the larynx: A clinicopathologic series of 104 cases

Exophytic and papillary squamous cell carcinomas (SCCs) are uncommon variants of SCC of the upper aerodigestive tract mucosa. The histomorphologic distinction between these variants has not been previously attempted or correlated with prognostic outcome. One hundred four cases of exophytic and papillary SCCs of the larynx were identified in the files of the Armed Forces Institute of Pathology from 1971 to 1991. The patients included 25 women and 79 men, aged 27 to 89 years (average 60.7 years). Patients had hoarseness at presentation, and many patients were using tobacco (n = 87) and/or alcohol (n = 49). Tumors measured up to 6 cm in greatest dimension. The larger tumors were associated with vocal cord impairment (n = 39). Histologically, the SCCs were divided into 2 growth patterns: papillary-frond (n = 12) or broad-based, exophytic (n = 92). Patients were treated with excisional biopsy, vocal cord stripping, and/or laryngectomy, in conjunction with radiation therapy (n = 70). Eighty-seven patients had no evidence of disease at last follow-up (average follow-up 8.6 years). Seventeen patients with an exophytic pattern died with disease (10 disseminated disease; 7 local disease). No patients with papillary patterns died of disease, although there had been 4 recurrences. In conclusion, patients with papillary and exophytic SCCs have a better prognosis than those with conventional SCCs, and the prognosis for those with papillary SCCs is even better.

Basal cell adenocarcinoma of the salivary gland: an ultrastructural and immunohistochemical study

OBJECTIVE

The purpose of this study was to examine the ultrastructural and immunohistochemical characteristics of basal cell adenocarcinoma.

STUDY DESIGN

Three cases of basal cell adenocarcinoma of the salivary glands were studied by means of light microscopy, electron microscopy, and immunohistochemistry.

RESULTS

Some of the architectural tumor patterns encountered were solid, some were trabecular, and some were mixed. Ultrastructurally, solid areas were composed of nonluminal cells, some of which contained tonofilaments and well-formed desmosomes; tubulo-trabecular areas differentiated into both luminal and nonluminal cells. Both growth patterns were associated with the formation of excess basal lamina, marginally and between nonluminal cells. Myofilaments were infrequent in nonluminal cells of solid or trabecular areas. Cytokeratin (AE1/AE3) stained all 3 tumors, more peripherally in the solid pattern and usually centrally in the trabecular areas; vimentin stained all 3 tumors diffusely; smooth muscle actin (IA4) stained all 3 tumors but was mainly confined to peripheral tumor cells in both the solid and the trabecular growth patterns; epithelial membrane antigen and carcinoembryonic antigen stained 1 of the 3 tumors, predominantly in the luminal cells; p53 oncoprotein was focally positive in 2 of the 3 tumors; Ki-67 stained less than 5% of the tumor cells in all cases; and c-erb-B2 was uniformly negative in all cases. Staining patterns of cytokeratin and actin varied with the architecture of the tumor.

CONCLUSIONS

Neither ultrastructural characteristics nor immunohistochemistry findings appear to distinguish basal cell adenocarcinoma from basal cell adenoma.

Pathomorphology of thyroid gland lesions associated with radiation exposure: the Chernobyl experience and review of the literature

The common sources of ionizing radiation exposure to the thyroid gland in humans are accidental environmental exposure and medical, therapeutic, or diagnostic irradiation. Radiation often induces notable histologic changes in the thyroid tissue and is a well-established risk factor for benign and malignant thyroid tumors. In this paper, we review the acute and chronic histologic changes in the thyroid gland subjected to irradiation, and characterize benign thyroid nodules and malignant tumors arising after exposure, with particular emphasis on thyroid lesions in the population exposed to ionizing radiation as a result of the Chernobyl nuclear accident.