Exogenous Ochronosis (EO): Skin lightening cream causing rare caviar-like lesion with banana-like pigments; review of literature and histological comparison with endogenous counterpart

Ochronosis is a cutaneous disorder caused by the accumulation of phenols, either endogenously as homogentisic acid in patients with alkaptonuria (autosomal recessive disorder with deficiency of the enzyme homogentisic acid oxidase), or exogenously in patients using phenol products such as topical creams containing hydroquinone or the intramuscular application of antimalarial drugs. Exogenous ochronosis (EO) typically affects the face and was reported in patients with dark skin such as Black South Africans or Hispanics who use skin-lightening products containing hydroquinone for extended periods. Recently more cases have been reported worldwide even in patients with lighter skin tones, to include Eastern Indians, Asians, and Europeans. However, just 39 cases of EO have been reported in the US literature from 1983 to 2020. Here we present two cases; a 69 and a 45-year-old female who were seen for melasma, given hydroquinone 4% cream daily and tretinoin 0.05%. Both patients noticed brown spots on their cheeks, which progressively enlarged and darkened in color. The diagnosis of ochronosis was confirmed by characteristic histopathological features on the punch biopsy. Unfortunately, neither patient responded to multiple treatments (to include, tazarotene 0.1% gel and pimecrolimus ointment, topical corticosteroids, and avoidance of hydroquinone containing products). We also present a case of classic (endogenous) ochronosis in a patient with alkaptonuria to picture the histological similarities of these two entities. EO is an important clinical consideration because early diagnosis and treatment may offer the best outcome for this notoriously refractory clinical diagnosis.

Primary pulmonary undifferentiated pleomorphic sarcoma (PPUPS)

Undifferentiated pleomorphic sarcoma (UPS) is a high-grade pleomorphic neoplasm with no identifiable line(s) of differentiation using currently available diagnostic techniques. Therefore, it is essentially a diagnosis of exclusion, which requires generous tissue sampling, adequate contextually interpreted immunohistochemistry, and relevant molecular studies. UPS is a common soft tissue sarcoma (historically one of the entities referred to as malignant fibrous histiocytoma (MFH)), which can develop in various organs, but lung involvement is usually due to metastasis. Primary Pulmonary UPS (PPUPS) is exceptionally rare and here we present a 66-year-old man who presented with anemia and weight loss, found to have a 17 cm right lung mass with invasion to the chest wall and diaphragm. Extensive sampling and immunohistochemistry studies failed to reveal any line of differentiation. Upon exclusion of a possible extrapulmonary origin, a diagnosis of PPUPS was rendered. In addition, we reviewed all 84 previously reported cases of PPUPS/PPMFH in the literature since 1979 and summarized the clinical information.

Round cell liposarcoma of scrotum with indolent course in young adult.

Myxoid/Round cell liposarcoma accounts for one-half of all liposarcomas and occurs as the second most common subtype. Both myxoid and round cell types share clinical, histological features and are accepted to represent a spectrum of lesions ranging from pure myxoid to near completely round cell liposarcoma. Round cell liposarcoma is highly metastatic and is classified as high grade and poorly differentiated myxoid sarcoma. Typical non-round cell myxoid liposarcoma is less metastatic and has more favorable prognosis. Karyotypic study of myxoid and round cell liposarcomas reveal a characteristic reciprocal translocation t (12;16)(q13;p11) resulting in the fusion of CHOP gene with TLS gene in more than 90% of cases. Most masses within the scrotal sac arise from the testis proper, and less likely from the extratesticular tissue. Liposarcoma represents approximately 20% of malignant extratesticular neoplasms, with the well differentiated subtype being the most common. Myxoid/round cell liposarcoma and round cell liposarcoma are rarely encounter in extratesticular soft tissue. We reported a rare case of round cell liposarcoma (high grade myxoid liposarcoma) of extratesticular tissue. To our knowledge, this is the first case of a large size (> 5cm) round cell liposarcoma arising from soft tissue within the scrotal sac of young adult with indolent course. Simple excision or enucleation are inadequate therapies and wide excision of the hemiscrotum including inguinal soft tissue and nodes is recommended. The role of retroperitoneal lymph node dissection and adjuvant chemotherapy remains controversial.