Radek Sima

Mammary analogue secretory carcinoma of salivary glands, containing the ETV6-NTRK3 fusion gene: a hitherto undescribed salivary gland tumor entity.

We present a series of 16 salivary gland tumors with histomorphologic and immunohistochemical features reminiscent of secretory carcinoma of the breast. This is a hitherto undescribed and distinctive salivary gland neoplasm, with features resembling both salivary acinic cell carcinoma (AciCC) and low-grade cystadenocarcinoma, and displaying strong similarities to breast secretory carcinoma. Microscopically, the tumors have a lobulated growth pattern and are composed of microcystic and glandular spaces with abundant eosinophilic homogenous or bubbly secretory material positive for periodic acid-Schiff, mucicarmine, MUC1, MUC4, and mammaglobin. The neoplasms also show strong vimentin, S-100 protein, and STAT5a positivity. For this tumor, we propose a designation mammary analogue secretory carcinoma of salivary glands (MASC). The 16 patients comprised 9 men and 7 women, with a mean age of 46 years (range 21 to 75). Thirteen cases occurred in the parotid gland, and one each in the minor salivary glands of the buccal mucosa, upper lip, and palate. The mean size of the tumors was 2.1 cm (range 0.7 to 5.5 cm). The duration of symptoms was recorded in 11 cases and ranged from 2 months to 30 years. Clinical follow-up was available in 13 cases, and ranged from 3 months to 10 years. Four patients suffered local recurrences. Two patients died, 1 of them owing to multiple local recurrences with extension to the temporal bone, and another owing to metastatic dissemination to cervical lymph nodes, pleura, pericardium, and lungs. We have shown a t(12;15) (p13;q25) ETV6-NTRK3 translocation in all but one case of MASC suitable for analysis. One case was not analyzable and another was not available for testing. This translocation was not found in any conventional salivary AciCC (12 cases), nor in other tumor types including pleomorphic adenoma (1 case) and low-grade cribriform cystadenocarcinoma (1 case), whereas ETV6-NTRK3 gene rearrangements were proven in all 3 tested cases of mammary secretory carcinoma. Thus, our results strongly support the concept that MASC and AciCC are different entities.

Interaction of the tick immune system with transmitted pathogens.

Ticks are hematophagous arachnids transmitting a wide variety of pathogens including viruses, bacteria, and protozoans to their vertebrate hosts. The tick vector competence has to be intimately linked to the ability of transmitted pathogens to evade tick defense mechanisms encountered on their route through the tick body comprising midgut, hemolymph, salivary glands or ovaries. Tick innate immunity is, like in other invertebrates, based on an orchestrated action of humoral and cellular immune responses. The direct antimicrobial defense in ticks is accomplished by a variety of small molecules such as defensins, lysozymes or by tick-specific antimicrobial compounds such as microplusin/hebraein or 5.3-kDa family proteins. Phagocytosis of the invading microbes by tick hemocytes is likely mediated by the primordial complement-like system composed of thioester-containing proteins, fibrinogen-related lectins and convertase-like factors. Moreover, an important role in survival of the ingested microbes seems to be played by host proteins and redox balance maintenance in the tick midgut. Here, we summarize recent knowledge about the major components of tick immune system and focus on their interaction with the relevant tick-transmitted pathogens, represented by spirochetes (Borrelia), rickettsiae (Anaplasma), and protozoans (Babesia). Availability of the tick genomic database and feasibility of functional genomics based on RNA interference greatly contribute to the understanding of molecular and cellular interplay at the tick-pathogen interface and may provide new targets for blocking the transmission of tick pathogens.

Morphologic diversity of malignant neoplasms arising in preexisting spiradenoma, cylindroma, and spiradenocylindroma based on the study of 24 cases, sporadic or occurring in the setting of Brooke-Spiegler syndrome.

