[Clinicopathological features of olfactory carcinoma]

Objective: To investigate the clinicopathological features and differential diagnosis of olfactory carcinoma (OC). Methods: Twenty-one cases of sinonasal tumors, including those initially diagnosed as olfactory neuroblastoma (ONB) and those with uncertain diagnosis, were collected from the Department of Pathology, the First Affiliated Hospital of University of Science and Technology of China (Anhui Provincial Hospital) from January 2016 to August 2022, among which 3 cases were reclassified as OC. The clinicopathological features were investigated, and the remaining 18 cases were used as control. Results: Of the three OC patients, 2 were male and 1 was female, with an average age of 57 years ranging from 35 to 74 years. Microscopically, the tumor cells were arranged in solid, nested or lobulated patterns with occasional palisading around the solid nests. The stroma was highly vascular with focal neurofibrillary areas. There were prominent rosettes or pseudorosettes formation. The tumor cells were mainly ovoid to spindly with scant to moderate amount of cytoplasm, one or several small nucleoli, and fine chromatin content. Brisk mitotic figures were seen. In all 3 cases of OC, there were scanty atypical glands and some were ciliated. Immunohistochemically, at least one epithelial marker and neuroendocrine marker were diffusely expressed in the tumor. Some of the tumor cells were positive for p40 and p63, and the sustentacular cells showed the expression of S-100 protein. All cases tested were negative for NUT, CD99 and desmin, with intact expression of SMARCA4 (BRG1) and SMARCB1 (INI-1). Ki-67 proliferation index varied from 20% to 80%. Follow-up after 16-18 months showed no mortality with tumor recurrence from 1 patient after 16 months. Conclusion: OC is a rare sinonasal tumor with neuroepithelial differentiation, its histomorphology is diverse, and the combination of immunohistochemical markers is essential for appropriate diagnosis.

DEK-AFF2 Carcinoma of the Sinonasal Region and Skull Base: Detailed Clinicopathologic Characterization of a Distinctive Entity

A novel DEK-AFF2 fusion was recently reported in 4 nonkeratinizing squamous cell carcinomas of the sinonasal region and skull base, including 1 with exceptional response to immunotherapy, but it is not yet clear if this rearrangement defines a unique clinicopathologic category or represents a rare event. This study aims to characterize a larger cohort of carcinomas with DEK-AFF2 fusions to assess whether they truly constitute a distinctive entity. Among 27 sinonasal and skull base nonkeratinizing squamous cell carcinoma that were negative for human papillomavirus and Epstein-Barr virus, RNA sequencing identified DEK-AFF2 fusions in 13 cases (48%). Nine were centered in the nasal cavity, 2 in the middle ear/temporal bone, 1 in the nasopharynx, and 1 in the orbit. These tumors displayed recurrent histologic features including (1) complex endophytic and exophytic, frequently papilloma-like growth, (2) transitional epithelium with eosinophilic to amphophilic cytoplasm, (3) absent or minimal keratinization with occasional compact keratin pearls, (4) monotonous nuclei, and (5) prominent tumor-infiltrating neutrophils or stromal lymphocytes. This appearance not only overlaps with high-grade basaloid sinonasal carcinomas but also with benign papillomas and tumors reported as low-grade papillary Schneiderian carcinoma. However, DEK-AFF2 carcinomas showed frequent local recurrence, cervical lymph node metastases, and distant metastasis with 2 deaths from disease, confirming they are aggressive malignancies despite relatively bland histology. Overall, the distinctive molecular, histologic, and clinical features of DEK-AFF2 carcinomas suggest they represent a unique entity in the sinonasal region. This tumor merits increased pathologic recognition to better understand its prognostic and therapeutic implications.

Metastatic SMARCB1 (INI-1)-Deficient Sinonasal Carcinoma Diagnosed by Endobronchial Ultrasound-Guided Fine-Needle Aspiration (EBUS-FNA): A Potential Diagnostic Pitfall and Review of the Literature

SMARCB1 (INI-1)-deficient sinonasal carcinoma is a rare entity within the subgroup of poorly differentiated sinonasal tract carcinomas. As there are only two papers describing the cytologic features of this entity, herein we describe the unique cytomorphologic features of a pulmonary metastasis of this tumor and include the differential diagnosis based on tumor location. The patient was a 53-year-old male who initially presented with sinus congestion and vision changes including left-eye proptosis and diplopia. The initial biopsy of the ethmoid-centered sinonasal mass was non-keratinizing squamous cell carcinoma based on strong immunoreactivity with p40 and absence of immunoreactivity for chromogranin, synaptophysin, p16, and EBER. However, the final diagnosis of the surgical resection was amended to SMARCB1 (INI-1)-deficient sinonasal carcinoma after additional immunohistochemical stains were performed. Post-primary resection, follow-up computed tomography imaging revealed significant interval progression of a solitary, initially indeterminate 1-cm lung nodule in the left upper lobe. Endobronchial ultrasound-guided fine-needle aspiration with concomitant core-needle biopsy was performed. Rapid on site evaluation of cytologic smears revealed a hypercellular specimen consisting of sheets of epithelioid cells with very scant to absent cytoplasm, ill-defined cell borders, enlarged fragile nuclei, and areas of nuclear molding. Mitotic figures were present. Other areas showed tumor cells with spindled to elongated nuclei and scant to ill-defined wispy cytoplasm. Both cytology cell block and core-needle biopsy histopathologic material showed the tumor cells to be negative for INI-1 nuclear staining as well as CK5/6, CAM5.2, p40, p63, CK7, AE1/3, and TTF-1. SMARCB1 (INI-1)-deficient sinonasal carcinoma can have a spectrum of morphologies and may mimic "small-round-blue-cell" and spindle-cell tumors on cytology preparations. Given the pulmonary location of the aspirate, familiarity with the cytomorphologic spectrum of SMARCB1 (INI-1)-deficient sinonasal carcinoma, inclusion of this entity within the differential diagnosis, and performance of immunohistochemistry will aid in arriving at the correct diagnosis.

ETV6 Gene Rearrangements Characterize a Morphologically Distinct Subset of Sinonasal Low-grade Non-intestinal-type Adenocarcinoma: A Novel Translocation-associated Carcinoma Restricted to the Sinonasal Tract

Low-grade sinonasal adenocarcinomas (low-grade SNACs) of the sinonasal tract comprise a poorly characterized and histologically heterogeneous group of tumors. We describe three cases of a histologically distinct variant of low-grade SNAC characterized by ETV6 gene rearrangements. The patients included 2 women (aged 32 and 88 y) and a man (aged 75 y); all were initially treated with surgery alone. Follow-up ranged from 9 to 170 months with one patient having 2 local recurrences and none experiencing distant or regional metastases. Tumors were composed of cytologically bland columnar and cuboidal eosinophilic tumor cells with basally located nuclei arranged in tubular and tubulotrabecular patterns. Immunohistochemically, CK7, DOG1, GCDFP-15, and SOX10 were positive in all cases, and vimentin was positive in 2 cases. Scattered single cells or small groups of tumor cells were S-100 positive. Only one case had weak, focal expression of GATA3, and mammaglobin was consistently negative. Two cases had ETV6-NTRK3 gene fusions, whereas ETV6 had an unknown fusion partner gene in one case. The highly similar morphology, immunohistochemical profile, and genetics of the presented cases are suggestive of a specific disease. Although translocation-associated adenocarcinomas in the sinonasal tract have previously been described exclusively as salivary-type carcinomas, we present the first type of carcinoma characterized by recurrent genetic rearrangements and distinct phenotype occurring exclusively in the sinonasal tract with no known major salivary gland counterpart. We provisionally designate this tumor ETV6-rearranged low-grade SNAC. Identification of additional cases is necessary to fully appreciate the morphologic and biological spectrum of this disease.

