Dmitry V. Kazakov

WHO/EORTC classification of cutaneous lymphomas 2005: histological and molecular aspects.

Abstract:  The new WHO/EORTC classification for cutaneous lymphomas comprises mature T‐cell and natural killer (NK)‐cell neoplasms, mature B‐cell neoplasms, and immature hematopoietic malignancies. It reflects the unique features of lymphoproliferative diseases of the skin, and at the same time it is as compatible as possible with the concepts underlying the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. This article reviews the histological, phenotypical, and molecular genetic features of the various nosological entities included in this new classification. These findings always have to be interpreted in the context of the clinical features and biologic behavior.

Clinicopathological spectrum of mycosis fungoides

Cutaneous lymphomas represent a heterogeneous group of T‐, NK‐ and B‐cell neoplasms, with mycosis fungoides (MF) being the most common subtype. MF has a plethora of clinicopathological manifestations. Many variants of this lymphoma differ substantially from the ‘classical’ Alibert–Bazin disease and are therefore sometimes referred to as ‘atypical’ forms of the disease. This review addresses the whole clinicopathological spectrum of mycosis fungoides with respect to epidemiology, clinical, histopathological, immunophenotypic and genotypic features and the clinical course and prognosis of its variants: classical, erythrodermic, follicular, syringotropic, bullous/vesicular, granulomatous, poikilodermic, hypo‐ and hyperpigmented, unilesional, palmoplantar, hyperkeratotic/verrucous, vegetating/papillomatous, ichthyosiform, pigmented purpura‐like, pustular and mucosal involvement in MF.

Mucinous Carcinoma of the Skin, Primary, and Secondary A Clinicopathologic Study of 63 Cases With Emphasis on the Morphologic Spectrum of Primary Cutaneous Forms: Homologies With Mucinous Lesions in the Breast

We present the largest series of mucinous carcinoma involving the skin, describing the histopathologic, immunohistochemical, electron microscopic, and cytogenetic findings. Our aim was fully to characterize the clinicopathologic spectrum and compare it with that seen in the breast. In addition, we wished to reevaluate the differential diagnostic criteria for distinguishing primary mucinous carcinomas from histologically similar neoplasms involving the skin secondarily, and study some aspects of their pathogenesis. We demonstrate that primary cutaneous mucinous carcinomas span a morphologic spectrum compatible to their mammary counterparts. Both pure and mixed types can be delineated morphologically, and some lesions have mucocele-like configurations. Most lesions seem to originate from in situ lesions that may represent, using mammary pathology terminology, ductal hyperplasia, atypical ductal hyperplasia, or ductal carcinoma in situ or a combination of the three. Inverse cell polarity appears to facilitate the progression of the changes similar to lesions in the breast. The presence of an in situ component defines the neoplasm as primary cutaneous, but its absence does not exclude the diagnosis; although for such neoplasms, full clinical assessment is essential. Mammary mucinous carcinoma involving the skin: all patients presented with lesions on chest wall, breast, axilla, and these locations can serve as clue to the breast origin. Microscopically, cutaneous lesions were of both pure and mixed type, and this correlated with the primary in the breast. Dirty necrosis was a constant histologic finding in intestine mucinous carcinomas involving the skin, and this feature may serve as a clue to an intestinal origin.

Granulomatous mycosis fungoides and granulomatous slack skin: a multicenter study of the Cutaneous Lymphoma Histopathology Task Force Group of the European Organization For Research and Treatment of Cancer (EORTC)

