Pyoderma Gangrenosum after Breast Cancer Resection: A Less-invasive and Early Treatment Using the Skin around Ulcers.

Surgical invasion is a risk factor of pyoderma gangrenosum (PG). A total of 25% of postoperative PG cases were reported to occur after breast surgeries, including bilateral breast reduction and breast reconstruction following cancer resection. Immunosuppressive therapy and less-invasive wound therapy are necessary; however, the complete healing of ulcers takes 5.1 months on average. We herein report a case of skin grafting under a surgical concept of less-invasive and short-term treatment. An 82-year-old woman complained of a high fever and severe pain at her breast wounds after bilateral breast cancer resection. Although we performed emergency debridement surgery to remove the necrotic tissue, suspecting surgical site infection and inflammation, her high fever persisted. She was diagnosed with PG because of the physical findings of characteristic painful, sterile ulcerations, bullae and pustules, and the pathological abundance of neutrophils in the absence of infection and vasculitis. Oral administration of prednisolone 30 mg/day improved the symptoms, and we applied negative-pressure wound therapy (NPWT) from day 16 following debridement surgery. After the gradual reduction of oral steroid intake to 12.5 mg/day, we performed skin grafting surgery. To limit the surgical invasion, we used the surplus skin around the ulcers. Split-thickness mesh skin grafts were fixed by NPWT to avoid the use of tie-over sutures. We achieved short-term treatment of PG with a less-invasive surgical strategy using skin around the ulcers and NPWT.

Immunohistochemistry of the oncofetal protein IMP3 is helpful in the diagnosis of intravascular large B-cell lymphoma using skin biopsy.

BACKGROUND: The oncofetal protein insulin-like growth factor 2 mRNA binding protein-3 (IMP3) is expressed in various cancers. In this study, we examined the diagnostic utility of IMP3 immunohistochemistry in the context of intravascular large B-cell lymphoma (IVL). METHODS: We obtained 25 skin biopsy (SB) specimens diagnosed as IVL and nine IVL-negative SB specimens from 27 IVL patients. Additionally, 27 negative SB specimens from 26 non-IVL patients were obtained from our pathology archives. We performed IMP3 immunohistochemistry on these 61 SB specimens, considering IMP3 expression in any mononuclear cell as positive. In selected cases, triple immunostaining for IMP3, PAX5, and CD34 was performed to analyze the origin and location of IMP3-positive cells. RESULTS: IMP3 was expressed in most intravascular lymphoma cells in all the 25 SB specimens diagnosed as IVL. Furthermore, our evaluation revealed the presence of intravascular IMP3-positive B-cells in five of the nine negative SB specimens from IVL patients; however, this was not observed in the 27 SB specimens from non-IVL patients. CONCLUSION: IMP3 was expressed in most IVL cells, and IMP3 immunohistochemistry could serve as a sensitive diagnostic aid for detecting IVL cells in SB.

Maturing papillomatous nevoid melanoma in the scalp mimicking recurrent melanocytic nevus: A case report of previously undescribed subtype of nevoid melanoma.

Nevoid melanoma is a subtype of melanoma that histologically resembles a melanocytic nevus. Two subtypes have been proposed for nevoid melanoma, namely papillomatous and maturing. Here, we report the case of a 67-year-old woman who developed two nevoid melanomas on her scalp with composite histological features of papillomatous and maturing subtypes after electrocautery of a nearby solitary scalp papule. The histology of both lesions was very similar, papillary in shape, and both comprised two melanocyte populations, including large atypical melanocytes and small non-atypical melanocytes. Whole-exome sequencing was performed in one of the two lesions, which revealed a high mutation burden (17 mutations/megabase) with co-deletion of CDKN2A. Additional immunohistochemistry revealed that the large and small melanocytes in both lesions were completely negative for p16 and MTAP. A final diagnosis of nevoid melanoma was made. To our knowledge, this is the first report of a nevoid melanoma with both features of papillomatous and maturing subtypes. Pathologists should be aware of this subtype of melanoma to avoid misdiagnosis as a mitotically active melanocytic nevus. In this case, immunohistochemistry for p16 and MTAP, in addition to molecular analysis, helped in the final diagnosis.

Giant Pilomatrical Tumor With Broad Epidermal Components: An Example of Histological Diversity and a Potential Diagnostic Pitfall of Tumors With Pilomatrical Differentiation.

ABSTRACT: The diagnosis of pilomatricoma, the most common matrical tumor, is generally straightforward; however, it exhibits diverse histology associated with various morphological stages and several clinical variants, and matrical differentiation can occur in various neoplastic diseases. A 56-year-old man was admitted to our hospital to resect an 11.0-cm skin tumor on his right shoulder. Because of its large size and surface irregularities, including multiple erosions and ulcers, cutaneous malignancies were clinically suspected. Histologically, the tumor formed numerous nodules with marked matrical differentiation in the superficial to deep dermis. Although the tumor was macroscopically asymmetrical and irregular, each nodule was microscopically round-shaped and consisted of basaloid cells without marked atypia, atypical mitoses, or lymphovascular invasion. Immunohistochemically, the tumor cells were positive for beta-catenin, LEF-1, and PHLDA-1, consistent with their pilomatrical differentiation. We diagnosed the case as a giant pilomatrical tumor with uncertain malignant potential, considering its "contradictory" features, namely, the worrisome histoarchitecture, such as the asymmetrical silhouette, but bland-looking cytological appearance. Unlike typical pilomatrical tumors, this tumor contained numerous epidermal components with features similar to those of the dermal components, resulting in a unique macroscopic and histological appearance. Our case broadens the known histological diversity of pilomatrical tumors.

EBV-positive Mucocutaneous Ulcer With Small Lymphocytic Infiltration Mimicking Nonspecific Ulceration.

Epstein-Barr virus (EBV)-associated lymphoproliferative disorder may resemble nonspecific inflammation. We report 3 cases of immunosuppressed adult patients with small lymphocytic EBV ulcers in the skin and oral mucosa, characterized by a lack of atypical lymphocytic infiltration. All 3 cases were diagnosed in routine practice. For comparisons, cases of conventional Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) were reviewed which were extracted from our pathology archives (n=11). The present patients were 2 females and 1 male, aged above 70 years. The primary disease was rheumatoid arthritis (n=2) and dermatitis herpetiformis (n=1). The main source of immunosuppression was prednisolone (n=2) and methotrexate (n=1). The ulcers were located in the oral cavity, buttock, and/or external genitalia. Histology evaluation revealed nonspecific lymphocytic infiltration. Epstein-Barr virus-encoded small RNA (EBER)-positive cells were small and coexpressed CD20. The number of EBER-positive cells ranged from 52 to 132/HPF, which was within the range of that observed in the reviewed conventional EBVMCUs (range, 48 to 1328; median, 121). All 3 cases regressed spontaneously or by the reduction of immunosuppressants. Although the present cases lacked cytologic atypia, those clinical course and loads of EBER-positive cells (>50/HPF) suggested EBV involvement. Current cases of EBVMCU with small lymphocytic infiltration underscore the need for EBER in situ hybridization when an etiology of ulcer with predominant lymphocytes in an immunosuppressed patient is unclear.