Search

Amyloidoma, otherwise known as tumoral amyloidosis, is a localized deposition of amyloid (AL-type or AA type) without systemic amyloidosis. It is the rarest form of tissue amyloid deposition, and up to 7% of amyloidomas develop systemic amyloidosis.Cutaneous AL-type amyloidoma is considered by many authors as an unusual variant of primary cutaneous marginal zone lymphoma. Although cutaneous amyloidoma can form calcifications, ossification is extremely unusual, with only 1 case previously published to date.We report the case of a 75-year-old woman with voluminous and strikingly ossifying AL-type amyloidoma in the left pretibial skin. Her medical history included excision of hepatic hydatidic cysts 25 years prior and diffuse large B-cell lymphoma of the left parotid gland 8 years prior treated with chemotherapy and radiotherapy with complete response. After the diagnosis of amyloidoma, an extension study with cervical, chest, abdominal, and pelvic TC was performed, with no additional lesions found. Serum and protein electrophoresis revealed elevations in kappa light chain and IgA immunoglobulin levels but did not reveal monoclonal bands. In situ hybridization for immunoglobulin light chains showed monotypic kappa expression in plasma cells infiltrating the amyloidoma.Extensive ossification in amyloidomas can make diagnosis difficult; therefore, we describe an interesting case of this histopathologically peculiar amyloidoma.

There are no large series describing cutaneous histologic changes during treatment with vismodegib in locally advanced basal cell carcinoma (BCC).To analyze histologic changes in skin biopsy specimens from patients with locally advanced BCC treated with vismodegib.A descriptive, retrospective study of patients with locally advanced BCC treated with vismodegib between June 2012 and December 2017 at the Instituto Valenciano de Oncología, Spain. Nineteen patients were biopsied before and during the treatment with vismodegib, and we compared histologic changes observed.Seven patients (37%) achieved complete response, which was characterized by replacement of tumor stroma with a hyaline scar, lymphocytic inflammatory infiltrate, keratin formation, and infundibular cysts. Twelve patients (63%) achieved partial response; 5 showed no phenotypic changes, whereas 7 showed histologic changes; 5 cases showed metatypical differentiation; and 2 cases presented squamous differentiation. We observed no cases of squamous cell carcinoma arising at vismodegib treatment sites and no association between initial histologic subtype and clinical response.Many biopsy specimens were obtained by punch biopsy and may not be representative of the full tumors. We studied histologic changes only in complete and partial responses.Vismodegib can induce histologic changes toward metatypical or squamous differentiation of BCC in patients with partial response. Keratinizing phenomena were frequent, both in partial and complete response groups.

Cutaneous angiosarcoma (AS) is an uncommon, aggressive sarcoma whose incidence is rising because of the increasing use of radiation therapy, especially in breast cancer. The few studies on the relevance of prognostic factors, such as MYC status in cutaneous AS, have reported inconclusive findings, with some authors reporting MYC amplification only in postirradiation and lymphedema-associated AS and others reporting evidence of MYC amplification in idiopathic AS. We analyzed 17 cases of cutaneous AS (6 idiopathic AS, 10 postirradiation AS, and 1 lymphedema-associated AS) treated at our institute between 2000 and 2015. Follow-up data were available in all cases. We compared the presence/absence of MYC amplification by fluorescence in situ hybridization (FISH) and immunohistochemical (IHC) MYC overexpression in the different AS subtypes. We also investigated potential associations between MYC amplification and prognosis. MYC amplification was observed by FISH in 6 of 14 informative cases. The positive cases were all secondary AS (5 postirradiation AS and 1 lymphedema-associated AS). IHC detected MYC overexpression in 8 of 15 informative cases (7 secondary AS and 1 idiopathic AS). In conclusion, MYC amplification and MYC overexpression were detected almost exclusively in secondary AS. No associations were found between MYC amplification/overexpression and prognosis. We found MYC amplification or overexpression in a similar proportion of the patients who died and who were still alive at the end of the study. In the group of 9 patients who died, MYC was detected by FISH in 4 cases and by IHC in 5. The corresponding figures in the group of 6 patients still alive were 2 by FISH and 3 by IHC.

Cutaneous apocrine adenocarcinoma (CAA) is a rare adnexal neoplasm that histologically can mimic breast carcinoma metastatic to the skin or apocrine carcinoma arising in ectopic breast tissue. It can present with a wide range of clinical modalities and can often simulate many benign processes, which delays its diagnosis and hinders its prognosis. We describe a case of a 33-year-old man who had a short-evolution small nodule in the right axilla with local lymph node metastases. The immunohistochemical characterization was closer to that of breast adenocarcinoma than to an adnexal neoplasm. This was established as the main differential diagnosis. Diagnosis of cutaneous apocrine adenocarcinoma may be difficult and immunomarkers are not specific. The anatomical criteria and systemic investigation are mandatory to establish the correct diagnosis.

The different features of spitzoid melanoma are not well characterized in the literature, and the lesion often has to be described in comparison with Spitz nevus. We evaluated the histopathological appearance of spitzoid melanoma by reviewing all spitzoid melanomas treated at our hospital and all referrals from 1998 to 2010. The final study sample comprised 18 cases, 11 from our institution and 7 referrals from other centers. We recorded clinical parameters (eg, age, sex, site, time between onset and excision, recurrence, and death) and a series of histopathological parameters (eg, size, ulceration, symmetry, Clark level, Breslow thickness, cell density, atypia, mitosis). Clinical and histopathological criteria were not available for the 7 referrals. Mean age was 35.2 years (15-56), and 8 patients were women. Mean size of the lesions was 7.27 mm (Clark III/IV and Breslow 2.51 mm), and these were found on the limbs and trunk. Cell density was high in 10 cases and atypia present in 9 (marked in 1). Mitoses were observed in 8 cases (atypical in 4, clusters in 4). Maturation was absent in 9 cases and zonation in 8. Our analysis revealed 5 previously undefined subtypes of spitzoid melanoma (genuine (7 cases), uniform (5 cases), packed (5 cases), polypoid (3 cases) and pigmented (2 cases)]. Four cases showed 2 patterns at the same time. The most useful parameters for the differential diagnosis were cell density, mitosis, zonation, infiltration pattern, and consumption of the epidermis. Assignation of a spitzoid melanoma to 1 of more of our 5 subtypes can enable a more confident diagnosis to be made.

Cutaneous epithelioid angiomatous nodule is a peculiar and recently recognized vascular proliferation. Clinically, these lesions affect different areas of the body and histologically are characterized by a well-circumscribed, mainly unilobular, solid proliferation of endothelial cells with prominent epithelioid features. The cytoplasm is abundant and eosinophilic, and many of the neoplastic cells contain prominent vacuoles. Inflammatory infiltrates are variable. All the cases reported thus far have followed a benign course. We report 10 additional cases of this curious entity, including 2 which presented in an eruptive fashion and 5 that were located on the head and neck. We also discuss the histological differential diagnoses with other epithelioid proliferations and propose categorization within the spectrum of epithelioid hemangioma.