A Tale of Two Tumors: A Collision Tumor of Atypical Fibroxanthoma and Basal Cell Carcinoma.

ABSTRACT: A collision tumor is an infrequent phenomenon characterized by the presence of 2 histologically distinct tumor types (either benign or malignant) occurring within the same specific anatomical site. We describe a rare case of co-occurrence of basal cell carcinoma and atypical fibroxanthoma presenting as a single lesion on the scalp in a 76-year-old man. The lesion was clinically suspicious for basal cell carcinoma and biopsied. Histologic examination showed 2 distinct tumors, one with basaloid cells and the other one with pleomorphic spindle cells colliding and growing together. Immunohistochemical stains were crucial in establishing the diagnosis. This presentation is exceedingly rare and requires additional evaluation for diagnosis.

A Rare Case of Varicella Zoster Infection in Hemorrhoids in a Patient With Inflammatory Bowel Disease.

ABSTRACT: Hemorrhoids are normal anatomical structures in the anus. When symptomatic, they prompt medical attention due to pain, rectal bleeding, and discomfort. Treatment includes dietary modifications, rubber band ligations, sclerotherapy, cryotherapy, or hemorrhoidectomy. Histologic examination is important to rule out incidental findings, such as perianal intraepithelial neoplasia, anal carcinoma, melanoma, or coexisting infections. Special attention should be given when patient is immunocompromised. We present a case of a 41-year-old man with a history of ulcerative colitis on adalimumab who presented with anal lesions. He was diagnosed with hemorrhoids and surgically treated. Microscopic examination confirmed the diagnosis of hemorrhoids. However, foci of epithelium with viral cytopathic effects were noted. A varicella zoster virus (VZV)-specific immunostain was positive in the areas of interest confirming the diagnosis of the VZV infection limited to the hemorrhoids. Combined herpes simplex virus type 1 and 2 (HSV 1 and HSV 2) immunostain was also performed and was negative. Anal herpes has been widely described in the literature, particularly in immunocompromised patients. However, isolated VZV infection in hemorrhoids to the best of our knowledge has never been reported.

Diagnostic utility of SOX10 immunostaining in benign lichenoid keratosis: A study of 21 cases.

BACKGROUND: Benign lichenoid keratosis (BLK) is a cutaneous lesion that can clinically mimic malignancy and may represent regression of a pre-existing lesion. BLK may show epidermal pseudo-nests prompting evaluation for a melanocytic lesion. False positivity of MART-1/Melan-A immunostaining in pseudonests has been showed; however, the value of SRY-related HMG-box 10 (SOX10) staining in BLK with features suspicious for a melanocytic proliferation has not been previously reported. METHODS: Twenty-one cases of BLK from 2015 to 2020 were identified. Slides were reviewed and SOX10 immunohistochemistry was performed on each case. Subsequently, Melan-A immunohistochemical staining was performed on all cases. RESULTS: In 10 cases (47.6%), unexpected SOX10 staining was seen in rare to numerous small, single cells in the epidermis above the basal cell layer. No malignancy was identified. Of the 10 cases, 8 (80%) showed suprabasal SOX10 staining did not show similar suprabasal Melan-A staining; 2 (20%) cases showed scattered suprabasal cells positive for Melan-A. CONCLUSION: SOX10 immunostaining in BLK can highlight scattered cells in the epidermis (not easily noticeable on routine stain). Performing SOX10 immunostain alone on BLK can prompt a misdiagnosis of a melanocytic lesion and should be done with caution.

Prognostic model for patient survival in primary anorectal mucosal melanoma: stage at presentation determines relevance of histopathologic features.

Pathological staging of primary anorectal mucosal melanoma is often performed according to the American Joint Commission on Cancer (AJCC) guidelines for cutaneous melanoma, as an anorectal melanoma-specific staging system does not exist. However, it remains unknown whether prognostic factors derived for cutaneous melanoma also stratify risk in anorectal melanoma. We retrospectively determined correlations between clinicopathological parameters and disease-specific survival in 160 patients. Patients were grouped by clinical stage at presentation (localized disease, regional or distant metastases). Cox proportional hazards regression models determined associations with disease-specific survival. We also summarized the somatic mutations identified in a subset of tumors analyzed for hotspot mutations in cancer-associated gene panels. Most of the patients were white (82%) and female (61%). The median age was 62 years. With a median follow-up of 1.63 years, median disease-specific survival was 1.75 years, and 121 patients (76%) died of anorectal melanoma. Patients presenting with regional (34%) or distant metastases (24%) had significantly shorter disease-specific survival compared to those with disease localized to the anorectum (42%). Of the 71 anorectal melanoma tumors analyzed for hotspot genetic alterations, somatic mutations involving the KIT gene (24%) were most common followed by NRAS (19%). Increasing primary tumor thickness, lymphovascular invasion, and absence of regression also correlated with shorter disease-specific survival. Primary tumor parameters correlated with shorter disease-specific survival in patients presenting with localized disease (tumor thickness) or regional metastases (tumor thickness, absence of regression, and lymphovascular invasion), but not in patients presenting with distant metastases. Grouping of patients according to a schema based on modifications of the 8th edition AJCC cutaneous melanoma staging system stratified survival in anorectal melanoma. Our findings support stage-specific associations between primary tumor parameters and disease-specific survival in anorectal melanoma. Moreover, the AJCC cutaneous melanoma staging system and minor modifications of it predicted survival among anorectal melanoma patients.