Alveolar Rhabdomyosarcoma of the Paranasal Sinuses in a 57-Year-Old Woman With 1:16 Translocation

Alveolar rhabdomyosarcoma is an uncommon tumor. It is araremalignancy in adults and rarely occurs in paranasal sinuses in thoseaged older than 50 years. This report describes a locally invasi and destructive alveolar rhabdomyosarcoma arising in the ethmoidsinus of a 57-year-old woman. The small round blue cell tumors are positive for myogenin by immunohistochemistry and have a karyotype of 45, XX, -5, -13, der(16)t(1;1) (q21;q13) by cytogenetic analysis. Fluorescence in situ hybridization demonstrated a complex translocation with break apart of the FKHR region, which supports a diagnosis of alveolar rhabdomyosarcoma. This report characterizes this tumor through microscopic and cyto-genetic analysis and emphasizes the importance of considering rhabdomyosarcoma in the differential diagnosis of small round cell tumors of the head and neck region in the middle-aged adults.

Alveolar rhabdomyosarcoma of nasopharynx and paranasal sinuses with metastasis to breast in a middle-aged woman: a case report and literature review

Alveolar rhabdomyosarcoma (ARMS) is a common soft tissue tumor in children which can rarely metastasize to the breast in adults. Here we report the rare case of a 42-year-old Asian woman, who was diagnosed with ARMS of the nasopharynx and paranasal sinuses, and got a complete remission (CR) after surgery and chemoradiotherapy. Then the patient relapsed in the unilateral breast seventeen months later. Histology and immunohistochemistry of the primary sites and the breast lesions, combined with FISH, have been performed to confirm the diagnosis of metastatic alveolar rhabdomyosarcoma. With a rational therapeutic regimen of surgery, chemotherapy and radiotherapy, the patient has got a complete remission again.

Sinonasal clear cell adenocarcinoma: a case report

BACKGROUND

Nonsalivary adenocarcinomas are the most interesting tumors found in the sinonasal area. They are rare tumors arising from surface epithelium. The clear cell type of this tumor is even more rare. We present cytologic findings of clear cell sinonasal adenocarcinoma and related pitfalls.

CASE

A 52-year-old woman presented with a left-cheek facial mass of 3-4 years' duration, with progressive enlargement, nasal discharge and discoloration of the lateral side of her left eye. Computed tomography was performed, revealing an expansile mass involving the nasal cavity, left maxillary sinus, ethmoid sinus with extension to sphenoid sinus, left side of oral cavity and left orbit. Fine needle aspiration performed through the upper buccogingival canine fossa showed clusters of epithelial cells with clear cytoplasm, round nuclei, inconspicuous nucleoli and slight pleomorphism. Some normal ciliated columnar epithelial cells are identified in the vicinity of neoplastic cells. The mass was reported to be a clear cell neoplasm, and excision of the whole mass was performed.

CONCLUSION

Cytologic findings of this rare tumor overlap with those of salivary gland-type tumors with clear cell change and should be added to the list of head and neck tumors with clear cell change.

Myofibroblastic sarcoma of the nasal cavity and paranasal sinus: a clinicopathologic study of 6 cases and review of the literature

OBJECTIVE

We describe the clinicopathologic features of 6 cases of myofibroblastic sarcoma (MS) occurring in the nasal cavity and paranasal sinus.

STUDY DESIGN

The paraffin-embedded tissues of 6 cases of MS were stained immunohistochemically and examined by electron microscopy.

RESULTS

Clinically, a painless enlarging mass was the most common symptom, followed by the nasal obstruction, epistaxis, copious rhinorrhea, and proptosis. Histologically, the tumors showed a diffusely infiltrative growth pattern and consisted mainly of spindle cells with abundant eosinophilic cytoplasm. The hypocellular myxoid areas and the hypercellular fibrous areas were identified. Immunohistochemically, all 6 tumors were positive for vimentin, alpha-smooth muscle actin, calponin, and fibronectin. Ultrastructural examination in 3 cases showed characteristic features of myofibroblast. Follow-up in 6 patients revealed high local recurrence rate (6 out of 6).

CONCLUSION

Myofibroblastic sarcoma of the nasal cavity and paranasal sinus exhibit diverse histologic appearances and a strong aggressive behavior.

Signet-Ring Cell Adenocarcinoma of Sinonasal Tract: An Immunohistochemical Study of the Mucins Profile

Context.—Adenocarcinomas of the sinonasal tract are classified into 4 categories: salivary-type, intestinal-type, nonintestinal-type, and metastatic. Signet-ring cell carcinoma is the rarest form of intestinal-type adenocarcinoma. Only isolated cases have been reported in the literature.

Objective.—To evaluate clinical attributes, morphology, and immunohistochemistry in signet-ring cell carcinoma of the sinonasal tract.

Design.—Seventy-three cases of primary sinonasal adenocarcinomas were retrieved from the files. Only 5 signet-ring cell adenocarcinomas (tumors composed of more than 90% signet-ring cells) were identified. In all cases, clinical data and histologic slides were available and were reviewed. Consecutive tissue sections were immunostained with monoclonal antibodies against MUC2, MUC5AC, MUC5B, MUC6, p53 protein, and MIB-1.

Results.—Four of our 5 patients were woodworkers. They were treated by surgical excision and radiotherapy. Patient follow-up ranged from 11 to 84 months. Three patients presented an unfavorable evolution and died of metastatic spread. Microscopically, the tumors produced abundant mucin deposits, which accumulated in large extracellular pools. Tumor cells were predominantly signet-ring cells floating in the pools of mucin. The mucins profile was MUC2+, MUC5AC+, MUC5B+, and MUC6−. Eighty percent of cells were immunostained by p53 protein antibody and 60% cells with MIB-1 antibody.

Conclusions.—The mucin profile is similar to the profile described in digestive tract adenocarcinoma. It is not useful to differentiate between metastatic adenocarcinoma and primary intestinal-type sinonasal adenocarcinoma. Clinical data and immunochemistry with p53 protein and MIB-1 confirm that sinonasal signet-ring cell carcinoma is a high-grade and aggressive tumor.

