Balanitis Xerotica Obliterans Associated With Differentiated Penile Intraepithelial Neoplasia and "Bramble-Bush" Elastic Fibers Accumulation: A Finding Not Specific for Penicillamine Intake.

We describe the association of balanitis xerotica obliterans and differentiated penile intraepithelial neoplasia (PeIN) with dermal elastosis and "bramble-bush" elastic fibers in a diabetic patient with no history of penicillamine intake. An 84-year-old man presented with urethral obstruction syndrome that required postectomy, meatotomy, and foreskin excision. Histopathological examination revealed changes of lichen sclerosus and differentiated PeIN. Orcein staining showed striking dermal elastosis and transepidermal elimination of elastic fibers. At higher magnification, multiple serrations and buds arising from the borders of the elastic fibers were observed giving the so-called bramble-bush appearance. Balanitis xerotica obliterans is considered a premalignant disease, and 14% of patients have evidence of PeIN. The differentiated subtype can be difficult to diagnose because of the minimal basal cell atypia, so a striking dermal elastosis, which may even occur before the neoplasm becomes invasive, may facilitate its diagnosis. The term "acquired perforating dermatosis" seems appropriate to describe those cases of perforating elastosis that occurs in adults with systemic diseases. The bramble-bush appearance of elastic fibers is not specific for penicillamine-induced elastopathy, and it may occur in other diseases, such as diabetes mellitus. This peculiar morphology of elastic fibers may be related to the enzymatic imbalance between matrix metalloproteinases and lysyl oxidase, an enzyme required for the cross-linking of elastic fibers.

Postradiation cutaneous pleomorphic rhabdomyosarcoma with extracellular collagen deposits reminiscent of so-called amianthoid fibers.

Rhabdomyosarcoma is a malignant mesenchymal neoplasm that rarely presents as primary skin tumor. So-called amianthoid fibers are hyalinized collagen mats that have been described in myofibroblastic tumors but not in rhabdomyosarcoma. A 65-year-old male developed a submandibular nodule 9 years after an oral squamous cell carcinoma, which had been treated with chemotherapy and radiotherapy. Histological examination of the nodule revealed a pleomorphic rhabdomyosarcoma with extracellular collagen deposits reminiscent of so-called amianthoid fibers. By immunohistochemistry, the tumor cells were positive for vimentin, desmin, smooth muscle actin (SMA), muscle-specific actin (MSA), CD10, CD56, CD99, ß-catenin and D2-40. However, only 15-20% of the tumor cells were positive for myoglobin, MyoD1 and myf-4/myogenin. We describe first so-called amianthoid fibers harboring blood capillaries in a rhabdomyosarcoma, suggesting that they are rigid collagen structures that lead to tumor vascularization. The low expression for myogenic regulatory proteins and strong expression for other markers may be misleading and do not contribute to the diagnosis of rhabdomyosarcoma.

Basaloid large cell lung carcinoma presenting as cutaneous metastasis at the colostomy site after abdominoperineal resection for rectal carcinoma.

The occurrence of a tumor at the colostomy site after abdominoperineal resection for rectal carcinoma is rare and it may be related to a previously resected carcinoma or another primary tumor. We report a 61-year-old man who developed an ulcerated skin nodule at her colostomy site 6 years after resection of a rectal adenocarcinoma. Histopathologically, the skin nodule was composed of atypical large and pleomorphic cells with high mitotic rate and they were arranged in nests and within lymphatic channels in the dermis. The neoplastic cells were immunoreactive for cytokeratin (CK) AE1/3, CK7, CK34ßE12, epithelial membrane antigen and vimentin while detection of human papillomavirus and Epstein-Barr virus DNA was negative. A diagnosis of basaloid large cell carcinoma of pulmonary origin was suggested and it was confirmed by computed tomography-guided fine needle aspiration of a right subpleural mass. A metastatic tumor at the colostomy site is an exceptional finding and may be the first manifestation of lung cancer, especially if it consist of pleomorphic large cells with high mitotic rate and basaloid immunophenotype.

Pseudogranulomatous Spitz nevus: a variant of Spitz nevus with heavy inflammatory infiltrate mimicking a granulomatous dermatitis.