The authors present a series of 24 malignant neoplasms arising in preexisting benign spiradenoma (20), cylindroma (2), and spiradenocylindroma (2). Nineteen patients (12 females, 7 males; age range, 41 to 92 y) had a solitary neoplasm (size range, 2.2 to 17.5 cm; median 4 cm), whereas the remaining 5 (4 females, 1 male; age range, 66 to 72 y) manifested clinical features of Brooke-Spiegler syndrome (BSS), an autosomal dominantly inherited disease characterized by widespread, small, benign neoplasms on which background larger malignant lesions appeared. Microscopically, all cases showed the residuum of a preexisting benign neoplasm. The malignant components of the lesions were variable and could be classified into 4 main patterns, occurring alone or in combination: 1) salivary gland type basal cell adenocarcinoma-like pattern, low-grade (BCAC-LG); 2) salivary gland type basal cell adenocarcinoma-like pattern, high-grade (BCAC-HG); 3) invasive adenocarcinoma, not otherwise specified (IAC-NOS); and 4) sarcomatoid (metaplastic) carcinoma. In 1 case of IAC-NOS, an in situ adenocarcinoma was also found, presumed to have evolved from an adjacent adenomatous and atypical adenomatous component. Cases harboring a sarcomatoid carcinoma featured a malignant epithelial component composed of varying combinations of BCAC-HG, BCAC-LG, IAC-NOS, or squamous cell carcinoma, whereas the sarcomatoid component appeared as either a pleomorphic or spindle-cell sarcoma. Additionally, in 2 cases there were foci of heterologous chondrosarcomatous differentiation and in 1 case there was rhabomyosarcomatous differentiation. Of the 21 patients with available follow-up (range, 3 mo-15 y; average 4.8 y; median 3.5 y), 10 were without evidence of disease, 1 was alive with metastatic disease, 1 was alive with BSS, 3 developed local recurrences, 4 had died of disease, and 2 were dead of other causes. The histologic pattern of the malignant neoplasm correlated to some extent with the clinical course. BCAC-LG neoplasms showed a less aggressive course, with local recurrences but no distant metastases, whereas the BCAC-HG neoplasms typically followed a highly aggressive course resulting in the death 3 of 6 patients with BCAC-HG. Patients with sarcomatoid carcinoma had a relatively good survival. Molecular genetic investigations revealed no mutations in the CYLD gene in the 4 sporadic cases investigated. One patient with BSS revealed a novel missense germline mutation in exon 14 (c. 1961T>A, p. V654E), whereas a living descendant of another deceased patient demonstrated a recurrent nonsense germline mutation in exon 20 (c. 2806C>T, p. R936X). Given the morphologic diversity and complexity of the neoplasms in question, we propose using a more specific terminology with the precise description of the neoplasm components, rather than generic and less informative terms such as “spiradenocarcinoma” or “carcinoma ex cylindroma.”

Renal angiomyoadenomatous tumor: morphologic, immunohistochemical, and molecular genetic study of a distinct entity

We present a series of a distinct tumorous entity named renal angiomyoadenomatous tumor (RAT). Five cases were retrieved from the consultation files of the authors. Histologic and immunohistochemical features were evaluated. Sequencing analysis of coding region of the VHL gene was carried out in all cases. The tumors were composed of admixture of an epithelial clear cell component and prominent leiomyomatous stroma. Epithelial cells formed adenomatous tubular formations endowed with blister-like apical snouts. All tubular/glandular structures were lined by a fine capillary network. The epithelial component was positive for epithelial membrane antigen, CK7, CK20, AE1-AE3, CAM5.2, and vimentin in all cases. In all analyzed samples, no mutation of the VHL gene was found. RAT is a distinct morphologic entity, being different morphologically, immunohistochemically, and genetically from all renal tumors including conventional clear cell carcinoma and mixed epithelial and stromal tumor of kidney.

Systems biology of tissue-specific response to Anaplasma phagocytophilum reveals differentiated apoptosis in the tick vector Ixodes scapularis.

Anaplasma phagocytophilum is an emerging pathogen that causes human granulocytic anaplasmosis. Infection with this zoonotic pathogen affects cell function in both vertebrate host and the tick vector, Ixodes scapularis. Global tissue-specific response and apoptosis signaling pathways were characterized in I. scapularis nymphs and adult female midguts and salivary glands infected with A. phagocytophilum using a systems biology approach combining transcriptomics and proteomics. Apoptosis was selected for pathway-focused analysis due to its role in bacterial infection of tick cells. The results showed tissue-specific differences in tick response to infection and revealed differentiated regulation of apoptosis pathways. The impact of bacterial infection was more pronounced in tick nymphs and midguts than in salivary glands, probably reflecting bacterial developmental cycle. All apoptosis pathways described in other organisms were identified in I. scapularis, except for the absence of the Perforin ortholog. Functional characterization using RNA interference showed that Porin knockdown significantly increases tick colonization by A. phagocytophilum. Infection with A. phagocytophilum produced complex tissue-specific alterations in transcript and protein levels. In tick nymphs, the results suggested a possible effect of bacterial infection on the inhibition of tick immune response. In tick midguts, the results suggested that A. phagocytophilum infection inhibited cell apoptosis to facilitate and establish infection through up-regulation of the JAK/STAT pathway. Bacterial infection inhibited the intrinsic apoptosis pathway in tick salivary glands by down-regulating Porin expression that resulted in the inhibition of Cytochrome c release as the anti-apoptotic mechanism to facilitate bacterial infection. However, tick salivary glands may promote apoptosis to limit bacterial infection through induction of the extrinsic apoptosis pathway. These dynamic changes in response to A. phagocytophilum in I. scapularis tissue-specific transcriptome and proteome demonstrated the complexity of the tick response to infection and will contribute to characterize gene regulation in ticks.