BACKGROUND Granulomatous cutaneous T-cell lymphomas (CTCLs) are rare and represent a diagnostic challenge. Only limited data on the clinicopathological and prognostic features of granulomatous CTCLs are available. We studied 19 patients with granulomatous CTCLs to further characterize the clinicopathological, therapeutic, and prognostic features. OBSERVATIONS The group included 15 patients with granulomatous mycosis fungoides (GMF) and 4 with granulomatous slack skin (GSS) defined according to the World Health Organization-European Organization for Research and Treatment of Cancer classification for cutaneous lymphomas. Patients with GMF and GSS displayed overlapping histologic features and differed only clinically by the development of bulky skin folds in GSS. Histologically, epidermotropism of lymphocytes was not a prominent feature and was absent in 9 of 19 cases (47%). Stable or progressive disease was observed in most patients despite various treatment modalities. Extracutaneous spread occurred in 5 of 19 patients (26%), second lymphoid neoplasms developed in 4 of 19 patients (21%), and 6 of 19 patients (32%) died of their disease. Disease-specific 5-year survival rate in GMF was 66%. CONCLUSIONS There are clinical differences between GMF and GSS, but they show overlapping histologic findings and therefore cannot be discriminated by histologic examination alone. Development of hanging skin folds is restricted to the intertriginous body regions. Granulomatous CTCLs show a therapy-resistant, slowly progressive course. The prognosis of GMF appears worse than that of classic nongranulomatous mycosis fungoides.

Angioinvasive lymphomatoid papulosis: a new variant simulating aggressive lymphomas.

Lymphomatoid papulosis (LyP) belongs to the spectrum of primary cutaneous CD30-positive lymphoproliferative disorders. Clinically, LyP is characterized by a variable number of self-healing papulo-nodular lesions, with the typical waxing and waning course. Histologically, 4 types (A, B, C, and D) have been delineated. Angioinvasive growth and large ulcers are rare findings in LyP and simulate aggressive lymphoma. We retrospectively analyzed the clinicopathologic and molecular features of angioinvasive LyP in a series of 16 patients. This new form of LyP is characterized by oligolesional papules that rapidly ulcerate and evolve into large necrotic eschar-like lesions with a diameter of 1 to 4 cm and an angiocentric and angiodestructive infiltrate of small-sized to medium-sized atypical lymphocytes expressing CD30 and frequently CD8. As in other forms of LyP, the lesions underwent spontaneous regression after a few weeks. Recurrences were common, but the prognosis was excellent with no extracutaneous spread or disease-related deaths. Complete remission occurred in 9 of 16 patients (56%). This LyP variant should be distinguished from aggressive forms of angiocentric and angiodestructive and cytotoxic T-cell lymphomas. We propose the term LyP type E for this clinically and histologically unusual variant.

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.”

Lesions of anogenital mammary-like glands: an update.

Long considered to be ectopic breast tissue representing the caudal remnants of the milk ridges, anogenital mammary-like glands are nowadays thought to represent a normal constituent of the anogenital area. Lesions involving these glands, benign or malignant, epithelial or stromal manifest a striking similarity to their mammary counterparts. This review addresses the recent literature on lesions of anogenital mammary-like glands and our personal experience with various lesions related to these structures. Discussed are the normal anatomy and histology of these glands as well as the clinical presentation, histopathological and immunohistochemical features, molecular biological aspects, and differential diagnosis of various lesions involving anogenital mammary-like glands, including lactating adenoma, hidradenoma papilliferum, hidradenocarcinoma papilliferum, fibroadenomas, phyllodes tumor, pseudoangiomatous stromal hyperplasia, extramammary Paget disease, and other carcinomas. In addition, “nonspecific” epithelial or stromal changes some of which can be likened to similar changes occurring in a range of benign breast disease, including sclerosing adenosis, columnar cell lesions, ductal lesions and various metaplastic changes affecting epithelium and myoepithelium are discussed. Although lesions of anogenital mammary-like glands are often discussed in many dermatopathology textbooks in the context of cutaneous adnexal neoplasms we advocate that the best approach to the diagnosis of these lesions is to relate them to analogous well recognized lesions occurring in the breast, that is, through the eyes of a breast pathologist. This will enable their recognition, precise classification and should introduce greater uniformity in how they are reported in the literature so that more meaningful clinicopathological comparisons and correlations may be made.