Expression of p16 in sinonasal malignant melanoma

The aim of this study was to investigate the expression of p16 in relation with the histopathologic features and the clinical course in patients with sinonasal melanoma. Thirty-seven sinonasal melanomas were immunostained for p16. Seventeen tumours were investigated for loss of the 9p21 region using interphase fluorescence in situ hybridization (FISH). Twenty-seven melanomas (72.9%) showed loss of p16 expression. All cases with spindle or mixed cytology showed loss of p16, whereas this was present in 50% of epithelioid tumours (p=0.01). Loss of p16 expression was more frequently seen in melanomas with alveolar architecture (87.5%) than in tumours with diffuse architecture (68.9%) (p=0.4). There was no correlation between p16 expression and presence of lymph node or distant metastases (p=0.57 and 0.24, respectively). In addition, p16 status did not influence overall survival (p=0.2). The FISH results were in good agreement with immunohistochemistry: 11 tumours out of 17 showed deletion of the 9p21 region and 10 of these showed loss of protein expression. Loss of p16 expression is a frequent event in sinonasal melanoma and it is mainly related to deletion of 9p21 region. At variance from cutaneous melanoma, loss of p16 is not correlated with the prognosis of patients affected by sinonasal melanoma.

Psammomatoid ossifying fibromas: immunohistochemical analysis and differential diagnosis with psammomatous meningiomas of craniofacial bones

OBJECTIVE

To clarify the role of immunohistochemistry in the diagnosis of psammomatoid ossifying fibroma (PSOF), conventional cemento-ossifying fibroma (COF), and psammomatous meningioma (PM) of the craniofacial skeleton.

STUDY DESIGN

The histology and immunohistochemistry of 4 PSOFs, 6 COFs, and 7 PMs was studied. Antibodies included EMA, cytokeratins, smooth muscle actin (SMA), desmin, vimentin, CD34, CD10, S-100 protein, and glial fibrillary acidic protein (GFAP).

RESULTS

All PSOFs showed multiple round ossicles homogeneously distributed within a fibroblastic stroma. Psammomatous meningiomas had meningothelial features. All tumors, except 1 COF, were positive for EMA. All of them expressed vimentin, and none showed cytokeratins. Staining for SMA and S-100 protein was variable. CD10 was positive in all cases except 2 meningiomas. CD34 and GFAP stained only 1 case of meningioma each.

CONCLUSIONS

The diagnosis of PSOF should rest on histologic features. An incorrect diagnosis of meningioma based on the expression of EMA should be avoided.

D2-40 staining in sinonasal-type hemangiopericytoma--further evidence of distinction from conventional hemangiopericytoma and solitary fibrous tumor

D2-40 is a monoclonal antibody, which reacts with a fixative-resistant epitope of lymphatic endothelium. Sinonasal-type hemangiopericytoma (SHP) and tumors of the (conventional) hemangiopericytoma/solitary fibrous tumor family (HP/SFT) are characterized by prominent vasculature. However, data concerning D2-40 labeling of these tumors are very sparse. In the present study, we investigated D2-40 staining in tissue specimens of 17 patients with SHP (male to female ratio of 2.4:1, median age of 63 years) and compared the immunolabeling with 20 cases of HP/SFT, including three SFT cases from nasal mucosa. D2-40 was detected in vascular channels of all SHP patients examined. By contrast, all cases of HP/SFT did not reveal any vascular channel being positive for D2-40, neither in the nasal cases nor in the remaining patients. This study presented for the first time data on D2-40 labeling in a series of SHP, HP/SFT, and supports the distinction of SHP from HP/SFT.

Expression of mismatch repair proteins, beta catenin, and E cadherin in intestinal-type sinonasal adenocarcinoma

BACKGROUND

Despite their histological resemblance to colorectal adenocarcinomas, there is little information about the molecular events involved in the pathogenesis of intestinal-type sinonasal adenocarcinomas (ITACs).

AIMS

To evaluate the possible role of DNA mismatch repair (MMR) gene defects or disruptions of the E cadherin-beta catenin complex in ITAC by investigating the immunohistochemical expression of the MMR gene products, beta catenin, and E cadherin in a group of sporadic ITACs.

METHODS

Ten sporadic cases of ITAC were stained with antibodies against MLH1, MSH2, MSH3, MSH6, beta catenin, and E cadherin.

RESULTS

Nine cases showed strong nuclear expression of MLH1, whereas one case showed moderate staining. All 10 cases were strongly positive for MSH2 and MSH3. MSH6 was strong in nine cases, and moderate in one. Membranous beta catenin expression was strong in all 10 cases, and no case showed cytoplasmic or nuclear staining. E cadherin was strong in seven cases, and moderate in three cases.

CONCLUSIONS

The preserved nuclear expression of MLH1, MSH2, MSH3, and MSH6 suggests that mutations or promoter methylation of MMR genes do not play a role in the pathogenesis of ITAC. The strong membranous staining for E cadherin and beta catenin and lack of abnormal cytoplasmic or nuclear expression is in keeping with the preservation of E cadherin-beta catenin complexes and beta catenin pathways.

Expression pattern of CK7, CK20, CDX-2, and villin in intestinal-type sinonasal adenocarcinoma

BACKGROUND

Intestinal-type sinonasal adenocarcinoma (ITAC) is an uncommon neoplasm, which resembles adenocarcinoma of the gastrointestinal tract. ITAC occurs sporadically or in association with occupational exposure to hardwood dust and other agents.

AIMS

To investigate the phenotype and possible pathogenetic mechanisms of primary sinonasal and nasopharyngeal adenocarcinomas by staining for cytokeratin 7 (CK7), CK20, CDX-2, and villin.

METHODS

Twelve sporadic sinonasal and nasopharyngeal adenocarcinomas were stained with monoclonal antibodies to CK7, CK20, CDX-2, and villin. The ITACs were classified as papillary, colonic, solid, mixed, or mucinous types.

RESULTS

The diagnosis of ITAC was confirmed in 10 cases: five were colonic type and five were papillary. One was a sinonasal papillary low grade adenocarcinoma, and one a papillary nasopharyngeal adenocarcinoma, and these tumours were CK7 positive, but CK20, CDX-2, and villin negative. All ITACs were positive for CK20, CDX-2, and villin, and six were CK7 positive. One ITAC had a focus of intestinal metaplasia away from the invasive carcinoma.

CONCLUSIONS

Sinonasal ITACs have a distinctive phenotype, with all cases expressing CK20, CDX-2, and villin. Most ITACs also express CK7, although a proportion of tumours are CK7 negative. ITAC seems to be preceded by intestinal metaplasia of the respiratory mucosa, which is accompanied by a switch to an intestinal phenotype. Although ITACs are morphologically similar, differences in cytokeratin expression patterns suggest two distinct types. The expression pattern of CK7, CK20, CDX-2, and villin positive may be useful in separating these tumours from other non-ITAC adenocarcinomas of the sinonasal tract and nasopharynx.