"Puffy shirt appearance": Cell crowding at low magnification may represent nevoid melanoma.

BACKGROUND: Melanoma, particularly nevoid melanoma, can masquerade as benign. Helpful differentiating features include nuclear pleomorphism, atypia, prominent nucleoli, absent maturation, and increased mitotic figures. These can be subtle and easily missed unless carefully sought. Thus, the "puffy shirt appearance" concept was born from a Seinfeld episode in which the namesake character unintentionally agreed to wear a pirate-like puffy shirt. Consequently, he found himself out of place, sporting an outfit with "too much shirt in too little space". Similarly, at low-power, nevoid melanoma appears to have "too many cells in too little space". This is more pronounced and easier to appreciate when there is an associated nevus, where crowded, subtly malignant melanocytes stand out from the evenly distributed, more spaced out benign melanocytes. METHODS: Twelve practicing dermatopathologists familiar with the puffy shirt concept in the context of melanoma were surveyed. RESULTS: Hundred percent of participants found it most helpful as a triaging tool, prompting additional work up including higher magnification evaluation, additional levels, consultation, and/or immunohistochemistry. CONCLUSIONS: The crowded cells in the "puffy shirt appearance" catch the eye and should provoke a more thorough inspection of the lesion. This sign is not pathognomonic for melanoma, but prompts more careful evaluation and helps prevent misdiagnosis.

Primary cutaneous Hodgkin-like polymorphic post-transplant lymphoproliferative disorder.

Post-transplant lymphoproliferative disorder (PTLD) is an uncommon complication after solid-organ transplants and hematopoietic stem cell transplants. Isolated involvement of the skin without systemic involvement in PTLD is extremely rare. Primary cutaneous PTLD is generally categorized as either cutaneous T-cell lymphoma or cutaneous B-cell lymphoma, with variable Epstein-Barr virus (EBV) positivity. Herein, we describe an exceedingly uncommon case of a primary cutaneous Hodgkin-like polymorphic PTLD. A man in his 60s, with a history of kidney transplant, presented with a 5-week history of two indurated plaques. Clinical, histologic and immunohistochemical findings were consistent with primary cutaneous Hodgkin-like polymorphic PTLD. Reduction in immunosuppression led to resolution of his lesions. This case highlights a rare case of primary cutaneous Hodgkin-like PTLD and increases awareness of this uncommon post-transplant complication. It also underscores the importance of collaboration between dermatology, hematology, dermatopathology and hematopathology in order to diagnose challenging cases.

Necrotizing Granulomatous Dermatitis and Panniculitis Masquerading as T Cell Lymphoma.

A 51-year-old white woman with a past medical history significant for steroid-dependent ulcerative colitis, rheumatoid arthritis, and diabetes mellitus presented to the hospital with fever and painful, erythematous subcutaneous nodules on the medical aspects of both thighs. Histopathologic examination showed features suggestive of an abscess, but her condition failed to improve with intravenous broad-spectrum antibiotics. Molecular studies detected T cell receptor-ß gene rearrangements. The lesions later exhibited signs of necrosis, requiring multiple debridements as well as therapy with hyperbaric oxygen. She was later referred to the MD Anderson Cancer Center for evaluation for possible subcutaneous panniculitis-like T cell lymphoma.

Recurrence of moderately dysplastic nevi with positive histologic margins.

BACKGROUND: The Pigmented Lesion Subcommittee of the Melanoma Prevention Working Group recently published a consensus statement that incompletely excised moderately dysplastic nevi (MDN) without clinical residual pigmentation can be observed and not re-excised. However, data regarding recurrence of MDN with positive histologic margins are quite scant. OBJECTIVE: We sought to extend the reported findings with a study to determine the recurrence rate of MDN with positive histologic margins. METHODS: We performed a retrospective study on MDN with positive histologic margins that were not re-excised and for which at least 1 year of clinical follow-up was available. RESULTS: We found a total of 147 such nevi from January 1, 2007, to December 31, 2013. Six MDN (5 compound and 1 junctional) or 4% recurred with an average recurrence time of 1.7 years. All of these MDN were evaluated by shave biopsies. LIMITATIONS: Subjectivity in grading of atypia is a limitation of this study. CONCLUSION: These data from a large study focusing exclusively on recurrence of MDN with positive histologic margins support the conclusion of the Pigmented Lesion Subcommittee that incompletely excised MDN do not require re-excision.

Multiple clear cell acanthomas and a sebaceous lymphadenoma presenting in a patient with Cowden syndrome - a case report.

