Cutaneous Involvement in Plasma Cell Myeloma

Proteomic and Clinicopathologic Assessment of Penile Amyloidosis: A Single Institutional Review of 12 Cases

OBJECTIVES

There is a paucity of data on penile amyloidosis. We aimed to assess the frequency of different amyloid types in surgical specimens from the penis involved by amyloidosis and correlate relevant clinicopathologic parameters with proteomic findings.

METHODS

Since 2008, our reference laboratory has performed liquid chromatography/tandem mass spectrometry (LC-MS/MS) for amyloid typing. The institutional pathology archive and reference laboratory database were queried to retrospectively identify all penile surgical pathology specimens with LC-MS/MS results between January 1, 2008, and November 23, 2022. Archived H&E-stained and Congo red-stained sections were re-reviewed.

RESULTS

Twelve cases of penile amyloidosis were identified, which represented 0.35% (n = 3,456) of penile surgical specimens. AL-type amyloid was most frequent (n = 7), followed by keratin-type amyloid (n = 3) and ATTR (transthyretin)-type amyloid (n = 2). AL-type amyloid cases often showed diffuse dermal/lamina propria deposition, whereas all keratin-type amyloid cases were localized to the superficial dermis. Two cases with keratin-type amyloid had concomitant cutaneous findings (penile intraepithelial neoplasia and condyloma).

CONCLUSIONS

This series, the largest to date, demonstrates that penile amyloidosis has a heterogeneous proteomic landscape. To the best of our knowledge, this is the first study describing ATTR (transthyretin)-type penile amyloid.

Dermatological manifestations of hematologic neoplasms. Part I: secondary specific skin lesions

Cutaneous manifestations occur during the course of hematologic malignancies and precede, follow, or are late events in relation to the diagnosis. They result from paraneoplastic phenomena, tumor infiltrations, and immunosuppression resulting from the hematologic neoplasia itself or its treatment. The dermatologist must be aware of these conditions, which can help both in the diagnosis of the underlying disease and in the reduction of patient morbidity. This review (part I) addresses skin lesions associated with direct infiltration by systemic hematologic malignancies.

PRAME Expression as Helpful Immunohistochemical Marker in Rhabdoid Melanoma

Background: Rhabdoid melanoma is a rare variant of malignant melanoma with characteristic cytomorphologic features. Due to the potential loss of conventional melanocytic markers, histopathologic diagnosis is often challenging. We hypothesize that immunostaining for PReferentially expressed Antigen in MElanoma (PRAME) might have the potential to uncover the melanocytic origin of these dedifferentiated tumors. Methods: Four cases of rhabdoid primary melanomas were assessed by immunohistochemistry for expression of PRAME and conventional melanocytic markers. Immunohistochemical expression patterns were analyzed in the rhabdoid primaries and, if available, associated metastases. Results: All four cases of rhabdoid primary melanomas showed a strong nuclear positivity for PRAME, while the expression of conventional melanocytic markers S100, MART-1, SOX-10 and HMB-45 was variable between the analyzed cases. Conclusions: In summary, we report four cases of rhabdoid primary melanoma with high to intermediate expression of PRAME despite the partial and variable loss of other melanocytic markers. Hence, PRAME might facilitate the recognition of this highly aggressive entity to avoid misdiagnosis due to histopathologic pitfalls.

Cutaneous Multiple Myeloma

Multiple myeloma is a plasma cell dyscrasia characterized by abnormal bone marrow clonal plasma cells, histological confirmation of plasmacytoma, monoclonal protein in serum or urine, and evidence of end-organ damage. Organ involvement in multiple myeloma manifests as CRAB (hyperCalcemia, Renal insufficiency, Anemia, lytic Bone lesions). Cutaneous complications in multiple myeloma have been reported in many different phenotypes such as cryoglobulinemia rash, bruising, amyloid deposition, and squamous cell carcinoma. However, cutaneous metastasis of multiple myeloma is very rare with fewer than 100 cases described in the literature so far. Here, we present a case of biopsy-confirmed primary cutaneous multiple myeloma. Our case has other less common features of multiple myeloma such as renal amyloidosis and a coexisting malignant melanoma. This case report describes a unique presentation of multiple myeloma to understand the disease better.