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.

Gastrointestinal stromal tumor of the pancreas: case report with documentation of KIT gene mutation

Sir, mesenchymal tumors of the pancreas are exceedingly rare, accounting for less than 1% of all pancreatic tumors, and most of them have been reported in small series or as single case reports. This group of pancreatic tumors includes leiomyosarcoma, malignant peripheral nerve sheath tumor, malignant fibrous histiocytoma, liposarcoma, rhabdomyosarcoma,hemangiopericytoma,schwannomaandsolitary fibrous tumor. In the gut, mesenchymal tumors are more common, and the majority of these are formed by gastrointestinal stromal tumors (GISTs). GISTs are defined as KIT-positive mesenchymal spindle cell or epithelioid neoplasms showing differentiation toward the interstitial cell of Cajal. GISTs occur most commonly in the stomach (60–70%), small intestine (20–25%), colorectum (5%) and esophagus (<5%). They were also occasionally reported in extragastrointestinal sites,suchasurinarybladder,gallbladder,omentumandmesentery[1].WereportacaseofaGIST of the pancreatic head in a 70-year-old woman exhibiting all diagnostic histopathological, immunohistochemical and molecular genetic features, which has not yet been properly documented in this location. Although Neto et al. publishedacaseofpancreatic GISTrecently,evaluationofc-kit mutations as well as computed tomography (CT) scan or microphotograph documenting pancreatic location of the tumor is missing in their report [7].

Cribriform adenocarcinoma of minor salivary gland origin principally affecting the tongue: characterization of new entity.

We present a series of 23 cases of a distinctive, hitherto poorly recognized low-grade adenocarcinoma, with several histologic features reminiscent of papillary carcinoma of the thyroid, and which mostly but not exclusively occurs in the tongue. All the tumors were unencapsulated and were divided into lobules that were composed mainly of cribriform and solid growth patterns. Therefore, we propose the name “cribriform adenocarcinoma of minor salivary gland origin (CAMSG).” All the patients were adults with a mean age at diagnosis of 55.8 years (range, 25 to 85 y). Fourteen of the 23 tumors were localized in the tongue, 3 in the soft palate, 2 in the retromolar buccal mucosa, 3 in the lingual tonsils, and 1 in the upper lip. Fifteen patients of 23 had synchronous metastases in the cervical lymph nodes at the time of diagnosis, bilateral in 3 cases. In 3 patients, the nodal metastasis was the first evidence of disease, later investigation revealing primary neoplasms in the base of tongue and tonsil, respectively. In addition, 1 patient developed a cervical lymph node metastasis 8 years after excision of a primary tumor of the tongue. Data on treatment and follow-up were available in 14 cases. The patients were treated by radical excision with clear margins (12 cases) or by simple excision (2 cases). Neck dissection was performed in 10 patients; 9 received radiotherapy, but none were treated by chemotherapy. Clinical follow-up ranged from 2 months to 13 years (mean, 6 y and 5 mo). Twelve patients are alive with no evidence of recurrent or metastatic disease after treatment, 1 patient died 2 years after surgery without evidence of tumor, and 1 patient is alive with recurrent tumor of the palate.

Cutaneous lymphoid hyperplasia and other lymphoid infiltrates of the breast nipple: a retrospective clinicopathologic study of fifty-six patients.