Cowden syndrome (CS) is an uncommon autosomal dominant multiorgan/system genodermatosis. It is characterized by the development of multiple hamartomas of endodermal, mesodermal and ectodermal origin, an increased lifetime risk of breast, thyroid, endometrial and other cancers and an identifiable germline mutation. Mucocutaneous hamartomas are the most common lesions seen and mainly include facial trichilemmomas, oral mucosal papillomas and benign acral keratoses. Herein, we report a case of a 63-year-old Caucasian male with a long-established diagnosis of CS and history of thyroid cancer, colonic polyps, and innumerable trichilemmomas, seborrheic keratoses, squamous papillomas and non-melanoma skin cancers excised in the past. He presented in four separate occasions with small skin-colored papulonodular lesions that upon excision revealed to be clear cell acanthomas. He also developed a tumor in the preauricular area that was completely resected and was found to be a sebaceous lymphadenoma (SLA) of the parotid gland. This is to our knowledge, the second report of clear cell acanthoma and also the second reported case of SLA in a patient with CS.

Angiosarcoma of the Eyelid With Superimposed Enterobacter Infection.

Angiosarcoma is a rare, aggressive, malignant endothelial neoplasm with a variable clinical presentation. The authors describe a case of angiosarcoma involving the eyelid that was complicated by a superimposed Enterobacter infection. Following positive cultures for E. aerogenes and multiple biopsies suspicious but not definitive for angiosarcoma, a final biopsy was consistent with angiosarcoma.

Hidradenoma papilliferum associated with pregnancy: a case report.

We present the case of a 33-year-old female who developed a cystic nodule on the vulva during pregnancy. Immediately following Cesarean section, the lesion was biopsied and histologic examination revealed a dermal tumor composed of glandular structures arranged in a labyrinth pattern. The glandular structures displayed cytoplasmic vacuolization, large atypical nuclei, prominent nucleoli and scattered eosinophilic luminal secretions. Immunohistochemistry showed the tumor cells to be diffusely positive for CK7 and progesterone receptor with focal expression of mammaglobin and GCDFP-15. The tumor cells were negative for estrogen receptor and CK20. These histologic and immunophenotypic findings were consistent with hidradenoma papilliferum. Our unusual (and to our knowledge first reported) case demonstrates hidradenoma papilliferum in association with pregnancy and raises the possibility of cytologic atypia and lactational change being secondary to hormonal changes in pregnancy.

Atypical histopathologic features in a melanocytic nevus after cryotherapy and pregnancy.

Melanocytic nevi can undergo clinical and histopathologic changes during pregnancy, as well as after various forms of surgical and nonsurgical trauma. We report the case of a 9-month postpartum 29-year-old female who presented to her dermatologist with a clinically worrisome nevus. This nevus had been treated with liquid nitrogen by her primary care physician 6 months prior to presentation. Histopathologic evaluation revealed a crowded proliferation of atypical melanocytes at the dermal-epidermal junction overlying a scar. The dermal component contained scattered mitotic figures. A combined MART-1, tyrosinase and Ki-67 immunohistochemical study showed foci of increased melanocytic proliferation. These atypical features were interpreted as associated with both the prior cryotherapy, as well as her recent pregnancy. Knowledge of the clinical context in evaluating difficult melanocytic lesions is essential.

Hydroa vacciniforme: a rare photodermatosis.

Hydroa vacciniforme (HV) is a rare photodermatosis characterized by a recurrent vesiculopapular eruption with varioliform scarring. The pathogenesis remains unknown. Herein we present a case to emphasize the importance of recognizing this condition and its clinical mimickers, which include other photodermatoses and lymphoma.

Cutaneous carcinosarcoma: further insights into its mutational landscape through massive parallel genome sequencing.

Cutaneous carcinosarcoma (CCS) is an extraordinarily rare neoplasm with a biphasic morphological pattern exhibiting both epithelial and sarcomatoid components. Although its histogenesis and biological aspects remain poorly understood, previous studies have postulated that this tumor may arise from single cancer stem cells which subsequently differentiate into distinct tumor lineages. In this study, we explored a wide array of mutational hot spot regions, through high-depth next-generation sequencing of 47 cancer-associated genes in order to assess the mutational landscape of these tumors and investigate whether the epithelial and mesenchymal components shared the same genetic signatures. Results from this study confirm that despite their striking phenotypic differences, both elements of this infrequent tumor indeed share a common clonal origin. Additionally, CCS appears to embrace a heterogeneous spectrum with specific underlying molecular signatures correlating with the defining epithelial morphotype, with those carcinosarcomas exhibiting a squamous cell carcinoma epithelial component exhibiting diverse point mutations and deletions in the TP53 gene, and those with a basal cell carcinoma morphotype revealing a more complex mutational landscape involving several genes. Also, the fact that our findings involve several targetable gene pathways suggests that the underlying molecular events driving the pathogenesis of CCS may represent future potential targets for personalized therapies.

Cutaneous leishmaniasis in Cuban immigrants to Texas who traveled through the Darién Jungle, Panama.

Cutaneous leishmaniasis is rarely seen in the United States. Four Cuban immigrants traveled along the same route at different times from Cuba to Ecuador, then northward, including through the Darién Jungle in Panama. These patients had chronic ulcerative non-healing skin lesions and were given a diagnosis of leishmaniasis.