Spitz nevus is a benign melanocytic proliferation that shows relatively characteristic clinicopathologic features. Despite this, Spitz nevus is clinically confused with many other lesions, and histopathologically it is sometimes difficult to distinguish it from melanoma. However, Spitz nevus rarely causes differential diagnostic problems with granulomatous dermatitis. This article describes an 8-year-old girl who presented with a nodule on her right arm, a clinical appearance of a pyogenic granuloma. Histopathologically, there was a dermal lesion composed of aggregates of large epithelioid cells surrounded by a heavy inflammatory infiltrate, mimicking a sarcoid-like granulomatous dermatitis. Immunohistochemistry showed epithelioid cells with strong nuclear and cytoplasmic staining with S-100 protein, thus establishing the diagnosis of a melanocytic tumor. The heavy T-cell lymphocytic infiltrate that accompanies the large epithelioid cells caused its granulomatous appearance. Molecular assessment showed H27H mutation in the HRAS gene. We suggest the term 'pseudogranulomatous' for this variant of Spitz nevus because it indicates that the lesion is not authentically granulomatous and simply mimics a granulomatous dermatitis.

Apocrine adenomyoepithelioma--a rare but distinctive primary sweat gland neoplasm.

Adenomyoepithelioma is a rare, microscopically distinctive tumor of the skin. This article explores an example that presented in the inguinal area in a 29-year-old woman, mimicking adenopathy. Histopathologically, the tumor included two different areas: a cystic area consisting of tubules and glands in hyalinized stroma and a solid area showing marked myoepithelial proliferation. The diagnosis of adenomyoepithelioma was confirmed by the presence of a biphasic immunoprofile, with expression of cytokeratins and epithelial membrane antigen in the glandular epithelium and with expression of vimentin and smooth muscle actin in the myoepithelial cells. An interesting novel finding was the expression of claudin-10 by myoepithelial cells, which to date has not been reported in the literature. The absence of metaplastic changes in the tumor stroma is crucial in the differential diagnosis with apocrine mixed tumor. Given that soft tissue adenomyoepithelioma is a benign tumor believed to originate from conventional sweat glands, its classification as a cutaneous myoepithelial neoplasm seems reasonable.

Signet ring cell melanocytic nevus: report of a case over trichilemmal cyst and review of the literature.

Different melanocytic nevi have been reported as being associated with dermal cysts. Signet ring cell melanocytic nevus is a rare variant of melanocytic nevus characterized by cells with signet ring morphology within a common melanocytic nevus. This article describes an exceptional case of melanocytic nevus composed exclusively of signet ring cells over a trichilemmal cyst. Histologically, above the cyst, there was a small, symmetrical and sharply demarcated lesion showing a compound proliferation of small, round, monomorphous cells with signet ring morphology. Immunohistochemically, signet ring cells were negative for cytokeratin AE1/3, leukocyte common antigen, HMB-45, and CD34. Occasionally, isolated signet ring cells were positive for S-100 and melan A. Melanocytic nevus composed of signet ring cells should raise the differential diagnosis with other cutaneous tumors exhibiting signet ring cells. Previous cases of this entity reported in the literature are also reviewed.

Morphological keys in the differential diagnosis of bladder inverted papilloma. Study of two types, trabecular and glandular.

OBJECTIVE: Inverted papilloma of the urinary bladder is an uncommon urothelial neoplasm that may be specially difficult to distinguish from urothelial carcinoma. METHODS: Two patients with obstructive symptoms and hematuria have been studied. In the transurethral resection, accidentally, one showed a papillary lesion in the context of nodular hyperplasia of the prostate, where as the other showed a polypoid tumor of the urinary bladder RESULTS: Histologically, in both cases, a bladder inverted papilloma was demonstrated, originating from the surface transitional epithelium. Basal cells exhibited peripheral palisading pattern in the trabecular form. In the glandular type, Dogiel or umbrella cells into the gland-like structures, were recognized. Immunohistochemical stains for p53 and Ki-67 were negative. Umbrella cells were positive for cytokeratin 20. CONCLUSIONS: Two cases of bladder inverted papilloma with relevant morphological aspects are presented, which we consider useful for the differential diagnosis with urothelial carcinoma.

[Fat-forming solitary fibrous tumor with NAB2/ STAT6 gene fusion. Case report of genial location and literature review]. / Tumor fibroso solitario variedad lipomatosa con fusión génica NAB2/STAT6. Estudio de un caso de localización geniana y revisión de la literatura.