Sinonasal tubulopapillary low-grade adenocarcinoma. Histopathological, immunohistochemical and ultrastructural features of poorly recognised entity

We present the clinicopathological, histological and immunohistochemical findings of six cases of primary tubulopapillary low-grade adenocarcinoma of the sinonasal tract with ultrastructural examination in one case. Due to its unique features, we believe that primary tubulopapillary low-grade adenocarcinoma of the sinonasal tract represents a tumour entity different from any tumours generally recognised in the sinonasal region. Our cases had an equal sex incidence, with an age range of 44-76 years. The tumour has a tendency to recur, but none of our six patients developed metastases. We feel that it is important to separate this tumour entity from other types of sinonasal adenocarcinomas that exhibit a papillary growth pattern, as they frequently pursue a much more aggressive clinical course than the tumours in this study.

Sinonasal smooth muscle cell tumors: a clinicopathologic and immunohistochemical analysis of 12 cases with emphasis on the low-grade end of the spectrum

CONTEXT

Smooth muscle tumors (SMTs) of the sinonasal tracts are very rare mesenchymal neoplasms, and the literature includes very limited data correlating histologic parameters with clinical outcome. As the behavior of SMTs is site-dependent, defining applicable criteria to distinguish among low-grade leiomyosarcoma, SMT of uncertain malignant potential (SMTUMP), and cellular leiomyoma is sometimes difficult and arbitrary.

OBJECTIVE

To correlate the clinicopathologic features of 12 well-differentiated sinonasal SMTs with MIB-1 index and clinical outcomes so as to better classify this group of tumors.

DESIGN

Twelve cases of sporadic well-differentiated SMTs arising from the sinonasal tract were retrieved from both institutions. High-grade leiomyosarcomas were excluded from this analysis. The histologic parameters assessed included circumscription, mucosal ulceration, cellularity, nuclear atypia, mitotic count, necrosis, and destruction of adjacent bony structures. The histologic classification of these tumors was based on the guidelines for SMTs of deep soft tissues, using greater than 4 mitotic figures (MF)/10 high-power fields (HPF) to separate SMTUMP from leiomyosarcoma and the presence of 1 to 4 MF/10 HPF to distinguish between leiomyoma and SMTUMP. Immunostaining of MIB-1 index was performed in 7 cases with available material.

RESULTS

This study showed a 1:1.5 male-female ratio and a mean age of 40 years (range, 20-67 years). The most frequent symptoms were nasal stuffiness and/or epistaxis. The tumors involved nasal cavity in 8 cases (67%), paranasal sinus alone in 2 cases (16.5%), and both nasal cavity and paranasal sinuses in 2 cases (16.5%). The tumors ranged in size from 0.3 to 5.5 cm (mean, 2 cm) and were classified as follows: 7 leiomyomas, 2 SMTUMPs, and 3 low-grade leiomyosarcomas. All 7 leiomyomas, 1 SMTUMP, and 1 leiomyosarcoma originated from vessel walls. Bone involvement was seen in both the SMTUMPs (1 of 2) and leiomyosarcomas (2 of 3). Focal infiltrative growth was observed only in the 3 leiomyosarcomas, 1 of which also showed microscopic coagulative tumor necrosis. Mitotic figures ranged from 0 to 10 (mean, 2.3), with absence of mitosis in all 7 leiomyomas, 1 to 4 MF/10 HPF in the 2 SMTUMPs, and more than 4 MF/10 HPF in the 3 low-grade leiomyosarcomas. The MIB-1 index was low (<or=5%) in both leiomyoma and SMTUMP groups, while the leiomyosarcomas showed a higher (>or=15%) proliferative index. All 12 patients were treated by surgical excision, and only 1 patient with leiomyosarcoma received postoperative radiation. In all 12 tumors, there was neither local recurrence nor distant metastasis after an average of 93 months of follow-up (range, 4-221 months).

CONCLUSION

Well-differentiated sinonasal SMTs are rare and occur in adults with a slight female predilection. The lesions confined within the nasal cavity were more common than those involving a single paranasal sinus or both nasal cavity and paranasal sinuses. Despite variations in location, clinical manifestation, histologic features, and MIB-1 index, these tumors appear to follow a favorable course. Complete surgical excision appears to provide adequate treatment for these patients.

Sinonasal undifferentiated carcinoma, nasopharyngeal-type undifferentiated carcinoma, and keratinizing and nonkeratinizing squamous cell carcinoma express different cytokeratin patterns

Sinonasal undifferentiated carcinoma (SNUC) is a highly aggressive malignant neoplasm that is often difficult to distinguish from other poorly differentiated carcinomas arising in the sinonasal tract. To search for a differential cytokeratin (CK) expression that could be useful for diagnostic purposes, we compared the expression of a large panel of CKs in a series of 6 SNUCs, 10 poorly differentiated squamous cell carcinomas (SCCs), 10 nonkeratinizing squamous cell carcinomas (NKSCCs), and 5 nasopharyngeal-type undifferentiated carcinomas (NPTCs). SCC, NKSCC, and NPTC frequently showed immunoreactivity for CK5/CK6, CK8, CK13, and CK19. In addition, SCC and NKSCC expressed CK14, which was not detected in NPTC, and SCC expressed CK7 (60% of cases) and CK4 (30% of cases), which were absent in NKSCC and NPTC. Three NKSCCs were associated with a Schneiderian papilloma, and the results of the immunostaining were similar in the two components, with the exception of CK4 and CK7, which were expressed by the papilloma and not by the carcinoma. In contrast to other carcinomas, SNUC was characterized by the exclusive expression of CKs of simple epithelia, such as CK8 (100% of cases), CK7 (50% of cases), and CK19 (50% of cases). Thus, there are significant differences in the pattern of CK expression between SNUC, SCC, NKSCC, and NPTC, which could be of diagnostic aid. Moreover, these findings support the hypothesis that SNUC is a separate entity from SCC and NPTC of the sinonasal tract.

Patterns of p21(waf1/cip1) expression in non-papillomatous nasal mucosa, endophytic sinonasal papillomas, and associated carcinomas

AIMS

To clarify p21(waf1/cip1) expression in sinonasal lesions.

METHODS

Archived surgical specimens from 38 patients were investigated by means of immunohistochemistry. p21(waf1/cip1) staining was evaluated in the different layers of the epithelium. In addition, human papillomavirus (HPV) infection and p53 protein overexpression were assessed and correlated with p21(waf1/cip1) expression.

RESULTS

p21(waf1/cip1) staining was negative in non-papillomatous nasal mucosa. HPV infection and p53 protein overexpression were not seen. Sixteen of 20 inverted papillomas showed p21(waf1/cip1) expression. HPV infection was found in 16 cases and p53 protein overexpression was present in 13 specimens. Expression of p21(waf1/cip1) was restricted to surface cells in five cases, but involved basal/parabasal cells in 11 specimens. Immunoreactivity for p21(waf1/cip1) in basal/parabasal cells colocalised with p53 protein overexpression. Enhanced expression rates for p21(waf1/cip1) were seen in transitional and squamous epithelium compared with columnar epithelium. p21(waf1/cip1) expression involved only surface cells in cylindrical cell papillomas. HPV infection and p53 protein overexpression were detected in all specimens. One of five squamous cell carcinomas showed p21(waf1/cip1) expression. HPV infection was seen in two cases, and all carcinomas showed p53 protein overexpression.