Brooke-Spiegler syndrome: report of a case with combined lesions containing cylindromatous, spiradenomatous, trichoblastomatous, and sebaceous differentiation.

Brooke-Spiegler syndrome is an autosomal dominantly inherited disease with predisposition to cutaneous adnexal neoplasms, most commonly cylindromas and trichoepitheliomas. We report a patient in whom 11 lesions were removed from the scalp and face for various reasons over a period of 3 years. The histopathological survey revealed a plethora of benign adnexal neoplasms showing apocrine, follicular, and sebaceous differentiation occurring independently and conjointly. The histopathological spectrum in our patient included cylindromas, spiradenomas, trichoepitheliomas, small nodular trichoblastomas, and lymphadenomas. Many lesions had hybrid features of two or more neoplasms. By far the most common composite tumor was spiradenocylindroma. Some spiradenocylindromas demonstrated prominent sebaceous or trichoblastomatous differentiation or both. We suggest the terms “sebaceous spiradenocylindroma” and “trichospiradenocylindroma” for these lesions. The occurrence of sebaceous and trichoblastic differentiation in spiradenocylindromas is a further proof that spiradenoma and cylindroma are not eccrine tumors but neoplasms of the folliculosebaceousapocrine unit.

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.

Myxoid dermatofibrosarcoma protuberans: clinicopathologic, immunohistochemical, and molecular analysis of eight cases.

Dermatofibrosarcoma protuberans (DFSP) represents a locally aggressive mesenchymal neoplasm of skin and subcutis with characteristic clinicopathologic, immunohistochemical, and molecular findings. In addition to typical cases, morphologic variants such as pigmented, fibrosarcomatous, myofibroblastic, and granular cell DFSP have been described. Purely or predominantly myxoid DFSP is extremely rare, and may cause considerable diagnostic problems. Eight cases of predominantly myxoid DFSP were studied. Paraffin-embedded blocks and slides were retrieved from the files of the authors. Clinical data were obtained from the referring pathologists and dermatologists. Immunohistochemistry was performed using the ABC method, and three cases were studied by polymerase chain reaction technique. There were six male and two female patients (age range: 29 to 74 years). Locations included the inguinal area (three cases), thigh, upper arm, shoulder, abdominal wall, and back (one each). The patients were treated by wide excision as well as reexcision. Tumor size ranged from 1.5 to 12 cm. Histologically, a nodular growth with peripheral diffuse infiltration, as well as a diffusely infiltrating growth of relatively uniform spindled and stellated tumor cells containing slightly enlarged nuclei, was noted. Three cases were entirely myxoid, and in five cases more than 80% of the tumor area showed myxoid stromal changes. In two cases each, focal fibrosarcomatous and focal giant cell fibroblastoma-like changes were present. At least focally, hypocellular areas were evident in one case. Scattered enlarged tumor cells were seen in two cases. The mitotic rate ranged from 1 to 10 mitoses in 10 high-power fields. Numerous blood vessels with slightly fibrosed vessel walls were seen in seven cases. Immunohistochemically, tumor cells in all cases stained positively for CD34, and in one case each a focal expression of alpha-smooth muscle actin and epithelial membrane antigen (EMA) was noted. The remaining antibodies (CD99, CD31, S-100, Factor XIIIa) were all negative. Polymerase chain reaction technique showed in one case the characteristic COL1A1-PDGFB fusion gene. Follow-up information in seven cases (range: 2 months to 10 years; mean: 62 months; median: 48 months) revealed a local recurrence at 5 years. In conclusion, myxoid DFSP represents a very rare morphologic variant with characteristic changes that has to be distinguished from benign and malignant myxoid mesenchymal neoplasms as superficial angiomyxoma, superficial acral fibromyxoma, myxoid solitary fibrous tumor, myxoid perineurioma, low-grade myxofibrosarcoma, low-grade fibromyxoid sarcoma, myxoid liposarcoma, and myxoid synovial sarcoma.