The lipomatous variety solitary fibrous tumor is a soft tissue neoplasm composed of mature adipose tissue and hemangiopericytoma areas. A 53-year-old man consulted for facial asymmetry and maxillofacial magnetic resonance imaging showed a cystic lesion, 3 x 2 cm in size, in front of the anterior wall of the maxillary sinus. Histologically, there were dense spindle cells expressing CD34, CD99, Bcl-2, and STAT6, myxoid zones, hemangiopericytomatous blood vessels, and S100 positive adipocytes. NAB2/STAT6 gene fusion was revealed by RT-PCR. The main differential diagnosis was raised with the spindle cell lipoma and malignant variant of the lipomatous solitary fibrous tumor. STAT6 overexpression and NAB2/STAT6 gene fusion are specific for lipomatous solitary fibrous tumor and the presence of lipoblasts and atypical lipomatous tumor areas suggests malignancy. These tumors located in the head and neck region have a benign biological behavior.

MicroRNAs expression associated with aggressive clinicopathological features and poor prognosis in primary cutaneous melanomas.

Several studies have focused on identifying microRNAs involved in the pathogenesis of melanoma. However, its association with clinicopathological features has been scarcely addressed. The aim of this study is to identify microRNAs expression profiles related to aggressive clinicopathological and molecular features, and to analyze the association with melanoma survival. A retrospective and observational study was performed in a series of 179 formalin-fixed paraffin embedded primary cutaneous melanomas. First, a screening analysis on a discovery set (n = 22) using miRNA gene chip array (Affymetrix, Santa Clara, California, USA) was performed. Differentially expressed microRNAs were detected employing the software Partek Genomic Suite. Validation of four microRNAs was subsequently performed in the entire series (n = 179) by quantitative real time PCR (qRT-PCR). MicroRNAs expression screening analysis identified 101 microRNAs differentially expressed according to Breslow thickness (≤1 mm vs. >1 mm), 79 according to the presence or absence of ulceration, 78 according to mitosis/mm2 (<1 mitosis vs. ≥1 mitosis) and 97 according to the TERT promoter status (wt vs. mutated). Six microRNAs (miR-138-5p, miR-130b-3p, miR-30b-5p, miR-34a-5p, miR-500a-5p, miR-339-5p) were selected for being validated by qRT-PCR in the discovery set (n = 22). Of those, miR-138-5p, miR-130b-3p, miR-30b-5p, miR-34a-5p were selected for further analysis in the entire series (n = 179). Overexpression of miR-138-5p and miR-130b-3p was significantly associated with greater Breslow thickness, ulceration, and mitosis. TERT mutated melanomas overexpressed miR-138-5p. Kaplan-Meier survival analysis showed poorer survival in melanomas with miR-130b-3p overexpression. Our findings provide support for the existence of a microRNA expression profile in melanomas with aggressive clinicopathological features and poor prognosis.

Orbital soft tissue composite lymphoma presenting as recurrence of a nodal lymphoma with mantle and follicular cell components: A case report, literature review and guideline for the treatment of patients.

Composite lymphoma with mantle and follicular cell components is a challenging diagnosis. Flow cytometry, immunohistochemistry and molecular genetics are required to distinguish the two components, as often the more aggressive one is predominant and masks the other. A 58-year-old man with history of nodal composite lymphoma presented with right exophthalmos and diplopia. A head CT scan showed an orbital tumor. A biopsy of the tumor revealed a mantle cell lymphoma predominating over a follicular lymphoma. Immunoglobulin heavy chain and light chain rearrangements analysis by PCR proved that both components of the orbital tumor were recurrences of the same nodal composite lymphoma diagnosed two years earlier. The nodal lymphoma was composed of a follicular lymphoma and an in situ mantle cell neoplasia. Consensus view is that dominant lymphoma should be treated when needed but taking into account if the mantle cell lymphoma is an in situ neoplasia and if it expresses CD5 and SOX11.

[Solitary extramedullary plasmocytoma of tubaric tonsil]. / Plasmocitoma solitario extramedular de amígdala tubárica.

Several histopathological modalities of tumours can grow in the rhinopharynx. Solitary extramedullary plasmocytoma (SEP) is a low frequent variety of low-grade lymphoma. The aim of this work is to present a new case of SEP localized in rhinopharynx and to perform a review of diagnostic and therapeutic protocols of these neoplasias. They must be taken into account in the differential diagnosis of nasopharyngeal tumours.