CONCLUSIONS

Expression of p21(waf1/cip1) is associated with terminal differentiation in surface cells in inverted papillomas and cylindrical cell papillomas, but not in non-papillomatous nasal mucosa. Overexpression of p53 protein colocalises with p21(waf1/cip1) expression in basal/parabasal cells in inverted papillomas but not in cylindrical cell papillomas. Expression of p21(waf1/cip1) in squamous cell carcinomas involves a subset of tumours with p53 protein overexpression.

Sinonasal undifferentiated carcinoma with orbital invasion: report of three cases

PURPOSE

To report three patients with sinonasal undifferentiated carcinoma (SNUC) that invaded the orbit.

METHODS

Retrospective small case series. The clinical, radiographic, and pathologic features of three patients with SNUC were reviewed.

RESULTS

Three patients with SNUC that invaded the orbit were evaluated. A biopsy was performed on the tumors, which were composed of small, hyperchromatic cells with numerous mitoses and areas of necrosis. Immunohistochemical staining was positive for cytokeratins AE1.3, epithelial membrane antigen, and neuron-specific enolase in all three tumors. Electron microscopic examination showed absence of neurosecretory granules and presence of basement membrane production. Two patients were treated with surgical resection and postoperative chemotherapy and/or radiation. One patient was treated with preoperative radiation and chemotherapy.

CONCLUSIONS

Sinonasal undifferentiated carcinoma is a high-grade tumor that arises in the nasal and paranasal sinuses and may invade the orbit. SNUC should be distinguished from other small, round, blue cell tumors, in particular, esthesioneuroblastoma.

Sinonasal NK/T-cell lymphomas in the United States

Sinonasal natural killer (NK)/T-cell lymphomas are common in Asia and areas of South and Central America but are rarely seen in the United States, where they have not been as well characterized. Fifteen cases diagnosed in Southern California were studied with respect to histologic features, immunophenotype, Epstein-Barr virus EBER in-situ hybridization (EBV EBER-ISH), and T-cell receptor gamma chain (TCR-gamma) gene rearrangement. Although ethnic background was available for only seven patients, six were of Asian or Hispanic descent with only one non-Hispanic white known. Twelve presented as sinonasal lesions, but three were limited to the oropharynx. Most cases (11 of 15) demonstrated both necrosis and an angiodestructive pattern. All cases demonstrated cytoplasmic CD3 positivity (15 of 15), and were positive for both TIA-1 and granzyme B (14 of 14). Perforin was positive in 5 of 14. CD56 was expressed in 10 of 15 and CD8 in 3 of 15. EBV EBER-ISH was positive in 14 of 14 and TCR-gamma gene rearrangement was detected in 1 of 14 cases. None (0 of 14) were positive for CD16 or CD57. Although CD16-positive histiocytes were abundant, double-label EBER-ISH/IHC failed to identify CD16 expression on EBV-positive tumor cells. Three cases with pleomorphic large cell morphology showed focal CD30 positivity, raising the differential diagnosis of anaplastic large cell lymphoma, but all were ALK-1-negative and otherwise similar to the other cases of NK/T-cell lymphoma. Sinonasal NK/T-cell lymphomas in the United States most often occur in ethnic groups from areas of reported high frequency (Asia, Central and South America), although less commonly than in endemic populations, and are otherwise similar phenotypically. A combined approach, including immunohistochemistry, EBV EBER-ISH, and TCR gene rearrangement studies, is most helpful to arrive at the correct diagnosis.

Sinonasal mucosal malignant melanoma: report of an unusual case mimicking schwannoma

Primary mucosal melanoma of the sinonasal tract is a rare malignancy that has a more aggressive clinical course than its cutaneous counterpart. The histology of these lesions varies, with differing degrees of melanin production and an epithelioid or spindle-cell growth pattern. Cutaneous melanocytic lesions may differentiate in accordance with their neural crest derivation and express morphology similar to nerve sheath tumors. We believe the following case study reports the first instance of a mucosal melanoma with a Schwannian pattern of growth, arising from the nasal cavity of a 26-year-old man.

Immunoreactivity of B-cell markers (CD79a, L26) in rare cases of extranodal cytotoxic peripheral T- (NK/T-) cell lymphomas

The monoclonal antibodies L26 (CD20) and CD79a are very useful reagents for the immunohistochemical assessment of B-cell lineage in lymphoproliferative disorders. Although very few CD20-positive peripheral T-cell lymphomas (PTL) have been reported, comprehensive analyses of CD79a reactivity in extranodal PTL and NK/T-cell lymphomas have not been performed previously. This study investigated CD79a (clone JCB117) and CD20 reactivity in 94 extranodal non-B-cell lymphomas (enteropathy-type intestinal T-cell lymphoma [n = 52], nasal NK/T-cell lymphoma [n = 11], and primary cutaneous PTL [n = 31]) and in 17 cases of nodal PTL, unspecified. In four cases (enteropathy-type intestinal T-cell lymphoma [n = 3] and nasal NK/T-cell lymphoma [n = 1]), the majority of tumor cells stained for CD79a (all CD20 negative) and one cutaneous PTL, unspecified, was CD20 positive (CD79a negative). Extensive immunophenotyping and polymerase chain reaction-based molecular analyses revealed that all five B-cell marker-positive extranodal lymphomas had a cytotoxic phenotype and did indeed represent monoclonal peripheral T-cell proliferations. To minimize the risk of misinterpretation of lymphoma cell lineage, especially in cases of extranodal, lymphoproliferative disease, we suggest the use of both CD79a and CD20 in combination with a panel of antibodies reactive to T cells, such as betaF1 and CD5, and to T cells and NK cells, such as CD3, CD2, CD56, and TIA-1.

Myxoid chondrosarcoma of the sphenoid sinus and chondromyxoid fibroma of the iliac bone: cytomorphologic findings of two distinct and uncommon myxoid lesions

Myxoid chondrosarcoma (MCS) and chondromyxoid fibroma (CMF) are two uncommon myxoid cartilaginous neoplasms with distinct cytologic features, histologic patterns, and immunoprofiles. Because these neoplasms have characteristic biological behaviors and management, their correct diagnosis is crucial to avoid debilitating and unnecessary surgical procedures. We report the imprint cytology (IC) preparation findings along with the differential diagnosis in one case each of myxoid chondrosarcoma and chondromyxoid fibroma of the splenoid sinus and iliac bone, respectively. The two great mimickers for these neoplasms, chordoma and chondrosarcoma, represent difficult diagnostic challenges, especially when MCS and CMF occur in unusual locations. IC in conjunction with the clinical and radiologic findings can provide a rapid preliminary intraoperative diagnostic interpretation which can aid in planning the immediate surgical management, as well as guide specific tissue triage for key ancillary studies such as electron microscopy and cytogenetic analyses. To the best of our knowledge, there have been no cytologic reports of MCS of the sphenoid sinus and CMF of the iliac bone.