This study characterizes the clinicopathological spectrum of lymphoproliferations involving the breast nipple and/or areola. Morphologic, immunohistochemical, molecular-genetic, and clinical features of 58 specimens from 56 patients were analyzed. They were re-diagnosed as cutaneous lymphoid hyperplasia (CLH, n = 44); other benign lymphoid infiltrates (OBLI, n = 8); peripheral T-cell lymphoma, not otherwise specified (n = 1); cases with overlapping features of CLH and B-cell lymphoma (n = 3), one of them composed of spindle cells. Cutaneous lymphoid hyperplasia infiltrates were dense, composed mainly of B cells forming follicles with germinal centers (GC). Cutaneous lymphoid hyperplasia frequently showed features suggesting a malignancy as coalescing follicles with non-polarized germinal centers lacking mantle zones, and smudged infiltrates of lymphoid cells spreading into collagen (often as “Indian files”), smooth muscle, vessel walls, and nerve sheaths. Only two cutaneous lymphoid hyperplasias recurred; otherwise all patients are without disease (mean follow-up 62 months). Monoclonal rearrangement of immunoglobulin heavy chain gene was detected in five, and of T-cell receptor γ gene in two cutaneous lymphoid hyperplasias using polymerase chain reaction (PCR), but the patients fared well too. In 47% of cases Borrelia burgdorferi was detected by polymerase chain reaction and/or serology, of which one was monoclonal. We conclude that cutaneous lymphoid hyperplasia is the most common lymphoproliferation of the breast nipple, rarely recognized clinically, and often overdiagnosed histologically as lymphoma.

Cutaneous Hidradenocarcinoma: A Clinicopathological, Immunohistochemical, and Molecular Biologic Study of 14 Cases, Including her2/neu Gene Expression/amplification, tp53 Gene Mutation Analysis, and t(11;19) Translocation

We present a series of 14 cases of cutaneous hidradenocarcinomas. The patients included 6 women and 8 men ranging in age at diagnosis from 34 to 93 years. All but 1 patient presented with a solitary nodule. There was no predilection site. One patient presented with multiple lesions representing metastatic nodules. Of 12 patients with available follow-up, 2 died of disease, whereas the remaining 10 patients were alive but 3 of them experienced a local recurrence in the course of the disease. Grossly, the tumors ranged in size from 1.2 to 6 cm. Microscopically, of the 14 primary tumors, 9 showed low-grade cytomorphology, whereas the remaining 5 neoplasms were high-grade lesions. The residuum of a hidradenoma was present in 5 of the 14 primaries. The mitotic rate was highly variable, ranging from 2 to 64 mitoses per 10 high-power field. The cellular composition of the tumors varied slightly, with clear cells, epidermoid cells, and transitional forms being present in each case. In 1 case, there was metaplastic transformation into sarcomatoid carcinoma. Glandular differentiation varied from case to case and appeared most commonly as simple round glands or as cells with intracytoplasmic lumens. Necrosis en masse was detected in 8 specimens. One specimen represented a reexcision and was unusual as it showed a well-demarcated intradermal proliferation of relatively bland clear cells accompanied by an overlying intraepidermal growth of clear cells resembling hidradenoacanthoma simplex. Despite the bland appearance, the tumor metastasized to a lymph node. Immunohistochemically, 5 of the 8 specimens studied for Her2/neu expression were negative, whereas 3 specimens from 2 cases yielded score +2, but all the 3 specimens with score 2+ subsequently proved negative for Her2/neu gene amplification by fluorescence in situ hybridization. Of 10 primaries studied, 4 tumors showed positive p53 immunoreaction in more than 25% of the cells comprising the malignant portion of the lesions, in 2 cases, a minority of the neoplastic cells (10%-20%) demonstrated nuclear staining, whereas the remaining 4 cases were negative. Of 9 specimens of hidradenocarcinoma studied for TP53 mutations, 2 harbored mutations, whereas the remaining 7 specimens showed the wild-type sequence. Of 11 specimens studied for translocation t(11;19), 2 cases harbored the translocation. It is concluded that cutaneous hidradenocarcinomas show some microscopic heterogeneity and comprise both low- and high-grade lesions that cytologically are similar to their benign counterpart, the hidradenoma. Within the spectrum of low-grade lesions, there seem to exist tumors almost indistinguishable from hidradenomas but still being capable of regional or distant metastasis. Similar to hidradenomas, hidradenocarcinomas show a t(11;19) translocation, but it is a significantly rarer event. Even rarer is the amplification of the Her2/neu gene. Of note is the relatively low frequency of TP53 mutations despite a high rate of p53 protein expression at the immunohistochemical level.