Evaluation of Epstein-Barr virus infection in sinonasal small round cell tumors

Sinonasal undifferentiated carcinoma, olfactory neuroblastoma and malignant melanoma of the sinonasal regions are included within the category of small round cell tumors of the sinonasal region. It is difficult to diagnose these tumors on the basis of light-microscopic features alone, but, in some instances, immunohistochemical staining evaluating cytokeratin and S-100 protein, for example, is of value. On the other hand, the sinonasal region is a significant site for Epstein-Barr-virus (EBV)-related tumors, including sinonasal undifferentiated carcinoma or malignant lymphoma. Twenty-three sinonasal small round cell tumors (SSRCT) comprising 5 sinonasal undifferentiated carcinomas, 9 olfactory neuroblastomas and 9 malignant melanomas were evaluated for the presence of EBV infection by in situ hybridization for EBV-encoded RNA, combined with immunostaining for EBV-related proteins (LMP-1 and EBNA2). Furthermore, 55 SSRCT comprising 37 sinonasal undifferentiated carcinomas, 9 olfactory neuroblastomas, and 9 malignant melanomas were examined for the presence of cytokeratins (AE1/ AE3 and CAM5.2), S-100 protein and p53 protein using immunohistochemical staining. According to in situ hybridization for detecting EBV-encoded RNA 1 (EBER1), all of the sinonasal undifferentiated carcinomas showed clear, intense hybridization signals localized over the nuclei of the tumor cells and, in 3 out of 9 (33.3%) malignant melanomas, hybridization signals were also recognized. However, none of the olfactory neuroblastomas revealed hybridization signals. Immunohistochemically, 4 out of 5 (80%) sinonasal undifferentiated carcinomas were positive for LMP-1, whereas only 2 out 9 (22.2%) malignant melanomas and no olfactory neuroblastomas were positive. With regard to EBNA2, sinonasal undifferentiated carcinomas, malignant melanomas and olfactory neuroblastomas were all negative. Out of 37 sinonasal undifferentiated carcinomas 35 (94.6%) showed a diffuse positive immunoreaction for AE1/AE3, whereas neither olfactory neuroblastoma nor malignant melanoma revealed a positive reaction. All 9 malignant melanomas and 6 out of 9 olfactory neuroblastomas (75%) were positive for S-100 protein, whereas only 6 cases of sinonasal undifferentiated carcinomas (19.4%) were positive. As for p53 protein, 16 of 37 sinonasal undifferentiated carcinomas (43.2%) were positive, whereas neither olfactory neuroblastoma nor malignant melanoma revealed any positive reaction. The above results suggest that EBV infection is closely associated with sinonasal undifferentiated carcinomas, and that some malignant melanomas may also have a relationship with its infection. For the differential diagnosis of SSRCT, it is important to evaluate EBV infection along with immunohistochemical staining for cytokeratins and S-100 protein. The overexpression of p53 protein was found to be related to the oncogenesis of sinonasal undifferentiated carcinoma; however, there was no association between its overexpression and malignant melanoma or olfactory neuroblastoma.

Basaloid squamous cell carcinoma of the sinonasal tract

BACKGROUND

Basaloid squamous cell carcinoma (BSCC) is a high grade, aggressive variant of squamous cell carcinoma with a predilection for the larynx, hypopharynx, tonsils, and base of the tongue. To the authors' knowledge, BSCC originating in the nasal cavity and paranasal sinuses rarely has been reported.

METHODS

Fourteen cases of BSCC involving the nasal cavity and paranasal sinuses were identified in the files of the Otolaryngic-Head and Neck Pathology Tumor Registry of the Armed Forces Institute of Pathology from 1975-1997. Clinical records and follow-up were available in all cases. Paraffin blocks were available for histochemical and immunohistochemical studies in all cases.

RESULTS

There were 7 females and 7 males, ages 32-86 years (median, 66.5 years; mean, 62 years). The patients presented primarily with a mass lesion and unilateral nasal obstruction. In nine patients the tumor was confined to the nasal cavity. In three patients the tumor involved the sinuses alone and in two patients the tumor involved the nasal cavity and paranasal sinuses. Histologically, the tumors were widely invasive with a variety of growth patterns, including lobular, solid, trabecular, cribriform, and fascicular. The neoplastic infiltrate included predominantly pleomorphic, basaloid-appearing cells with hyperchromatic nuclei, inconspicuous to prominent nucleoli, and a variable amount of eosinophilic to clear-appearing cytoplasm. Mitotic figures, including atypical forms, were readily apparent as was necrosis (individual cell and comedo-type). Foci of squamous differentiation were limited in extent but were found in all cases and included squamous whorls, individual cell keratinization, and intercellular bridges. Intraepithelial dysplasia, carcinoma in situ, or invasive squamous carcinoma was present in all cases. Other histologic features included intercellular stromal hyalinization and peripheral nuclear palisading. In two cases, neural-type rosettes were found. Immunoreactivity for a variety of epithelial markers including cytokeratin (AE1/AE3/LP34), CAM 5.2, 34betaE12, CK7, and epithelial membrane antigen was present in all cases. Variable reactivity was present with vimentin, actins (smooth muscle and muscle specific), neuron specific enolase, S-100 protein, glial fibrillary acidic protein, CK20, carcinoembryonic antigen, Leu7, and Ewing's marker. Chromogranin, synaptophysin, neurofibrillary protein, leukocyte common antigen, HMB-45, desmin, and Epstein-Barr virus latent membrane protein were absent. Surgical resection was the treatment of choice. Eight patients had recurrent or persistent tumor and metastatic disease occurred in five patients. At last follow-up, 7 patients (50%) had died of disease with a median survival of 12 months from the time of diagnosis and 3 patients were alive with disease over periods ranging from 8 months-5 years. Of the 4 remaining patients, 2 were alive without disease at 1 month and 5 years, respectively, 1 patient was lost to follow-up with no evidence of tumor at 3 years, and 1 patient had died of unrelated causes with no evidence of disease.

CONCLUSIONS

Sinonasal BSCC is a histologically distinct variant of squamous cell carcinoma with pathologic features and aggressive biologic behavior similar to BSCC localized to more common mucosal sites of the upper aerodigestive tract.

Primary mucosal melanomas of the nasal cavity and paranasal sinuses. A clinicopathological analysis of 14 cases

We present 14 patients with primary sinonasal melanomas (SM) identified from 1984-1997 in our archives (11/14 lateral nose, 1/14 nasal septum, 2/14 paranasal sinuses; 8M/6F, mean age 67.7 years, range 39-88 years). Survival was poor (median 9 months) with death related to extensive local disease and/or widespread hematogenous metastases. The following histological subtypes were identified in descending order: amelanotic small blue cell, pleomorphic, epithelioid, spindle cell and myxoid. High mitotic rate and vascular invasion, absence of tumor-infiltrating lymphocytes and regression were features shared by all SM. Negative staining of B- and T-cell markers, LCA, neuroendocrine markers such as NSE, chromogranin and synaptophysin, and CK-negativity excluded olfactory neuroblastoma, small cell undifferentiated carcinoma, and lymphoma. S-100 protein was expressed in all SM, but demonstrated variable staining intensity with areas of complete negativity. HMB45 was strongly and uniformly (>80%) expressed in all undifferentiated small blue cell SM. The pigmented SM were predominantly HMB45-negative. The strong HMB45 staining in amelanotic small blue cell SM is explained by the reaction of HMB45 antibody with an oncofetal antigen found in immature melanosomes. In these poorly differentiated amelanotic malignant melanomas, antibody to HMB45 proved to be a superb diagnostic marker. We therefore strongly advocate the inclusion of HMB45 antibody in the panel of antibodies for initial work-up of undifferentiated mucosal neoplasms, since a negative S-100 stain in small biopsy material may result in incorrect classification of these neoplasms.

[Determination of estrogen receptor and progesterone receptor of the sinonasal malignant neoplasms]

To examine the relationship between sex steroid receptor and sinonasal malignant neoplasms, estrogen receptor (ER) and progesterone receptor (PR) were determined in 25 cases of sinonasal malignant neoplasms, 10 cases of sinonasal papillomas, 31 cases of nasal polyps and 12 cases of normal nasal mucosa. The determination of ER and PR was done by radioligand binding assay of receptors (RBAR). The results indicated that sinonasal malignant neoplasms had higher concentrations of ER and PR binding protein, while sinonasal papillomas, nasal polyps and normal nasal mucosa were found to contain lower concentration of ER and PR, and the differences were significant. (P < 0.01). It is suggested that sinonasal malignant neoplasms might depend on ER and PR.

Detection of Epstein-Barr Virus Genome in Sinonasal Undifferentiated Carcinoma by Use of in Situ Hybridization

Associations between Epstein-Barr virus and undifferentiated carcinomas of nasopharynx, parotid gland, and thymus have recently been reported. Epstein-Barr virus has also been associated with malignant lymphoma of the nose and paranasal sinuses. These findings raise the possibility that Epstein-Barr virus may additionally be linked to undifferentiated carcinoma of the nose and paranasal sinuses (SNUC), an uncommon but distinctive and highly aggressive neoplasm. Histologically, SNUC consists of small and medium cells, the precise characterization of which often requires immunocytochemical analysis. This study investigates the presence of DNA sequences of Epstein-Barr virus in biopsy specimens of 13 cases of SNUC that were defined immunocytochemically by use of previously reported criteria. In situ hybridization was used to detect Epstein-Barr virus genome in different cell types in routinely processed, paraffin-embedded tissues. Epstein-Barr virus-specific DNA sequences were detected in tumor cells of SNUC specimens from 5 of the 13 cases examined. No correlation was found between positive hybridization and primary tumor site, morphologic subtype, or disease course. Epstein-Barr virus DNA was detected in 38% (5 of 13) of the SNUC samples analyzed. This finding suggests that this virus may play a role in the pathogenesis of this rare neoplasm.

Detection of Epstein-Barr virus genome in sinonasal undifferentiated carcinoma by use of in situ hybridization

Associations between Epstein-Barr virus and undifferentiated carcinomas of nasopharynx, parotid gland, and thymus have recently been reported. Epstein-Barr virus has also been associated with malignant lymphoma of the nose and paranasal sinuses. These findings raise the possibility that Epstein-Barr virus may additionally be linked to undifferentiated carcinoma of the nose and paranasal sinuses (SNUC), an uncommon but distinctive and highly aggressive neoplasm. Histologically, SNUC consists of small and medium cells, the precise characterization of which often requires immunocytochemical analysis. This study investigates the presence of DNA sequences of Epstein-Barr virus in biopsy specimens of 13 cases of SNUC that were defined immunocytochemically by use of previously reported criteria. In situ hybridization was used to detect Epstein-Barr virus genome in different cell types in routinely processed, paraffin-embedded tissues. Epstein-Barr virus-specific DNA sequences were detected in tumor cells of SNUC specimens from 5 of the 13 cases examined. No correlation was found between positive hybridization and primary tumor site, morphologic subtype, or disease course. Epstein-Barr virus DNA was detected in 38% (5 of 13) of the SNUC samples analyzed. This finding suggests that this virus may play a role in the pathogenesis of this rare neoplasm.

Biologic markers of invasive pituitary adenomas involving the sphenoid sinus

The biologic behavior of invasive pituitary adenomas is poorly understood and appears to be intermediate between intrasellar adenomas and pituitary carcinoma. Utilizing immunohistochemistry on tissue sections, we examined 10 invasive pituitary adenomas involving the sphenoid sinus with a panel of cellular and molecular markers and compared the results with 10 noninvasive pituitary adenomas and five normal pituitary glands. The panel included Ki-67 and PCNA (proliferation cell nuclear antigen), cell proliferation indicators; interleukin 6 (IL-6), a multifunctional cytokine; heat shock protein 27 (HSP 27), a stress response protein; and p53, a tumor suppressor gene product. We found strong expression of IL-6 in normal pituitary glands, 20% of noninvasive and 50% of invasive adenomas. HSP 27 was absent in normal glands and present in 10% of noninvasive and 50% of invasive adenomas. The Ki-67 and PCNA proliferation index was above normal but was essentially the same in the two groups. p53 was not detected in any specimens. We propose that both IL-6 and HSP 27 may be markers of biologic aggression in pituitary adenomas.

Sex steroid receptors in papilloma, normal mucosa and polyps of the nose

Sex steroid hormone receptors (SSHR) were determined in 14 cases of sinonasal papillomas, 17 cases of nasal polyps and in the normal nasal mucosa of 13 patients. The determination of SSHR was done by the dextran-coated charcoal assay from cytosol protein. All the cases of sinonasal papilloma were SSHR negative, while some specimens of normal nasal mucosa contained small amounts of SSHR. In addition, some cases of nasal polyps were found to contain low concentrations of the receptors, but concentrations were lower than those found in normal mucosa. Although nasal papillomas are more common in men than in women, this study shows that SSHR do not play any role in the development of these tumors.

Detection of Epstein-Barr viral RNA in sinonasal undifferentiated carcinoma from Western and Asian patients

Undifferentiated carcinoma of the nasopharynx has a well-known association with Epstein-Barr virus (EBV), but only an inconsistent relationship has been identified in undifferentiated carcinomas occurring at other sites. We investigated 22 formalin-fixed, paraffin-embedded cases of sinonasal undifferentiated carcinomas (SNUCs) occurring in Western and Asian patients. A highly sensitive in situ hybridization method was performed using an antisense oligonucleotide probe to the EBER1 gene of EBV. We identified EBV RNA in seven of 11 SNUCs from Asian patients, but in none of the Western SNUC patients (0/11). The EBER1 signal was present in all or virtually all of the tumor cell nuclei in the seven EBV-RNA-positive Asian SNUCs. The latent membrane protein-1 (LMP1) of EBV was not identified in any of the five positive cases tested. Our results suggest that genetic predisposition or environmental/geographical cofactors play an important role in determining the strength of the association of SNUC with EBV.

[Magnetic resonance spectroscopy of naso-sinus tumors]

Magnetic Resonance Spectroscopy (MRS) has been developed as a new application of nuclear magnetic resonance. By means of MRS, internal chemical information can be non-invasively measured. In this study, the 31P MRS of naso-sinus tumors was measured and evaluated. The peaks of 31P MRS, such as Adenosine tri-phosphate (ATP), Creatine phosphate (PCr), Phosphodiester (PME), Inorganic phosphate (Pi), and Phosphomonoester (PME) can be identified. Phosphomonoesters (PME) are precursors of membrane phospholipids. Phosphodiesters (PDE) are metabolites of phospholipids. Compared with benign tumors, the 31P MRS of malignant tumors shows a higher PME peak and lower PDE and PCr peaks. These results indicate that malignant tumors are characterized by chemical changes in membrane metabolism.

Presence of urokinase-type plasminogen activator (u-PA) in tissue extracts of antrochoanal polyp

Using a biochemical technique, the authors characterized and identified a plasminogen activator (PA) derived from tissue extracts of antrochoanal polyp (AP) and paranasal mucous membrane (PMM) with chronic sinusitis. The results of fibrin zymography indicated that the tissue extracts of AP revealed two lytic zones and that those of PMM revealed a single lytic zone on fibrin-agarose plates. One of the AP zones exhibited the same relative mobility as the PMM zone (molecular weight: 65 kd), while the other AP zone had a smaller molecular weight (about 54 kd). Goat immunoglobulin G (IgG) fraction of antihuman uterine tissue-type plasminogen activator (t-PA) inhibited the 65-kd lytic zones of AP and PMM. Antihuman low-molecular-weight urokinase inhibited only the 54-kd lytic zone of AP, and nonspecific goat IgG failed to inhibit any of the lytic zones. On the other hand, 10(-2) mol trans 4-(aminomethyl)cyclohexane-carboxylic acid (t-AMCHA) inhibited all of the lytic zones. No lytic zones could be observed on plasminogen-free fibrin-agarose plates. These findings confirmed that the tissue extracts of PMM contained t-PA, and that those of AP contained both t-PA and urokinase-type plasminogen activator (u-PA). In addition, it appeared that u-PA in inflammatory tissue was related to proliferative changes of the mucous membrane.

[Flow cytometric analysis of DNA ploidy in nasosinal papilloma]

Using paraffin embedded specimens taken from 32 patients with histologically benign nasosinal papillomas, we conducted nuclear DNA analysis by flow cytometry and studied the biological degree of malignancy in this disease. Aneuploidy, which is frequently observed in malignant tumors was not seen in any of these nasosinal papilloma cases. Age did not affect either S+G2M % or polyploid %, two parameters that reflect cell proliferation capacity. Both parameters, S+G2M % and polyploid %, were higher in inverted papillomas which are more likely to become malignant than epithelial papillomas. In recurrent cases of nasosinal papilloma both S+G2M % and polyploid % were higher than in nonrecurrent cases. Moreover, the polyploid % was significantly different, supporting speculation that this can be used as a parameter for predicting recurrence of nasosinal papilloma.

Cylindrical cell papilloma of the nasal cavity and paranasal sinuses. A histochemical and cytochemical study

A cylindrical cell papilloma occurring in the sino-nasal mucosa of a 61-year-old woman was studied histochemically at both light and electron microscopic levels. The cylindrical cells demonstrated distended intracytoplasmic microcysts with numerous microvillous projections on the apical cell membrane. The retained mucosubstance in the cystic spaces stained intensely with HID-TCH-SP sequence and showed no apparent communication with the extracellular space. These findings indicate that the cylindrical cells may be of mucous-secreting cell derivation, being derived from cells possessing abnormal and/or failed secretory function. The property of sulfated mucin in the 'cylindric' intracytoplasmic cysts is suggested to be the result of endodermal displacement or metaplasia of the Schneiderian epithelium.

Fatty acids in lipids of nasoethmoidal polyps

In 29 samples of recurrent nasoethmoidal polyps removed from 11 patients, the relative fatty acids composition was established by means of gas chromatography. Four samples of nasal mucosa of patients without polyps were subjected to the same procedure. A significant increase in the content of linoleic acid (18:2, n-6) as well as in the index "linoleic acid/oleic acid" was found. Proportion of arachidonic acid was high both in polyps and in control samples of nasal mucosa. An orientation examination of fatty acids in individual fractions of lipids, compared to serum values, showed that the main source of arachidonic acid appears to be phospholipids.

[Flow cytometric analysis of DNA content in paraffin-embedded tissue in head and neck cancer--evaluation of malignant potential and carcinogenic process of nasoparanasal tumor]

Flow cytometric analysis of DNA content from paraffin-embedded material has become an important diagnostic and prognostic method in clinical pathology and investigative oncology. We analyzed nuclear DNA content in order to detect possible alternations in DNA histogram as an indicator of malignant potential and carcinogenic process of head and neck tumor. DNA histograms were evaluated by three parameters; DNA aneuploidy, S + G2M% : rate of S and G2 + M phase cells as a parameter for growth kinetics, and polyploid%: rate of more than tetraploid cells as a parameter of nuclear atypia. We took a simple method for the selection of tumor area in paraffin blocks using a consecutive section stained with hematoxylin-eosin as a diagnostic guideline. This technique can be used either to enrich the sample to be analyzed with aimed area or to analyze histopathologically different compartments of the tumor. We compared the result of fresh and fixed specimens in 20 materials. DNA aneuploidy was found in both specimens of the same two carcinomas and there was a close relationship between them in S + G2M% (p less than 0.01) and polyploid% (p less than 0.05). We studied two cases of maxillary carcinoma with coexisting inverted papilloma as precancerous lesion. In one case S + G2M% and polyploid% were 16%, 1.15% in nasoparanasal papilloma, 20.5%, 4.0% in papilloma with atypia, and 33%, 8.25% in carcinoma, respectively. In the other case those were 3%, 0.1% in transitional papilloma, 8%, 0.9% in inverted papilloma, and 13%, 4.0% in carcinoma, respectively. There was positive correlation between these two parameters and histopathological grade. Finally we analyzed nuclear DNA content from fixed specimens in three groups; 33 papillomas, 15 maxillary carcinomas and 23 normal epithelia. Mean values of S + G2M% and polyploid% were as follows: 2.1%, 2.6% in normal epithelia, 19.6%, 8.9% in papillomas, and 34.8%, 18.1% in carcinomas. There was statistical significance between three groups (p less than 0.01). DNA aneuploidy was only found in 6 of 15 carcinomas (40%). The results demonstrated that S + G2M% and polyploid% were significantly compared with the histopathological grade of atypia and DNA aneuploidy was a marker of carcinoma. We suggest that DNA histogram is a good indicator for biological activity and that the increased S + G2M% and polyploid% may indicate carcinogenic process. We also suggest that tumor progression may lead to acquired genetic variability and DNA aneuploidy.